I E C 6 1 8 5 0 : T h e n e w a p p ro a c h 7P roducts for the standard 16 Ve ri fi c a ti o n a n d v a li d a ti o n 2 3 C ase studies of IEC 61850 38 S pecial R eport IEC 61850 review A B B The corporate technical journal 2 A B B review special report C o m m u n i c a ti o n i s m o re th a n e x - c h a n g i n g d a ta ; i t m e a n s g lo b a lly u n d e rs ta n d a b le i n fo rm a ti o n b a s e d o n s y n ta x a n d s e m a n ti c . T h i s i s b e h i n d I E C 6 1 8 5 0 , th e to p i c o f th i s i s s u e o f ABB Review S p e c i a l R e p o rt. E le c tri c e n e rg y i s th e b a c k b o n e o f o u r g lo b a l s o c i e ty. I ts re li a b le s u p - p ly fro m c o n v e n ti o n a l a n d re n e w - a b le s o u rc e s v i a c o m p le x n e tw o rk s re q u i re s s e a m le s s c o n tro l th a t i s o n ly p o s s i b le w i th th e h e lp o f a s ta n d a rd p ro v i d i n g a h i g h -le v e l a n d c o m p re - h e n s i v e d e s c ri p ti o n o f th e i n fo rm a ti o n e x c h a n g e d . A B B s e rv e s th e p o w e r s y s te m w i th s u b s ta ti o n s a s w e ll a s u ti li ty a u to m a ti o n s o lu ti o n s . L e a rn m o re a b o u t I E C 6 1 8 5 0 a n d A B B ’ s c o m m i tm e n t fro m th e o n s e t b o th to d e v e lo p i n g th e s ta n d a rd a n d i m p le - m e n ti n g i t i n p ro d u c ts a n d s y s te m s o lu ti o n s . C ontents 7 1 3 1 6 2 3 2 9 3 3 3 8 4 2 4 7 5 3 5 7 6 2 T h e c o n c e p t o f I E C 6 1 8 5 0 A new approach for com m unication in substation autom ation and beyond C o m m o n d e n o m i n a to r C om m on com ponents have helped A B B adopt the IEC 61850 substation com m unication standard in record tim e P u s h i n g th e li m i ts A B B product developm ent based on the IEC 61850 standard Ve ri fi e d a n d v a li d a te d A B B has its ow n system verification and validation center A te s ti n g e n v i ro n m e n t A B B ’s com prehensive suite of softw are testing and com m issioning tools for substation autom ation system s N e x t g e n e ra ti o n s u b s ta ti o n s Im pact of the process bus I E C 6 1 8 5 0 a t w o rk Five case studies Wh e n tw o b e c o m e o n e IEC 61850 in com bination w ith A B B ’s aw ard-w inning Extended A utom ation S ystem 800xA is opening doors to new and cost-effective solutions I E C 6 1 8 5 0 E d i ti o n 2 From substation autom ation to pow er utility autom ation R e li a b le n e tw o rk i n g Im pact of m odern com m unication technology on system reliability S e a m le s s re d u n d a n c y B um pless Ethernet redundancy for substations w ith IEC 61850 I E C 6 1 8 5 0 – a s u c c e s s a ro u n d th e w o rld S ubstation autom ation system s pave the w ay to a sm arter grid The w ay forw ard P roject experience Enabling the sm art grid S m arter substations Innovation and developm ent B ackground 3 C o n te n ts A B B review special report 4 C la e s R y to ft H ead of Technology P ow er S ystem s division P e te r L e u p p H ead of P ow er S ystem s division M em ber A B B G roup Executive C om m ittee control the devices, and how conform ity to the standard should be tested. Follow ing its introduction, the im plem entation of IEC 61850 has advanced at a rem arkable pace. P erhaps never before has an industrial standard been accepted w ith such speed. W ithin tw o years of its release, a m ajority of the m arket w as dem anding IEC 61850 as the preferred com m unication protocol. It is increasingly being used for the integration of electrical equipm ent into distributed control system s in process industries. The fact that new application areas, such as hydro and w ind pow er are being added is yet another indication of its success. The bottom line is about how technology can low er costs, im prove reliability and enhance efficiency. IEC 61850 has a proven track record of deliverable benefits to both sm all and large utilities. C om m unication infrastruc- ture costs m oney to install, configure and m aintain. B ut the savings that IEC 61850 delivers by w ay of substation design, installa- tion, com m issioning, and operation com bined w ith new capabilities that are not practical or cost effective using legacy approaches, m akes it a w orthw hile investm ent. This special edition of ABB Review looks at this truly global and unifying standard from different angles and relates m any of our experiences based on the vast installed base w e have built during the years. W e shall also attem pt to take a peek into som e possible future developm ents in this area. W e hope you enjoy reading this dedicated special issue. P eter Leupp C laes R ytoft D e a r R e a d e r, S ubstations are key com ponents of the pow er grid, facilitating the efficient transm ission and distribution of electricity. They play a vital role in term s of m onitoring and controlling pow er flow s and provide the interconnection be- tw een generating facilities, transm ission and distribution netw orks and end consum ers. S ubstation autom ation system s m ake their control and m onitoring possible in real tim e and help m axim ize availability, efficiency, reliability, safety and data integration. For decades, the pow er sector w as geo- graphically split betw een tw o m ajor standards –IEC (International Electrotechnical C om m is- sion) and A N S I (A m erican N ational S tandards Institute). This often proved a deterrent to the developm ent of a global technology offering. IEC 61850 broke this deadlock. S ince its publication in 2004, it has been em braced by both the IEC and A N S I com m unities. The new standard w as designed to: P rovide a single protocol for a com plete substation Im plem ent a com m on form at to describe the substation and facilitate object m odel- ing of data required in the substation D efine the basic services required to transfer data using different com m unication protocols A llow for interoperability betw een products from different vendors The standardization w ork com m enced in the m id 1990s and continued for alm ost a decade, involving m ore than 60 experts from utility and technology providers across the globe. A B B w as very m uch a part of this process and som e of the contributors are represented in this report. IEC 61850 provides a standardized fram e- w ork for substation integration that specifies the com m unications requirem ents, the functional characteristics, the structure of data in devices, the nam ing conventions for the data, how applications interact and Editorial IEC 61850 –A unifying global com m unication standard 5 E d i to ri a l 6 A B B review special report 7 T h e c o n c e p t o f I E C 6 1 8 5 0 The concept of IEC 61850 K L A U S -P E T E R B R A N D , WO L F G A N G WI M M E R – T h e a b ility to c o p e w ith th e n a tu ra l m ig ra tio n o f te c h n o lo g y c o m b in e d w ith th e n e e d fo r in te ro p e r- a b ility a re ju s t s o m e o f th e re a s o n s th e I E C 6 1 8 5 0 , a n in te rn a tio n a l s ta n d a rd th a t d e n e s c o m m u n ic a tio n in a n d b e tw e e n e le c tric a l s u b s ta tio n a u to - m a tio n s y s te m s w a s d e v e lo p e d . U s in g it’ s o b je c t-o rie n te d h ie ra rc h ic a l d a ta m o d e l a p p ro a c h w ith h ig h -le v e l s ta n d a rd ize d s e m a n tic s , I E C 6 1 8 5 0 e n a b le s th e a b s tra c t d e n itio n o f d a ta ite m s a n d s e rv ic e s to n o t o n ly s p e c ify w h a t d a ta o r in fo rm a tio n n e e d s to b e e x c h a n g e d b u t a ls o th e m e c h a n ic s o f h o w it is to b e e x c h a n g e d u s in g m a in s tre a m c o m m u n ic a tio n a n d n e tw o rk in g ( m a in ly E th e rn e t) te c h n o lo - g ie s . I n a d d itio n , th e c o s t b e n e ts o f im p le m e n tin g I E C 6 1 8 5 0 c a n a lre a d y b e s e e n in th e s y s te m d e s ig n p h a s e a n d e x p e rie n c e d rig h t th ro u g h to th e c o m m is s io n in g a n d o p e ra tin g p h a s e s . A ll o f th e s e fa c to rs h e lp to e x p la in th e e a g e rn e s s a n d s p e e d w ith w h ic h th e rs t e d itio n o f th e s ta n d a rd h a s b e e n a c c e p te d a ro u n d th e g lo b e . A new approach for com m unication in substation autom ation and beyond S ubstation autom ation (S A ) is com m only used to control, protect and m onitor a substa- tion [1]. H ow ever, over the years advances in electronics, inform a- tion and com m unications technology have brought about sw eeping changes in the w ay substations are operated. The advent of softw are-based substation au- tom ation system s (hereafter referred to as S A system s) connected by serial links rather then rigid parallel copper w iring gradually becam e the norm rather than the exception. Though successful and w idely accept- ed, these system s w ere based on ei- ther the m anufac- turers’ow n propri- etary com m u nica- tion solutions or the defi ned use of com - m unication stan- dards from other application dom ains, such as D N P 3 or IEC 60870-5-104. These solutions m ade interoperability betw een devices from different suppliers, and som etim es even betw een different versions of devices from the sam e sup- plier, an engineering nightm are w hich could only be m itigated by expensive protocol conversion or re-engineering. The connection of the S A system w ith the sw itchgear and instrum ent trans- form ers w as still left to analog standards such as 1 A and 3 A for current trans- form ers, and 110 V and 220 V for voltage transform ers and contact circuits for sw itchgear operations. It took over 20 years before global forc- es, such as international suppliers and transnational utilities raised their voices to request a solution, in the form of a substation com m unication standard, to overcom e the interoperability prob- lem ➔ 1 . W hile interoperability w as a m a- jor concern, it w asn’t the only one. O nly too aw are of the dizzying pace at w hich technologies change, the authors of this new standard, know n as IEC 61850, also set about finding a w ay to create a “future -proof”standard that w ould be im m une U sing it’s object-oriented hier- archical data m odel approach w ith high-level standardized sem antics, IEC 61850 enables the abstract definition of data item s and services. 8 A B B review special report various technologies em ployed in a typi- cal substation. For exam ple, fast-chang- ing m ainstream com m unication technol- ogy w ill alw ays need to serve the slow er-changing requirem ents of protec- tion and substation autom ation. To facilitate the use of the standard for users, the identification of all transm itted data should not be based on a lim ited num ber schem e derived from contact term inal row s, but rather on the object- oriented grouping of data and a nam ing structure that uses standardized acro- nym s understandable to any substation engineer. In addition, configuration and engineering tools should be used to cre- ate system s w ith m inim um effort and w ith a m inim um risk of failure. T h e b a s i c a p p ro a c h o f I E C 6 1 8 5 0 To reach long-term interoperability, ie, to cope w ith the different tim e scales of function evolution in the dom ain substa- tion and w ith changing com m unication technology, the approach taken in the IEC 61850 standard separates the do- m ain related m odel for both data and com m unication services from the proto- cols, ie, the IS O /O S I seven-layer stack used to code and decode inform ation into bit strings for com m unication over a serial link. This approach not only ac- com m odates state-of-the-art com m uni- cation technology, but it also safeguards investm ents in applications and engi- neering (based on the object and com - and devices w ould need to be standard- ized, thus blocking any technical evolu- tion and functional com petition. N ever- theless it m ust be possible to exchange faulty IED s w ithin the lifetim e of the S A system . U sing IED s that are com - pliant w ith the sam e standard in term s of interoperability w ill facilitate easy exchangeability. F re e a rc h i te c tu re For a standard to be term ed “global,”it m ust support the operation philosophy of utilities around the w orld. It has to support an arbitrary allocation of func- tions to devices and should therefore be capable of supporting centralized and decentralized system architectures. L o n g -te rm s ta b i li ty G iven that the lifetim e of a substation (prim ary equipm ent) is betw een 40 and 60 years, it is anticipated that com po- nents of the S A system have to be ex- changed, on average, around tw o to three tim es during this period; som e com ponents m ay need replacem ents on a m ore regular basis. N aturally over tim e the substation w ill have to cope w ith the integration of new com ponents from the sam e or new suppliers, or it m ay need to be extended. The point is that irrespec- tive of the changes, interoperability m ust be m aintained indefinitely, or to be m ore specific, the standard has to be future- proof. This requirem ent not only applies to substation devices, but also to the S w ith yard G IS or A IS R elay room in G IS R elay house in A IS O perating room L e g a c y S A H a rd w i re d S A I E C 6 1 8 5 0 b a s e d S A L o c a ti o n 1 S u b s ta ti o n a u to m a ti o n ( S A ) a rc h i te c tu re fro m h a rd w i re s o v e r p ro p ri e ta ry p ro to c o ls to I E C 6 1 8 5 0 S C A D A -distribution, m etering C opper cables C opper cables C opper cables S ensors & actuators B ay cubicle B ay cubicle B ay cubicle to other bays to other bays 1 9 6 5 1 9 8 5 2 0 0 5 Ye a r G IS G IS G IS * The process bus is not a m ust in IEC 61850 but only an option M M I, C ontrol board C opper cables S tation bus and P rocess bus* according to IEC 61850 P roprietary S tation bus S erial com m unication (Fiber optics) S erial com m unication (Fiber optics) G atew ay G atew ay H M I H M I to any future technological develop- m ents. A s the IEC 61850 standard evolved, oth- er features, such as the definition of tw o tim e-critical services –the fast transm is- sion of trip-type signals and sam pled analog current and voltage values –w ere added. These tim e-critical services en- able the extension of the serial links to be used betw een any intelligent electronic device (IED ) and the electronic interfaces near the sw itchyard equipm ent. D em and- ing m arket requirem ents, such as the shortening of transfer tim es dow n to 3 m s and tim e synchronization in the order of 1 µs had also to be considered. P erhaps the cornerstone of the standard is the innovative extensible m arkup lan- guage or XM L-based substation configu- ration description language (S C L). S C L form ally describes the configuration of IED s in term s of functionality (eg, circuit breaker control, m easurem ents and sta- tus values) com m unication addresses and services (eg, reporting). It also de- scribes the sw itchyard layout and its re- lation to the functions im plem ented in the IED s. T h e e m e rg e n c e o f a n e w s ta n d a rd W hen the authors of the IEC 61850 stan- dard first sat together, they identified a list of m arket requirem ents that w ould in- fluence the form the new standard w ould take. The m ost im portant ones w ere in- teroperability, free architecture and long- term stability. I n te ro p e ra b i li ty To begin w ith, the standard m ust be able to support all functions in its application dom ain substation. Therefore, in addition to protection, autom ation, control and m onitoring functions, m any service func- tions, such as tim e synchronization, self supervision and version handling have also to be supported. These functions are executed by softw are im plem ented in the IED s. Interoperability in the S A sys- tem m eans that IED s from different sup- pliers or different versions from the sam e supplier m ust be able to exchange and use inform ation in real tim e w ithout any protocol converters and w ithout the need for hum an interpretation. It is im portant to distinguish interopera- bility from interchangeability. If IED s w ere also to be interchangeable, the functions Event recording Protection 9 T h e c o n c e p t o f I E C 6 1 8 5 0 physical device itself are dealt w ith by an LN class nam ed LP H D . O nly if a LN class for som e function is m issing it m ay be substituted by generic LN classes that have restricted sem antic m eaning. M ore dem anding, how ever, is the extension of LN s and data according to the strict and restrictive extension rules of the standard, including nam e spaces as unam biguous references to sem antic m eaning. These rules preserve interoperability, even in cases w here ex- tensions are required. For the functional identification of each data in the context of the sw itchyard, a hierarchical plant designation system shall be used for the designation of sub- station objects and functions preferably according to IEC 61346 [6]. T h e s e rv i c e s o f th e d a ta m o d e l Interoperability requires the standardiza- tion of not only the data objects but also the access to them . Therefore, standard- ized abstract services also belong to IEC 61850. The m ost com m on ones include: –R ead: reading data such as the value of an attribute –W rite: for exam ple w riting the value of a configuration attribute –C ontrol: controlling sw itching devices and other controllable objects using standardized m ethods such as “select before operate”or “direct operate” –R eporting: for exam ple, event driven reporting after value changes –Logging: the local storage of tim e- stam ped events or other historical data –G et directory: in other w ords, to read out the data m odel (im portant part of self-description) m unication service m odel). Therefore, the standard is future-proof. The m ap- ping of the data m odel to the com m uni- cation stack is also standardized in IEC 61850 to ensure interoperable com - m unication ➔ 2 . T h e o b je c t-o ri e n te d d a ta m o d e l The basic data m odel structure defined in the IEC 61850 standard is application independent. H ow ever, depending on the scope of the standard, the object m odel classes, as issued in edition 1 of the standard ➔ 3 [2], are related to the dom ain substation. O bject m odels for w ind pow er [3], hydro pow er [4] and dis- tributed energy resources [5] w ere added at a later date. A ll application functions, including the data interfaces to the pri- m ary equipm ent, are broken dow n into the sm allest feasible pieces, w hich m ay com m unicate w ith each other and, m ore im portantly, m ay be im plem ented sepa- rately in dedicated IED s. In IEC 61850, these basic objects are called logical nodes (LN s). The class nam e of the LN refers to the function the data objects belong to. The data objects contained in a LN m ay be m andatory, optional or con- ditional. The data objects them selves contain attributes 1 , w hich m ay be seen as values or detailed properties of the data objects. This hierarchical data m od- el is illustrated in ➔ 4 . S ince the class nam es of LN s and the full nam es of data objects and attributes are standardized, they form ally provide the sem antics of all exchanged values w ithin the scope of IEC 61850. LN s m ay be grouped into logical devices (LD s) w ith non-standardized nam es, and these LD s are im plem ented in servers residing in IED s. The com m on properties of the C om m unication netw orks and system s in substations P art 1: Introduction and overview P art 2: G lossary P art 3: G eneral requirem ents P art 4: S ystem and project m anagem ent P art 5: C om m unication requirem ents for functions and device m odels P art 6: C onfiguration description language for com m unication in electrical substations related IED s P art 7-1: P rinciples and m odels P art 7-2: A bstract com m unication service interface P art 7-3: C om m on data classes P art 7-4: C om patible logical node (LN ) classes and data classes P art 8-1: M apping to M M S and to IS O /IEC 8802-3 P art 9-1: S am pled values over serial unidirectional m ultidrop point-to-point link P art 9-2: S am pled values over IS O 8802-3 P art 10: C onform ance testing 3 T h e p a rts o f th e s ta n d a rd I E C 6 1 8 5 0 E d i ti o n 1 2 T h e s p li t b e tw e e n d a ta m o d e l a n d c o m m u n i c a ti o n s ta c k D a ta m o d e l I S O /O S I s ta c k D o m a i n s u b s ta ti o n : W hat data have to be com m unicated? C o m m u n i c a ti o n te c h n o lo g y : H ow are the data com m unicated? S low changes Fast changes D e fi n i ti o n D ata and services according to the dom ain substation M a p p i n g D ata m odel to the com m unication stack S e le c ti o n IS O /O S I stack from the m ainstream S P L I T ! C o m m u n i c a t i o n A ll application functions, including the data interfaces to the prim ary equipm ent, are broken dow n into the sm allest fea- sible pieces, w hich m ay com m unicate w ith each other and be im plem ent- ed separately in dedicated IED s. 1 0 A B B review special report firm ation”), w hich term inates the control service. P e rfo rm a n c e re q u i re m e n ts The transfer tim e of m essages betw een the sending application (eg, protection function issuing the trip) and the receiv- ing application (breaker function per- form ing the breaker operation) is deter- m ined by the requirem ents of functions that depend on this m essage transfer. A s a protection trip is tim e critical, w ith a w orst case taking around 20 m s, it is allocated to the m ost dem anding trans- fer requirem ent class, w hich m eans 3 m s. The transfer of sam ples using the S V service is also assigned to this require- m ent class to avoid, for exam ple, delays in fault detection by protection. The re- quirem ents have to be fulfilled not only by the IED s but also by the S A system design. The transfer tim e of a G O O S E m essage over a serial link is com pared in ➔ 6 and ➔ 7 w ith the response tim e of a hardw ired contact circuit. To properly analyze the sequence of events in the system and for post-event fault analysis, the events need a tim e stam p w ith an accuracy against real tim e of 1 m s; this incidentally is better than any contact change. H ow ever, tim e syn- chronization for current and voltage sam ples, w hich are needed for differen- tial or distance protection or global pha- sor com parison, requires an accuracy of the order of 1 µs! The 1 m s accuracy lev- el is achieved using the sim ple netw ork tim e protocol (S N TP ) directly over a se- rial com m unication link, w hile one pulse per second (pps) over a separate w ire or fiber achieves the 1 µs tim e synchroniza- tion. In the future, the IEEE 1588 stan- –File transfer: for configuration, disturbance recording or historical data –G O O S E: G O O S E is the acronym for generic object oriented system event and is a service used for the speedy transm ission of tim e critical inform a- tion like status changes, blockings, releases or trips betw een IED s –S am pled value (S V): the S V service quickly transm its a synchronized stream of current and voltage sam - ples for voltages and currents The control service im plem enting the “select before operate w ith enhanced security”m ode is illustrated in ➔ 5 in the context of a sw itch operation: The S ELEC T com m and is issued at the operator’s H M I and com m unicated to the bay control unit represented by the LN C S W I. D epending on the system archi- tecture the S ELEC T com m and is con- firm ed either by the bay controller or the circuit-breaker IED , w hich is represented by the LN XC B R . W hen the operator re- ceives a positive acknow ledgem ent (ie, “S elected”) from the C S W I, he then is- sues an O P ER ATE com m and. O nce per- m ission has been granted, an operation request is sent via the bay controller to the circuit breaker (XC B R ). The execu- tion of the com m and request is positively acknow ledged using the m essage “O p- erated.”A dditional feedback is provided using the reporting service, w hich is initi- ated by the start of the circuit-breaker contact m ovem ent (“S tarted”) and w hen the end position is reached (“N ew posi- tion”). In cases w here a com m and ser- vice w ith enhanced security is chosen, the end result is confirm ed by the com - m and term ination m essage (“C m d con- 5 A n i llu s tra ti o n o f th e c o n tro l s e rv i c e C ontrol circuit for com m ands Indication circuit for breaker position H M I C S W I S elect S elected O perate O perated S tarted N ew position C m d term ination XC B R C ircuit breaker I n d i c a t i o n C o m m a n d s e q u e n c e Enhanced security S e l e c t e d s t a t e 4 H i e ra rc h i c a l d a ta m o d e l Im plem entation G rouping D ata Value P roperties B re a k e r I E D ( B I E D ) N am es not standardized N am es standardized B re a k e r c o n tro lle r X C B R ( c i rc u i t b re a k e r P o s ( p o s i ti o n ) S tVa l ( s ta tu s v a lu e ) Interm ediate-state/off/on/bad-state q ( q u a li ty ) good/invalid/reserved/questionable t ( ti m e s ta m p ) tim e of change P hysical device (IED ) defined as S erver Logical device (LD ) Logical node (LN ) D ata (O bject) A ttribute A ttribute A ttribute G O O S E is the acronym for generic object oriented system event and is a service used for the speedy transm ission of tim e critical infor- m ation like status changes, block- ings, releases or trips betw een IED s. 1 1 T h e c o n c e p t o f I E C 6 1 8 5 0 The station bus m ay be configured in a ring topology w ith ring redundancy, a redundant star for IED s w ith dual port redundancy or any solutions w hich fulfill the requested perform ance and reliability requirem ents. The process bus m ay also adopt a ring or even a star topology, but at the very least one or m ore point-to- point connections. S C L s u p p o rte d e n g i n e e ri n g In order to process data received from IED s, the receiving IED needs to know how this data has been sent; how it has been coded; w hat it m eans in the con- text of the sw itchyard; and the function- ality of the sender. To be able to transfer this inform ation from one tool to another in a standardized w ay, the XM L-based S C L language has been defined. Edition 2 [8] of the standard scheduled for publication in 2010 w ill define proto- cols for the connection of IED s w ith tw o ports to tw o redundant com m unica- tion system s or the form ation of a ring w ith redundant traffic in both ring direc- tions 3 . T h e s ta ti o n a n d p ro c e s s b u s e s The station bus connects the IED s for protection, control and m onitoring (ie, bay units) w ith station level devices (ie, the station com puter w ith H M I and the gatew ay to the netw ork com m unication center (N C C )) using w hatever services are required by the applications. The process bus connects the bay units w ith the sw itchyard devices, and the com - m unication of status inform ation, com - m ands and trips is the sam e as for the station bus ➔ 9 . H ow ever, getting synchronized sam - ples of current and voltage to the rele- vant protection IED s using the S V ser- vice is quite chal- lenging. The conversion of proprietary signals from nonconventional instrum ent transform ers for cur rent and voltage or of the analog values from con- ventional instrum ent transform ers to IEC 61850 telegram s is done using an IED called a m erging unit (M U ). A n M U m erges the 3-phase currents and volt- ages, including the zero-com ponents of one bay high-precision tim e-synchro- nized by definition. The process bus functionality for the sw itchgear is pro- vided by the so-called breaker or sw itch IED s (B IED , S IED ). The free allocation of functions allow s the creation of IED s w ith both B IED and S IED , and M U functional- ities. dard [7] w ill allow high-precision tim e synchronization also directly over Ether- net. T h e c o m m u n i c a ti o n s ta c k a n d m a p p i n g IEC 61850 has selected m ainstream technology for the com m unication stack, ie, a stack structure according to the IS O /O S I layers consisting of Ethernet (layers 1 and 2), TC P /IP (layers 3 and 4) and m anufacturing m essaging specifica- tion, M M S , (layers 5 to 7). The object m odel and its services are m apped to the M M S application layer (layer 7). O nly tim e-critical services, such as S V and G O O S E are m apped directly to the Ethernet 2 link layer (layer 2)➔ 8 . E th e rn e t b u s a rc h i te c tu re s a n d d u a l p o rt re d u n d a n c y IEC 61850 uses Ethernet as the basic com m unication technology, currently w ith a speed of 100 M B it/s at the IED s. S upport of m essage priorities by m an- aged sw itches allow s tim e critical re- quirem ents, such as the 3 m s applica- tion to application transfer tim e, to be m et. Tree and ring topologies are possi- ble w ith sw itches. H ow ever, according to the first edition of the standard, the Ethernet ring topology w ith autom atic reconfiguration in case of link or sw itch failures is the m ost com m on architecture for system s. Tree topologies are not used very often because the sw itch represent- ing the root is a potential single point of failure. It should be noted that in the ring, one sw itch connection has to be alw ays open –creating in effect a kind of tree topology –to avoid endlessly circulating telegram s. The open sw itch connection is autom atically closed if a failure in any of the ring links or in another sw itch cre- ates an unw anted second opening (ie, a tree recovery algorithm ). 6 T ra n s fe r ti m e d e fi n i ti o n w i th h a rd w i re d c o n ta c ts P hysical link (w ire circuit) A pplication function 1 P hysical device P D 1 Transfer tim e t = t a + t b + t c t a t b t c A pplication function 2 P hysical device P D 1 7 T ra n s fe r ti m e d e fi n i ti o n w i th c o m m u n i c a ti o n s ta c k s Transfer tim e t = t a + t b + t c t a t b t c P hysical device P D 1 P hysical device P D 2 C oding in the stack A pplication function 2 A pplication function 1 D ecoding in the stack 8 M a p p i n g to th e s ta c k D ata M odel (D ata and services) Ethernet link layer w ith priority tagging C lient-S erver IP TC P M M S G O O S E S am pled values Ethernet physical layer w ith 100 M B /s 7 6 5 4 3 2 1 I S O / O S I S t a c k L a y e r s Tim e critical services M apping S uch is the potential of IEC 61850 that in the future it is hoped it can be applied right across the pow er system spectrum . 1 2 A B B review special report K la u s -P e te r B ra n d Wo lfg a n g Wi m m e r A B B S ubstation A utom ation B aden, S w itzerland klaus-peter.brand@ ch.abb.com w olfgang.w im m er@ ch.abb.com F o o tn o te s 1 The attributes carry the data values. 2 N ow adays in com m unication technology, m ost efforts and m oney are invested in Ethernet technology. In fact Ethernet is now successfully com peting w ith the traditional field busses. 3 P lease refer to "S eam less redundancy " on page 57 of this issue of ABB Review. R e fe re n c e s [1] B rand, K .P., Lohm ann, V., W im m er, W . (2003) S ubstation A utom ation H andbook. U A C , IS B N 3-85759-951-5. (w w w .uac.ch). [2] IEC 61850 Ed. 1 (2002-2005). C om m unication netw orks and system s in substations. w w w .iec.ch. [3] IEC 61400-25-2. C om m unications for m onitoring and control of w ind pow er plants – P art 25-2: Inform ation m odels for W ind turbines. [4] IEC 61850-7-410. C om m unication netw orks and system s for pow er utility autom ation – P art 7-410: H ydroelectric pow er plants C om m unication for m onitoring and control. [5] IEC 61850-7-420. C om m unication netw orks and system s for pow er utility autom ation – P art 7-420: B asic com m unication structure – D istributed energy resources logical nodes. [6] IEC 81346. Industrial system s, installations and equipm ent and industrial products –S tructuring principles and reference designations. [7] IEEE 1588 –2008. S tandard for a precision clock synchronization protocol for netw orked m easurem ent and control system s. [8] IEC 61850 Ed2 (scheduled for 2010). C om m unication N etw orks and S ystem s for P ow er U tility A utom ation. w w w .iec.ch. [9] B aass, W ., B rand, K .P., G erspach, S ., H erzig, M ., K reuzer, A ., M aeda, T. (2008). Exploiting the IEC 61850 potential for new testing and m aintenance strategies. P aper presented at the m eeting of the International C ouncil on Large Electric S ystem s (C IG R E), P aris, P aper B 5-201. the system . The principles of engineering w ith S C L files are show n in ➔ 1 0 . A s the entire IED data m odel is visible via the com m unication system , including possible configuration and setting para- m eter values, and all this can be de- scribed in S C L, the S C D file is also a m edium usable by other applications in the life-cycle of the system [9], such as the archiving of the system configuration in a standardized form and the transfer of protection param eters to protection system configuration tools. It m ay be used in sim ulation and testing tools or to check the configuration (version) state of the running system against the intend- ed state. W hile these applications are outside the scope of IEC 61850 as a com m unication standard, they are of ad- ditional benefit for the user of the stan- dard. A fu tu re -p ro o f o u tlo o k The long-term value of IEC 61850 for users lies in its object-oriented hierarchi- cal data m odel approach w ith its high- level standardized sem antics and the use of m ainstream com m unication technolo- gy, w hich is dom inated by Ethernet. H ow ever, IEC 61850 is m uch m ore than just a norm al com m unication protocol. S uch is its potential that in the future it is hoped IEC 61850 can be applied right across the pow er system spectrum . A second edition of the standard is scheduled for publication in 2010. It w ill contain m any additional features, such as the support of dual port redundancy for IED s. To allow the exchange of data betw een tools from different m anufacturers, IEC 61850 introduces a basic engineer- ing process: B ased on the system speci- fication and the description of the IED s, the required device types are selected and their form al description, in the form of an IC D file, is loaded into the system configuration tool. The system configura- tion tool then defines the m eaning of IED functions in the context of the sw itchyard by allocating LN s to elem ents of the sw itchyard single-line diagram . The data flow betw een all IED s is then defined, and all IED nam es and com m unication related addresses and param eters are configured. The resulting S C D file is a com prehensive description of the entire system in the context of IEC 61850. This file is then im ported into the device tools of the different IED s to com plete their in- dividual configuration in the context of S IED S IED S IED S IED 9 S ta ti o n a n d p ro c e s s b u s e x a m p le s H M I C u w ires S w itchgear/sw itchyard S IED S IED B IED B IED M U M U S tation level B ay level P rocess level S ta ti o n b u s P ro c e s s b u s N etw ork level P rocess interface S tation gatew ay S tation com puter P rotection C ontrol P rotection & control P rotection C ontrol 1 0 E x a m p le o f e n g i n e e ri n g w i th S C L IED C onfiguration D escription IC D IED C onfiguration D escription IC D IED configuration description (IC D ) D evice capability S ystem specification description (S S D ) S ystem configuration description (S C D ) D evice data D evice data D evice data D evice data D evice data D evice data S C D per IED D evice in the system S ystem docum entation R eusable for testing, m aintenance and extensions S tand-alone device configuration S ystem configuration S ystem and device configuration and data flow “system as built” S ingle-line diagram w ith allocated functions represented by logical nodes (LN s) “system as specified” D evice (IED ) D evice specific tool D e v i c e s e l e c t i o n S ystem configurator The station bus connects the IED s for protection, con- trol and m onitoring w ith station-level devices w hile the process bus con- nects the bay units w ith the sw itchyard devices. 1 3 C o m m o n d e n o m i n a to r M A R T I N O S T E R TA G – With th e a d v e n t o f th e I E C 6 1 8 5 0 s ta n d a rd in 2 0 0 2 , a n d its g ro w in g s u c c e s s in s u b s ta tio n a u to m a tio n a n d la te r in s e v e ra l o th e r in d u s trie s , A B B w a s fa c e d w ith th e c h a lle n g e o f a d a p tin g a v a rie ty o f its p ro d - u c ts to th e n e w te c h n o lo g y in a re la tiv e ly s h o rt tim e . T h is w a s s u c c e s s fu lly a c c o m p lis h e d in p a rt d u e to th e d e v e lo p - m e n t o f c o m m o n c o m p o n e n ts d e s ig n e d fo r u s e in a w id e v a rie ty o f A B B p ro d u c ts . C om m on com ponents have helped AB B adopt the IEC 61850 substation com m u- nication standard in record tim e C om m on denom inator 1 4 A B B review special report A lready in its fourth edition, the guideline serves as a good introduction to the soon-to-be-available second edition of the IEC 61850 standard and defines the stepw ise transition from the first edition to the second. B ased on the principles defined in the application guideline, A B B started to develop reusable com ponents for a variety of products and tools in its portfolio. Tw o im - portant com po- nents are the com - m unication stack and a set of librar- ies that handles IEC 61850 object m odels and con- figurations ➔ 2 . C o m m u n i c a ti o n s ta c k The IEC 61850 com m unication stack ➔ 3 is effectively a piece of softw are that im - plem ents the com m unication services for IEC 61850-8-1 m anufacturing m essage A B B w as heavily involved in the process of creating the IEC 61850 standard. As the stan- dardization w as in progress, and in order to enable a fast tim e-to-m ar- ket, the standard w as already being im - plem ented in products in parallel to the standard's nalization betw een 2002 and 2004. In order to support the standardiza- tion, interoperability tests w ere arranged for these early im plem entations. As AB B believed that the standard w ould be a success, it realized that a w ide variety of products w ould need to support it. The com pany thus decided to im plem ent re- usable com ponents right from the begin- ning. The results of these activities w ere reported back to the IEC organization that used them to im prove the clarity and qual- ity of the standard. In addition, they w ere presented to the public at the IEEE PSR C m eeting in Sun Valley, U SA in 2003 ➔ 1 and at the H annover Fair in April 2004. A t that tim e, A B B outlined a clear step- w ise strategy for the introduction of IEC 61850 into its solutions in its very ow n internal IEC 61850 application guideline. This guideline defines the m an- datory subset of IEC 61850 services that is supported by all A B B devices, it adds additional A B B internal convention, and clarifies and details certain sections w here the standard leaves room for in- terpretation. specification (M M S ) and generic object oriented substation event (G O O S E) serv- ers and clients. M ore im portantly, it hides the nitty-gritty details from the m ore ap- plication oriented research and develop- m ent found in A B B ’s products, thereby allow ing developers to concentrate on providing application value to custom ers. C urrently, the com m unication stack is in- tegrated into m ore than 12 A B B prod- ucts or product fam ilies, w ith a grow ing num ber of host platform s set to follow suit as IEC 61850 continues to be ac- cepted by other industries. The benefits of the IEC 61850 stack include portabili- 2 U s e o f c o m m o n c o m p o n e n ts i n a v a ri e ty o f A B B p ro d u c ts M icroS C A D A P ro / S YS 600 C C O M 600 R EB 500 IEC 61850 com m unication Engineering and testing tools R elion ® 630 series 650 series IED s 670 series IED s C om m on IEC 61850 com ponents: – com m unication stacks – tool libraries 1 I n te ro p e ra b i li ty d e m o n s tra ti o n b e tw e e n m a jo r v e n d o rs a t th e I E E E P S R C m e e ti n g i n S u n Va lle y i n th e U n i te d S ta te s i n 2 0 0 3 C urrently, the IEC 61850 com - m unication stack is integrated into m ore than 12 A B B prod- ucts or product fam ilies, w ith a grow ing num ber of host platform s set to follow suit. R EB 500 Engineering t ti too 1 5 C o m m o n d e n o m i n a to r show s several im portant aspects that need to be observed to successfully capitalize on com ponent develop- m ent➔ 4 . For the upcom ing edition 2 of the IEC 61850 substation com m unication standard, com m on com ponents w ill con- tinue to play an im portant role in sup- porting a m arket-driven, phased upgrade and m igration strategy for A B B ’s product and tool portfolio. C lose links to IEC w orking groups com bined w ith im ple- m entation in parallel to standardization w ill allow A B B to m aintain and strength- en its front-row position in IEC 61850 technology. M a rti n O s te rta g A B B S ubstation A utom ation P roducts B aden, S w itzerland m artin.h.ostertag@ ch.abb.com XM L-based substation configuration lan- guage (S C L) com es into play. In addition, the com m unication stack, w hich is a re- usable com ponent, needs configuration inform ation to enable such com m unica- tion to take place. C onfiguration tools rely on a softw are com ponent that interprets and generates both S C L and stack configuration files. This com ponent allow s the tools to w ork on an object-oriented data m odel rather than parsing and interpreting raw files. In addition, it helps to avoid syntax and se- m antic errors and contributes to the high quality of A B B ’s products. B e n e fi ts o f A B B ’ s a p p ro a c h The m ain benefits of such a com ponent include: The ability to carry out m aintenance and im provem ents in one place, allow ing all products to benefit The uniform im plem entation of functionality, w hich is crucial for interoperability betw een devices from A B B and third-parties D etailed testing and experience in the field. B ecause it is integrated into a variety of products, its functionality is tested w ay beyond w hat can be achieved for product-specific im plem entations. S u c c e s s fa c to rs fo r c o m p o n e n t re u s e A B B ’s experience in the developm ent of com m on com ponents for IEC 61850 ty, and it runs on different real-tim e oper- ating system s as w ell as under W indow s for P C -based products and tools. F i le h a n d li n g a n d o b je c t m o d e li n g Each product to be integrated into an IEC 61850-based system needs to have its functionality defined in a standardized w ay that enables it to com m unicate w ith, and process inform ation from other prod- ucts in the system . This is w here the 3 U s e o f I E C 6 1 8 5 0 s ta c k c o m p o n e n t IEC 61850 IED interface (IA L and direct w rite/read to application) IEC 61850 S ER VER / C LIEN T D B C o n f i g u r a t i o n h a n d l e r S C L - p a r s e r C ontrol handler IEC 61850 m odel H . R eport handler G O O S E handler FileXfer handler S etting handler S ubst. handler M od handler Layer 4 Layer 3 Layer 2 Layer 1 S N TP client Third-party M M S protocol S W IED A pplication/D ata interface IEC 61850-8-1 M M S / IEEE802.3 G O O S E S YN 5200 / S YN 5201 / S YN 5202 4 A s p e c ts th a t n e e d to b e o b s e rv e d to c a p i ta li z e o n c o m p o n e n t d e v e lo p m e n t A lw ays be a step ahead of the products and tools that w ill use the com ponents. In other w ords anticipate upcom ing or future IEC 61850 specific com m unication requirem ents that com ponent users m ight not even be aw are of at the tim e they are im plem ented in the product. Fast reaction and prem ium support during the integration phase of the products research and developm ent. In other w ords, the com ponent research and developm ent team m ust have a very “service provider”oriented m indset in that requests and problem s from product research and developm ent team s m ust be dealt w ith relatively quickly. Version traceability. K eep track of the distributed versions and version dependencies, ie, w hich version of a product contains w hich version of the com ponent. B ackw ard com patibility of the com ponent is very im portant. If substation prim ary equipm ent can have a life expectancy of betw een 30 and 40 years, it is an absolute certainty that the substation autom ation system w ill be extended and upgraded at least once during this tim e. A s a conse- quence, different versions of products and tools need to co-exist in the sam e system . This puts certain requirem ents on the definition of the com ponent’s softw are interfaces and the w ay functionality is im plem ented. The proper clustering of functionality in a w ay that keeps the level of detail com ponent users need to know about IEC 61850 at an appropriate level. This in turn allow s the product engineers to focus m ore on application m odeling and concept developm ent. For the upcom ing edition 2 of the IEC 61850 com - m unication stan- dard, com m on com ponents w ill continue to play an im portant role in supporting a m ar- ket-driven, phased upgrade and m igra- tion strategy for A B B ’s product and tool portfolio. 1 6 A B B review special report A B B product developm ent based on the IEC 61850 standard J A N N E S TA R C K , S T E VE N A . K U N S M A N – S in c e th e p u b lic a tio n o f th e rs t e d itio n in 2 0 0 4 , th e I E C 6 1 8 5 0 c o m m u n ic a tio n s ta n d a rd h a s p ra c tic a lly b e c o m e th e d e -fa c to s ta n d a rd in th e c o n te x t o f s u b s ta tio n a u to m a tio n . A lm o s t fro m th e m o m e n t o f its p u b lic a tio n , in te llig e n t e le c tro n ic d e v ic e s ( I E D s ) s u p p o rtin g I E C 6 1 8 5 0 s ta rte d to a p p e a r o n th e m a rk e t. H o w e v e r, fo r m a n y o f th e s e I E D s , it s o o n b e c a m e c le a r th a t p e rfo rm a n c e a n d fl e x ib ility w e re s a c ri c e d in th e ra c e to g e t to th e m a rk e t rs t. A B B to o k a s o m e w h a t d iffe re n t a p p ro a c h . E x p e rts fro m w ith in th e c o m p a n y p a rtic ip a te d in th e s ta n d a rd iza tio n w o rk fro m d a y o n e , a n d a s it w a s b e in g d e v e lo p e d it w a s d e c id e d to u p g ra d e A B B ’ s R e lio n ® p ro te c tio n a n d c o n tro l p ro d u c t fa m ily to s u p p o rt th e I E C 6 1 8 5 0 s ta n d a rd . B y th e tim e th e s ta n d a rd c a m e in to e x is te n c e , A B B h a d a lre a d y a d o p te d a p h ilo s o p h y o f “ n a tiv e I E C 6 1 8 5 0 im p le m e n ta tio n ” in th a t th e s ta n d a rd is im p le - m e n te d fro m th e s ta rt in n e w p ro d u c t d e v e lo p m e n ts . To d a y, A B B ’ s I E C 6 1 8 5 0 -b a s e d p ro te c tio n a n d c o n tro l p ro d u c ts a re re c o g n ize d a s th e n u m b e r o n e c h o ic e fo r b o th u tility a n d in d u s tria l p o w e r s y s te m s . P ushing the lim its 1 7 P u s h i n g th e li m i ts IEC 61850 im plem entation”philosophy, w hich stated that from then on the stan- dard w ould be im plem ented in new prod- uct developm ents. N a ti v e I E C 6 1 8 5 0 i m p le m e n ta ti o n In a typical IEC 61850 native design, the functionality of the IED m ust consider the entire process, including specification and evaluation, system and device engi- neering, system com m issioning, and op- erations and m aintenance. A n IEC 61850 native IED should provide: –A full set of protection and control data to S A system s, and to other IED s and third-party tools in com pli- ance w ith the defined data m odels and LN s to achieve a high level of interoperability –Fast com m unication and application perform ance, w hich is critical w hen using generic object oriented substa- tion events (G O O S E) peer-to-peer com m unication for distributed protection algorithm s, and com plex station and bay control interlocking schem es over Ethernet in the substa- tion station bus –A dherence to data m odeling and substation configuration language (S C L) inform ation available for system engineering, device configuration, diagnostics and com m issioning tools A s the standard becam e better know n, how ever, engineers realized the benefits it provided presented them w ith an op- portunity to rethink IED platform and ar- chitecture developm ent and introduce new conceptual ideas for substation au- tom ation. A B B w as taking this approach even before the standard’s publication by fully and genuinely im plem enting the standard in m any of its devices, engi- neering and com m issioning tools, and substation autom ation (S A ) system s. In fact, A B B had already adopted a “native W ith the introduction of the IEC 61850 standard, the w orld of substation auto- m ation has taken its big- gest technology leap since the intro- duction of m icroprocessor-based pro- tection and control devices in the early 1980s. A s soon as the standard w as published, intelligent electronic devices (IED s) sup- porting IEC 61850 started to appear on the m arket. The speed at w hich this hap- pened w as achieved by upgrading exist- ing IED platform s w ith an internal or ex- ternal gatew ay serving as a proxy to the IEC 61850 Ethernet-based protocol. B ecause this approach left the IED archi- tecture, internal softw are and tools unchanged, protocol conversion w as required to enable com m unication be- tw een existing IED s and a m odern IEC 61850-based substation. A t the tim e, the IEC 61850 standard w as just one of a num ber of protocols to expose the IED ’s internal inform ation, w hich w as m apped to the IEC 61850 data m odels and logical nodes (LN s). The internal ar- chitecture did not differ from other point or register-based com m unication proto- cols (eg, D N P V3.00 and M O D B U S ). W hile these early im plem entations result- ed in a fast tim e-to-m arket, perform ance and flexibility w ere sacrificed as a result. 1 P h a s e ti m e o v e rc u rre n t ( P T O C ) o v e rc u rre n t fu n c ti o n d e s i g n P T O C L o g i c a l N o d e C la s s D a ta O b je c t E x p la n a ti o n M a n d a to ry / I E D D e s i g n N a m e O p ti o n a l M od M ode M X B eh B ehavior M X H ealth H ealth M X N am eP lt N am e P late M X O pC nt O peration C ounter O O pC ntR s O peration C ounter R eset O S tr S tart M X O p O perate M X Tm A S t A ctive C urve C haracteristic O Tm A C rv O perating C urve Type O X S trVal S tart Value O X Tm M ult Tim e D ial M ultiplier O M inO pTm m s M inim um O perate Tim e O X M axO pTm m s M axim um O perate Tim e O O pD ITm m s O perate D elay Tim e O X TypR sC rv Type of R eset C urve O X R sD ITm m s R eset Tim e D elay O X D irM od D irectional m ode O Even before its publication in 2004, A B B w as extending the lim its of IEC 61850 w ith its full im plem enta- tion of the stan- dard in m any of its devices, tools and substation autom a- tion (S A ) system s. 1 8 A B B review special report this is dependent on the product and in- tended application ➔ 1 . The supported standard data objects are docum ented in the m andatory m odel im plem entation conform ance statem ent (M IC S ) docu- m ent. In the next stage, the standard LN and its selected functionality are m odeled using the S C L, w hich describes the func- tion structures, data objects and data types of an LN ➔ 2 . W ith the defined function structures according to the S C L, it is possible to autom atically generate the skeleton of the application data ac- cess functions (read, w rite) for the IED system softw are. These functions are in- herited and directly linked to the protec- tion algorithm (eg, P TO C ) data in the IED architecture’s core protection and con- trol subsystem . This direct m apping pro- vides a high-perform ance interface to the IED ’s IEC 61850 com m unication stack, w hich in turn m akes the data ac- cessible to the station bus ➔ 3 . N o addi- tional conversion of protection and con- trol data is required to support the com m unication’s architecture and proto- col. S tructures based on LN s can also have a function for settings, w hich are directly visible to the S A system via the com m unication stack. In general, the IEC 61850 standard pro- vides a solid foundation for the design of native IEC 61850 protection and control IED s due to the fact that data m odels have been defined by an international w orking group com posed of experts in fully base the IED ’s functionality on the data m odel and LN s as defined in the standard. A s it now stands, protection and control algorithm s, w hich provide the core IED functionality, are m odeled and im plem ented fully according to the IEC 61850 standard rules. In the new ar- chitecture, the data m odels are support- ed directly in the protection and control functions, m aking the LN data directly accessible from the com m unications services. W ith this approach the data m apping and con- version process is not required, som e- thing that is a key factor in IED per- form ance. IED data are therefore di- rectly available w ith- out tim e-consum - ing additional pro - cessing. W hen a new pro- tection function, such as overcur- rent protection, is im plem ented, the standard phase tim e overcurrent (P TO C ) LN -class definition is the foundation for m odeling the protection algorithm . D epending on product and application requirem ents, all m andatory and select- ed optional attributes of the LN -class are used in the function design. The IEC 61850 standard requires that the m andatory data objects m ust exist in the data m odel of the device. The optional parts are only used w hen applicable, and –Ease of adaptation and be future proof to evolving technologies enabled by Ethernet and IEC 61850, for exam ple, utilizing IEC 61850-9-2 sam pled values and m icrosecond-level tim e synchroni- zation accuracy via IEEE 1588 A B B ’s R elion ® protection and control product fam ily w as one of the first to un- dergo the IEC 61850 transform ation. The products required a com pletely new plat- form architecture that w ould integrate com m unication services and data repre- sentation into the core protection and control applications. This developm ent w as carried out in parallel w ith the devel- opm ent of the IEC 61850 standard (pre- 2004) to ensure that the future A B B R elion fam ily w as designed from the be- ginning to support IEC 61850. T ra n s fo rm i n g th e R e li o n I E D s O ne of the key factors that led to suc- cessful product transform ations w as to 2 V i s u a li z a ti o n o f th e s u b s ta ti o n c o n fi g u ra ti o n la n g u a g e ( S C L ) 3 D a ta s tru c tu re i n a P T O C fu n c ti o n A B B ’s R elion ® protection and control product fam ily w as one of the first to undergo the IEC 61850 transform ation, a developm ent that w as carried out in parallel w ith the devel- opm ent of the standard. 1 9 P u s h i n g th e li m i ts ticular LN structure. A fter a protection task cycle com pletes, the IED process- ing subsystem perform s a signal com - parison to identify new data in the IEC 61850 connected datasets. In the IEC 61850 data m odel, m ost data- change driven activities are based on the datasets, for exam ple, event reporting and G O O S E data publishing. The IED change detector identifies changes in the datasets and if a new value is detect- ed, the dataset and its connected func- tionality are triggered. In an IED using G O O S E, the internal high-priority sub- system executing the G O O S E function is triggered. S ubsequently, the m odified data is sent as quickly as possible through the IED com m unication interface to the S A system station bus using a G O O S E m ulticast m essage. G O O S E m ulticast m essages are unsolicited broadcasts w hich do not require any cy- clical data polling m echanism . D ata structures used in G O O S E include direct access to the IED internal database, and because the internal data m odel exactly m atches the IEC 61850 standard, no data conversions are required ➔ 4 . In the sam e w ay, the IED ’s IEC 61850 na- tive design yields high-perform ance sub- scribing G O O S E datasets from other IED s in the local sub-netw ork. A s G O O S E m essages are processed in the data link layer in the Ethernet stack, this does not require additional processing through the TC P and IP layers. This type of Ethernet com m unication is very fast since the data is retrieved directly from the IED com m u- nications hardw are interface. The IED ’s G O O S E processing capabilities can de- code the m essage in less than 1 m s and the field. W ith standard-based data m od- eling, faster developm ent of IED applica- tion functions and com m unication inter- faces can be obtained. The im provem ents are due to the LN structures, w hich are inherent in the protection application. This therefore m akes data access from the IEC 61850 based S A system to the IED 's internal protection and control al- gorithm s very com putationally efficient and elim inates the need for tim e-con- sum ing protocol conversion processing. T h e p e rfo rm a n c e o f a n a ti v e R e li o n I E D IED architectures designed to support IEC 61850 from the start need to ensure that the delay in com m unicating control signals, analog values and other tim e critical data betw een the process and the IED s is as sm all as possible. In tradi- tional IED s, the binary and analog signals w ere processed by the IED hardw are I/O subsystem . In IEC 61850-based archi- tectures, conventional w iring has been elim inated and these signals are trans- m itted and received via the com m unica- tions interface. Thus, the com m unication interface in the new IEC 61850-based IED s m ust be very efficient at processing the com m unication data. The fast G O O S E perform ance of a R elion IED is critical in a native IEC 61850 im - plem entation to allow control signal pro- cessing as if it w ere a traditional hard- w ired IED . D uring IED algorithm execution or task cycle, the data values of a pro- tection function (eg, the protection start in P TO C ) can change if an overcurrent is detected on a feeder, and this in turn up- dates the database supporting the par- In IEC 61850-based archi tectures, con- ventional w iring has been elim inat- ed and binary and analog signals are transm itted and received via the com m unications interface. 4 G O O S E d a ta a n d m e s s a g e h a n d li n g IED D B P rotection task G O O SE R X task C hange detector G O O S E TX task Physical I/O S tation bus P TO C M od ctlVal B eh operTm H ealth stVal N am eP lt q Loc stS eld O pC ntR s pulseC onfig P os R R EC C S W I IED 6 I E C 6 1 8 5 0 e v e n t h a n d li n g IED D B P rotection task IEC 61850 M M S stack C hange detector Physical I/O P TO C M od ctlVal B eh operTm H ealth stVal N am eP lt q Loc stS eld O pC ntR s pulseC onfig P os R R EC C S W I IED 5 I E C 6 1 8 5 0 h a n d li n g i n c a s e o f a s e p a ra te c o m m u n i c a ti o n s m o d u le P rotection task C hange detector P hysical I/O IED Internal bus M ain C om m S tation bus Internal bus IEC 61850 P TO C M od ctlVal B eh operTm H ealth stVal N am eP lt q Loc stS eld O pC ntR s pulseC onfig P os R R EC C S W I IED 2 0 A B B review special report are defined and used in the IED tool and connectivity packages, and are available for the user w hen an IEC 61850 configu- ration (S C L) is exported using the IED tool. In the new IED architecture, traditional com m unication protocols, such as M od- bus, IEC 60870-5-103 and D N P 3.0 are m apped from the IEC 61850-based data m odel and event datasets. The conve- nience of protocol m apping stem s from the fact that IEC 61850 includes m ost of the different data and service types re- quired for legacy protocols. A com pari- son of legacy protocols and IEC 61850 typically show s that legacy protocols have a subset of services and data types available. M any custom ers prefer to use legacy protocols and the internal archi- tecture of an IED m ust be ready to sup- port m ultiple protocols. IEC 61850, how - ever, is the preferred superset in term s of functionality and services. S y s te m e n g i n e e ri n g IED s belonging to the R elion product fam ily are configured according to the rules defined in the IEC 61850 standard. The configuration is based on library in- stallable client driver (IC D ) files available in the IED connectivity packages w here these library files include the IED ’s data m odel. In the top-dow n engineering pro- cess, the system integrator selects the appropriate library IC D files representing the R elion IED types and builds the sys- tem configuration description (S C D ) ac- cording to the substation design. In this phase, the substation configuration al- ready includes all IED s, the single-line diagram , the G O O S E links betw een the devices and the event definitions. The S C D file is im ported to the IED tool w here the IED s are param eterized and config- ured according to the application/pow er system specifications ➔ 7 . In sm all and sim ple IEC 61850 based substations, the system engineering of the substation autom ation system can be done using a bottom -up process. The w orkflow starts from the IED tool, w hich creates the set of IED s and exports the initial S C D file to the system configura- tion tool. U sing connectivity packages, the IED tool exports the S C D file, includ- ing a default single-line diagram and datasets for event reporting. In m any cases, these values, as such, fit custom - er specifications. In the system configu- its associated tim estam p and quality at- tributes are stored in an internal event queue by the IED ’s change detector. A t the sam e tim e, the IED ’s com m unication interface is triggered and starts sending queued events to clients (eg, the gate- w ay or station H M I) on the station bus ➔ 6 . A s internal data m odels and stack data structures are based on the sam e IEC 61850 data m odel, there is no need to carry out any additional data processing. A B B has created an internal IEC 61850 application guideline that defines the ap- propriate default dataset nam es and uses; for exam ple, S tatN rm l for protec- tion events and S tatU rg for prim ary equipm ent value changes. In this w ay, different IED s in the R elion fam ily have sim ilar properties and are easier to con- figure in the S A system . D efault values deliver only the m odified subscribed G O O S E data to the IED ’s internal data- base, w hich m akes it im m ediately acces- sible to the next execution of the protec- tion and control algorithm s. A “put” operation is a single data value copy from a G O O S E fram e to the internal LN structure database ➔ 4 . N o conversion is required as the data in both the IED da- tabase and incom ing G O O S E m essage com ply w ith IEC 61850 data types. The next application execution checks for new input values and processes them accordingly. If G O O S E w as based on a non-native IEC 61850 im plem entation, a conver- sion from an internal data m odel to an IEC 61850 data m odel w ould be needed. It w ould therefore be difficult to achieve the perform ance classes for protec- tion com m unication as stated in the IEC 61850 standard. In som e architec- tures, the processing of horizontal com - m unication utilizes a different processor on a separate IED com m unication card or an external gatew ay, w hich w ould m ake the perform ance and configuration even m ore challenging ➔ 5 . R eporting events to S C A D A system s using standard buffered or unbuffered reporting services is based on the sam e m echanism that is im plem ented to de- tect G O O S E data changes. W hen a change of data is activated by an appli- cation, for exam ple, a protection start signal in P TO C , the new data value and 7 S y s te m e n g i n e e ri n g w o rk flo w IED lib IC D Engineering w orkplace S C D C ID S ystem configurator S ubstation gatew ay IED IED IED File transfer and param etrization w ith IEC 61850 services IED C apabilities (LN , D O ,…) A ssociations, relation to single line, preconfigured reports, G O O S E S ystem specification (S ingle line, IED s,…) File transfer local File transfer rem ote E n g i n e e ri n g e n v i ro n m e n t S A s y s te m IED configurator The configuration of IED s belonging to the R elion prod- uct fam ily is based on IC D files avail- able in the IED connectivity pack- ages. 2 1 P u s h i n g th e li m i ts therefore capable of interoperating w ith other system s offering IED protocol ser- vices and w hich have S C L files exported from the IED tool. A typical IEC 61850 certificate from K EM A is show n in ➔ 8 . To date the IEC 61850 standard confor- m ance test does not test IED perfor- m ance. H ow ever, part 5 of the standard defines, for exam ple, a perform ance class P 1, type 1A “Trip”for protection purposes using horizontal G O O S E com - m unication. A ccording to this definition, data exchange tim es betw een IED s m ust not exceed 10 m s in distribution autom a- tion applications. Tw o IED s, the R EF630 and R EF615, both m em bers of the R elion fam ily, w ere in- stalled in A B B ’s U niG ear m edium -voltage sw itchgear cubicles and tested accord- ing to the procedures stated in the IEC 62271-3 standard 2 ➔ 9 . This stan- dard, applicable to sw itchgear and con- trol gear, specifies equipm ent for digital com m unication w ith other parts of the substation and its im pact on testing. S pecifically, the standard defines perfor- m ance test procedures w ith reference to the IEC 61850 perform ance classes and the requirem ents w hich the IED m ust ful- fill for these applications.✎ The test results m ore than proved the concept. In fact the functional and per- form ance test results have been nothing short of im pressive. The R elion IED s ful- filled the perform ance class defined by ration tool, the system engineer can add G O O S E links and if required, custom ize the details of the single-line diagram and event datasets. The system engineer ex- ports the com pleted S C D file back to the relay setting tool w here the IED 's appli- cation configuration is finalized. In both top-dow n and bottom -up system engineering processes, the final result is an S C D file w hich is needed for the con- figuration of substation S C A D A system s and gatew ays. The substation section of the S C D file can be used as an inform a- tion source to create the substation sin- gle-line diagram , w hich in turn m inim izes any additional w ork needed for the de- sign of the substation’s graphical dia- gram . In this w ay, the S A system greatly benefits from the self-descriptive feature of the IEC 61850 defined S C L. Te s ti n g a n d u s i n g R e li o n I E D s The capability of the native IEC 61850 im plem entation and the IED design have been thoroughly tested as part of the de- velopm ent validation –as have products already on the m arket –at the A B B U C A level B certified S ystem Verification test C enter (S VC ) 1 . The m ost im portant test is the basic IEC 61850 conform ance test. A ll R elion IED s have been tested and certified according to the procedures de- fined in part 10 of the IEC 61850 stan- dard. For end users and m anufacturers, the certificate states that no nonconfor- m ities to the standard have been found in the behavior of the IED s. The IED s are All R elion IED s have been tested and certi ed according to the IEC 61850 standard; for end users and m anu- facturers, this m eans that no non- conform ities to the standard have been found in the behav- ior of the IED s. 8 A K E M A c e rti fi c a te 9 I E D m e m b e rs o f th e R e li o n fa m i ly a n d th e i r i n s ta lla ti o n i n A B B 's U n i G e a r M V s w i tc h g e a r 2 2 A B B review special report K e e p p u s h i n g th e li m i ts The introduction of the IEC 61850 stan- dard and its achievem ent in enabling device level interoperability is consid- ered a m ajor advancem ent over legacy and proprietary protocols. A B B ’s native IEC 61850 R elion product fam ily im ple- m entation dem onstrates that interopera- bility is only one goal that can be realized by this standard. The product architec- tures provide increased value and high perform ance, and are capable of m eet- ing the m ost dem anding application requirem ents. A nother m ain goal of IEC 61850 is that it future proof’s a com - pany’s investm ent. This can only be done w hen the products m eet tom orrow ’s an- ticipated perform ance requirem ent and engineering tools, and processes can be easily extended in future station expan- sion. A B B continues to explore advanced applications and engineering im prove- m ents. Its G O O S E perform ance is best in its class and the goal is to continue to push the benefits of IEC 61850 w ell beyond w hat is now possible. J a n n e S ta rc k A B B D istribution A utom ation Vaasa, Finland janne.starck@ fi.abb.com S te v e n A . K u n s m a n A B B S ubstation A utom ation R aleigh, U nited S tates steven.a.kunsm an@ us.abb.com R e fe re n c e s [1] IEC 61850 (2003). C om m unication netw orks and system s in substations, International S tandard. [2] IEC 62271 (2006). H igh-voltage sw itchgear and controlgear. [3] H akala-R anta, A ., R intam aki, O ., S tarck, J. (2009). U tilizing P ossibilities of IEC 61850 and G O O S E. C IR ED , P rague. F o o tn o te s 1 The U C A users group m aintains the IEC 61850 standard and defines different levels of certified IEC 61850 test centers. Independent labs are generally classed as level A test centers w hile m anufacturer test labs, like A B B S VC , are certified as level B test centers. For m ore inform ation on S VC , please also read "Verified and validated" on pages 23–28 of this ABB Review S pecial R eport 2 The tests w ere w itnessed and reported by K EM A . S C L. The com plete topology of both the prim ary and secondary netw ork of a sub- station is described in the S C D file. This inform ation source can be used to auto- m atically generate graphical diagram s on the station H M I, such as the com m uni- cation netw ork overview including super- vision data and the station single-line di- agram . W hile this reduces the engineering w ork needed, it also im proves quality w ith respect to consistency because of the single inform ation source being used. Furtherm ore, m aintenance and extension w ork becom es m ore efficient and the efforts needed for testing can be auto- m ated or reduced. M oreover, based on the static inform ation available in the S C D file together w ith the online status inform ation from the substation IED s, new types of applications can be devel- oped. O ne exam ple of a new application al- ready im plem ented in today’s products, and w hich is very beneficial to operators, is dynam ic busbar coloring. The prim ary netw ork layout (ie, conducting equip- m ent, objects) is know n from the S C D file. Together w ith the actual positions and m easurem ents reported from the IED s, all inform ation is available to per- form this task. A m ore com plex function or application is station interlocking. A lgorithm s can be im plem ented to dynam ically adapt the interlocking rules based on the current substation netw ork topology. A gain, the required inform ation to perform this to- pology-based interlocking can be re- trieved from the S C D file and the online data provided by the IED s. A nd last but not least, the IEC 61850 LN s allow the im plem entation of distrib- uted functions, w hich w ill no doubt lead to new applications in the not too distant future. IEC 61850-5 for protection applications using G O O S E. In addition, they show ed that the signaling betw een devices using G O O S E w as faster than w ith traditional hardw ired signals ➔ 1 0 . The perform ance capability of the R elion product fam ily allow s the custom er to fully exploit the benefits of the IEC 61850 standard in S A system s and sm art grid solutions. B ased on a native im plem en- tation, the R elion product technology is w ell prepared for tom orrow 's challenges. This surely puts A B B 's solution in a pre- em inent position am ong com petitors w orldw ide. S A a p p li c a ti o n p e rs p e c ti v e s fo r I E C 6 1 8 5 0 tra n s m i s s i o n a p p li c a ti o n s The benefits of IEC 61850 over tradition- al com m unication protocols are not strictly lim ited to IED s, open infrastruc- tures and device interoperability in m ulti- vendor system s. To explain further, m ajor features of the standard that are used include the self- describing IED s and the standardized 1 0 I E C 6 2 2 7 1 -3 p e rfo rm a n c e te s t re s u lts P rotection blocking data exchange tim e betw een R elion ® IED s using hard w ired signals (m ax) including protection activation tim e 32 m s P rotection blocking data exchange tim e betw een R elion ® IED s using IEC 61850 G O O S E (m ax) including protection activation tim e 16 m s S ignal transfer tim e betw een R elion ® IED s using hard w ired signals (m ax) 24 m s S ignal transfer tim e betw een R elion ® IED s using IEC 61850 G O O S E (m ax) 8 m s A B B continues to explore advanced applications and engineering im - provem ents and the goal is to continue to push the benefits of IEC 61850 w ell beyond w hat is now possible. 2 3 Ve ri fi e d a n d v a li d a te d S T E P H A N G E R S P A C H , P E T E R WE B E R – Wh e n th e I E C 6 1 8 5 0 sta n d a rd wa s in tro d u c e d , A B B n o t o n ly im p le m e n te d it in its p ro d u c t p o rtfo lio , b u t a lso e sta b lish e d a syste m ve ri c a tio n a n d va lid a tio n c e n te r ( S VC ) , to ve rify c o rre c t im p le m e n ta tio n . I n th is te st c e n te r, e a c h a n d e ve ry p ro d u c t, syste m c o m p o n e n t, a p p lic a tio n a n d to o l is te ste d in a re a l-life syste m e n viro n m e n t to d e m o n stra te its sp e c i e d fu n c tio n a lity a n d p e rfo rm a n c e . C o m p le te syste m s a re ve ri e d to e n su re th a t th e y fu lly m e e t th e re q u ire - m e n ts in te rm s o f c o m m u n ic a tio n , in te g ra tio n , fu n c tio n a lity, se c u rity a n d p e rfo rm a n c e . A B B has its ow n system verification and vaildation center Verified and validated 2 4 A B B review special report The editor of the Testing Q uality A ssur- ance P rogram (Q A P ) w as also the editor of P art 10, “Testing R equirem ents”, of the IEC 61850 docum ent. Furtherm ore, m any m em bers of TC 57/W G 10 are on U C A Iug’s Technical S ubcom m ittee for the R esolution of 61850 Issues (Tissues). The group w orks closely w ith standards organizations to support technology transfer, resolution of issues and assists users in the testing and im plem entation of products. O ne m ajor focus of U C A I- ug’s charter is the Testing Q uality A ssur- ance P rogram (Q A P ). A re c o g n i z e d I E C 6 1 8 5 0 c o n fo rm a n c e te s t c e n te r U C A Iug has qualified S VC as an IEC 61850 test facility and com petence centre. S VC is thereby officially qualified to test and certify the IEC 61850 confor- m ity of products and confer the users’ group label to them . S VC is represented on U C A’s IEC 61850 testing subcom m ittee. This strengthens the center’s ability to support upcom ing IEC 61850 test procedures and keeps it inform ed about U C A - and IEC -driven changes regarding IEC 61850 testing. Validation m eans: –Is the right product being built? –Is it m eeting the operational need in the designated environm ent? Tests perform ed as part of S VC valida- tion focus on the behavior of the product in the specified system environm ent. B oth verification and validation are nec- essary throughout the product-develop- m ent cycle ➔ 2 . U C A I u g The U C A 1 International U sers G roup (U C A Iug) is a not-for-profit consortium of leading utilities and their supplier com pa- nies. U C A Iug is dedicated to prom oting the integration and interoperability of electric/gas/w ater utility system s through technology based on international stan- dards. The group is an international or- ganization and strongly supports open standards and the free exchange of in- form ation. O ne activity of U C A Iug is the provision of a forum in w hich m em bers coordinate their efforts in relation to the various technical com m ittees. A lthough the group does not w rite standards as such, its activities affect the definition of standards as w ell as the im plem entation of testing and product certification pro- gram s. O ne focus has been on the “C om - m unication N etw orks and S ystem s in S ubstations" section of IEC 61850. U C A Iug com plem ents the activities of international standards organizations. For exam ple, U C A Iug w orks closely w ith IEC . The convener of IEC TC 57/W G 10 (IEC 61850) is on several U C A Iug com - m ittees and is an advisor to their board. T he purpose and scope of S VC is sum m arized in ➔ 1 . The cen- ter does not only test individu- al devices, but also tests their integration into larger system s and fur- therm ore provides support and under- standing of the standard, leading to its im proved integration and im plem enta- tion. Ve ri fi c a ti o n v e rs u s v a li d a ti o n The relative concepts of verification and validation are som etim es a cause of con- fusion. Verification m eans: –Is the product being built according to the original specification? –A re the specified requirem ents being m et? Verification testing should thus be about the product’s conform ance to the origi- nal specification. In S VC verification, all tests perform ed assure the product accords w ith the de- fined substation autom ation require- m ents. These requirem ents are defined and review ed by a group of experts ap- proxim ately once per year and have to be im plem ented in each A B B product. 1 A B B ’ s s y s te m v e ri fi c a ti o n a n d v a li d a ti o n c e n te r ( S VC ) A ll actions of the S VC are focused on the follow ing targets: – Ensure a com m on understanding for the system integration of products – Ensure a com m on understanding for the engineering process. – A im at a consistent philosophy w ithin A B B system s and products – Identify and initiate the closing of gaps betw een system requirem ents and product features – Im prove the quality of the system solution in architecture, integration and perform ance – D ecrease dem and for specialized expertise w ithin a custom er system project – B uild up integral know how in testing and system integration of third party products – R educe cost and execution tim e of custom er projects The S VC ’s purpose is to ensure the high quality of A B B ’s system autom ation system solutions and provide a platform for the exchange of experience betw een IEC 61850 experts w ithin A B B . Each and every product, system com ponent, appli- cation and tool is tested in a real-life system environ- m ent to dem on- strate its specified functionality and perform ance. F o o tn o te s 1 U C A : U tility C om m unications A rchitecture 2 5 Ve ri fi e d a n d v a li d a te d The fact that standard products from dif- ferent suppliers or different products from the sam e supplier conform to the standard is in itself no guarantee for their interoperability. The reason for this is that com m unication profiles can differ. A com m unication profile defines the m andatory subset of a standard con- sisting of the selected options that are im plem ented. Thus various pro- files from different products m ay con- form to the stan- dard but m ay still not be totally in- teroperable ➔ 3 . It is the responsi- bility of the system integrator to check the interoperability of tw o or m ore products. The require- m ents for this are based on the confor- m ance statem ents of the different prod- ucts and the system functionality B e y o n d c o n fo rm a n c e te s ti n g : s y s te m v e ri fi c a ti o n a n d v a li d a ti o n O nce a product has passed conform ance testing, it can be accepted for form al system verification and validation. I n te ro p e ra b i li ty Interoperability testing is neither part of the scope of the standard nor is it tested by all U C A Iug accredited test centers or in all procedures. H ow ever, the verifica- tion of conform ance is a very im portant m ilestone. 2 B o th v e ri fi c a ti o n a n d v a li d a ti o n a re p a rt o f th e p ro d u c t-d e v e lo p m e n t c y c le . S ystem unit system s (S A S ) S ystem unit products (S A P ) S A products w ith IEC 61850 ready for gate 5 –S ystem solutions (C ontrol, P rotection, S A S ) –S ystem engineering tools and processes –D efinition of system functionality S VC S ystem integration, verification and validation 3 T h e fa c t th a t p ro d u c ts c o n fo rm to th e s ta n - d a rd d o e s n o t g u a ra n te e in te ro p e ra b ility. C om pany B profile C om pany C profile Interoperable profile IEC 61850 C om pany A profile Various profiles from different products m ay conform to the standard but m ay still not be totally interoperable. A n interoperability test looks at the dynam ic interaction of at least tw o IED s in a sub- station autom ation system covering (as far as possible) all potential configurations. Verification and validation –Engineering –Functionality –P erform ance –R edundancy –S ecurity B ased on “m ost com m on use” Interoperatbility –A B B -products –3 rd party products in A B B system s –Tools IEC 61850 conform ance –IED ’s –Tools 2 6 A B B review special report required. For exam ple, one vendor m ight im plem ent only G O O S E 2 and a second vendor m ight im plem ent only G S S E 3 . B oth devices w ould pass conform ance tests but w ould not be able to interoper- ate. A n interoperability test looks at the dy- nam ic interaction of at least tw o IED s in a substation autom ation system (S A S ) covering (as far as possible) all potential configurations. This is especially im por- tant for their interaction in executing dis- tributed functions. Furtherm ore, it per- m its the verification of the perform ance of services provided by com m unication equipm ent such as sw itches (including delays caused). This test m ust be per- form ed independently of specific projects as a kind of type test for the system . S uch testing w ill reduce the risks for cus- tom er projects considerably. The interop- erabillity of the different configuration and engineering tools (based on S C L 4 C o n fi g u ra ti o n o f th e S VC s y s te m The goal of IEC 61850 is the interoperability of IED s in S A S s. The system test should therefore be part of R &D and conform ance testing. 132 kV voltage level E1 sub transm ission 245 kV voltage level D 1 transm ission S VC s y s te m c o n fi g u ra ti o n – o v e rv i e w s i n g le li n e s 33 kV voltage level H 1 distribution 11 kV voltage level H 1 distribution A ll c o n fi g u ra ti o n s a re b a s e d o n s y s te m u n i t s o lu ti o n s to e n s u re " m o s t c o m m o n u s e " o f th e I E D s /S A S and XM L) is also im porant here. A s a side effect, this testing also perm its the system configuration tool and its inter- face w ith the product tools to be veri- fied. Te s t s e tu p , S VC e n v i ro n m e n t The S VC installation represents all areas of A B B ’s system -autom ation activities from distribution to transm ission appli- cations (245 kV, 132 kV, 33 kV, 11 kV). A ll configurations are based on system -unit solutions to ensure ”m ost com m on use“ of the IED s/S A S . The prim ary process is com pletely sim u- lated by process-sim ulation equipm ent. The related single-line diagram s are show n in ➔ 4 . F ro m p ro d u c t to li fe c y c le te s ti n g o f S A s y s te m s It is not possible to consider the lifecycle of any S A S w ithout taking into account the lifecycles of all integrated products. The process of creating a substation auto m ation system involves num erous tests, from the developm ent and produc- tion of an individual IED to the com ple- tion of the system . Testing im proves the quality and reduces costly risks both for the supplier and the users. F o o tn o te s 2 G O O S E: G eneric O bject O riented S ubstation Event, A data-set form at perm itting the exchange of a w ide range of possible com m on data. 3 G S S E: G eneric S ubstation S tatus Event. In contrast to G O O S E this supports only a fixed data structure. 2 7 Ve ri fi e d a n d v a li d a te d 5 Te s ti n g s e q u e n c e fo r p ro d u c t te s ti n g b y R & D , p e rfo rm e d i n d e p e n d e n tly o f c u s to m e r p ro je c t R & D te s ti n g s e q u e n c e D evice type test Integration test S ystem test 7 Te s ti n g s e q u e n c e fo r c u s to m e r p ro je c t C u s to m e r p ro je c t te s ti n g s e q u e n c e Factory test FAT S ite test S AT 6 O v e rv i e w o f R & D te s ti n g s e q u e n c e D evice Type Test Integration test S ystem test M anufac- turing Test Test related to P re-condition Executed tests Function and type tests are perform ed continuously by the R &D of the m anufacturer The product w ith its functions is tested as stand-alone unit (“w hite box”) IEC 61850 conform ance tests Tests are perform ed in a sm all, w ell-defined and norm ally fixed IEC 61850 test system Test of IEC 61850 com m unications and verification of tools including com m issioning and application engineering aspects Focus on the products and its interfaces to the rest of the system (“B lack box”) IED configuration tool w ill be tested also regarding IEC 61850 aspects like generation and exchange of S C L Files S W has dedicated m anufacturing test S pecification and developm ent of new functions … … based on an existing platform or … based on a new platform D evice type tests are finalized successfully Integration tests are finalized successfully A ll tests up to system test finalized successfully C learance for Integration Test C learance for S ystem Test R elease for use in custom er projects P roduct available for custom er projects P roduct P roduct S ystem P roduct R esult –Verification of products w ith a clear focus on IEC 61850 system aspects –Tools and their interaction in the engineering process (exchange IEC 61850 S C L files) –Verification of the system under norm al operation, avalanche and fault conditions (evaluation IEC 61850 system perform ance) –S ystem -security testing. The base for reliable in-house testing is the quality system of the m anufacturer and supplier according to ISO 9001/9002 (as far as applicable). The life-cycle testing sequence can be divided into tw o parts: –Testing independent of the custom er- specific project, handled entirely by the R &D organization. –Testing of configurations specific to the custom er project, com pletely handled by the system supplier or system integrator in cooperation w ith the end-user. Te s ti n g i n d e p e n d e n t o f th e c u s to m e r-s p e c i fi c p ro je c t The test sequence for the standalone product (w hich can be the device or the IED ) starts w ith the device’s type test and ends w ith its integration test➔ 5 . The conform ance test is the type test relating to standards such as IEC 61850. The successful passing of type tests is the prerequisite to begin integration testing. Integration testing involves testing the new product in a sm all and fixed test system . Type tests and integration tests are perform ed (as a m inim um ) by the product supplier and (if applicable and requested) by an independent test au- thority. N orm ally, the conform ance of the IED is confirm ed by the issuing of a cer- tificate. In addition, routine tests or m an- ufacturing tests perform ed in the pro- duction chain ensure a constant quality of delivered devices. The goal of IEC 61850 is the interopera- bility of IED s in S A S s. Therefore, the sys- S everal hundred IED s can be sim u- lated in the S VC , helping identify the lim itations of S A S ystem s. 2 8 A B B review special report dures for all labs in accordance w ith IEC 61850-10 and the U C A Q uality A s- surance P rogram (Level A independent lab, Level B m anufacturer’s lab). The S VC is an active m em ber of U C A inter national users group and the IEC 61850 testing subcom m ittee. In 2007, S VC extended the test centre to fulfill new upcom ing requirem ents. B e- sides the verification and validation of A B B products against IEC 61850-8-1, activities w ere extended to third party IED ’s, redundancy concepts, and IEC 61850-9-2. Today the S VC test system com prises a considerable quantity of relays from A B B as w ell as from several other m anufactur- ers. In addition, several hundred IED s can be sim ulated, helping identify the lim itations of S A S ystem s in term s of ar- chitecture, engineering processes, engi- neering tools, system functionality, sys- tem security and perform ance. S VC helps ensure the high quality of A B B ’s IEC 61850 offerings through its verification and validation capabilities and provide a platform for the exchange of experience betw een IEC 61850 ex- perts w ithin A B B . S VC actively influences further IEC 61850 developm ents both w ithin and outside A B B . S te p h a n G e rs p a c h P e te r We b e r A B B S ubstation A utom ation S ystem s B aden, S w itzerland stephan.gerspach@ ch.abb.com peter.w eber@ ch.abb.com site tests are carried out to prepare the system for the site acceptance test (S AT). The testing sequence for custom er proj- ects consists of project-related tests, based on the specification for the system ordered. S uch tests are perform ed by the system supplier or system integrator and w itnessed by the custom er. These tests confirm that the delivered individual S A S is running as specified ➔ 8 . S u c c e s s fu l o p e ra ti o n o f th e te s t c e n te r Follow ing the planning and build-up phase, by m id 2005, S VC w as ready for operation. In 2006, the center w as quali- fied by the U C A Iug for use as an IEC 61850 test facility and com petence centre. S VC w as the first m anufacturer’s test lab in the w orld to earn this level of qualification. It m eets the high quality levels set out for com m on test proce- tem test should also be part of the R &D testing sequence and conform ance test- ing. H ow ever, as explained above, both the content of IEC 61850-10 and the de- tailed test procedures defined by the U C A Iug only focus on IED (single prod- uct) testing. Today’s conform ance certifi- cates are thus no guarantee for interop- erability from a system perspective ➔ 6 . In sum m ary: S VC takes care of that part of system testing not covered by the pre- vious quality assurance steps. Te s ti n g o f c o n fi g u ra ti o n s s p e c i fi c to c u s to m e r-p ro je c ts The custom er-project testing sequence ➔ 7 starts w ith the factory test. This is a proj- ect-related test that prepares the cus- tom ized system for the factory accep- tance test (FAT). Follow ing the installation, 8 O v e rv i e w o f te s ti n g s e q u e n c e fo r c u s to m e r p ro je c t Factory test Factory acceptance test (FAT) S ite test S ite acceptance test (S AT) Test related to P re-condition Executed tests C onfiguration of the full system P roject assem bled and pre-tested especially regarding project specific parts; parts not available in the factory are sim ulated on IEC 61850 netw ork. Tests perform ed according to the agreed test plan. S ystem test w itnessed by the custom er C om plete system goes into operation, fully functional including all connections to sw itchgear and rem ote system s and w ork places Last adaptations if needed C om plete system w ill be w itnessed by the custom er. A ll tests up to system test finalized successfully and products available for projects A ll factory tests are finalized successfully FAT finalized successfully. A ll system com ponents are installed. S ystem com m issioned on-site The substation autom ation system is running as specified C learance for shipping, com m issioning and S AT The com plete substation autom ation system is running as specified System handed over to the custom er, incl fi nal SC D le! C ustom er project C ustom er project C ustom er project C ustom er project R esult 2 9 A te s ti n g e n v i ro n m e n t T E T S U J I M A E D A – T h e te stin g a n d c o m m issio n in g o f I E C 6 1 8 5 0 -b a se d su b sta tio n a u to m a tio n syste m s in tro - d u c e n e w c h a lle n g e s a n d d e m a n d s fo r a d va n c e d so ftwa re a p p lic a tio n s. A B B re c o g n ize d th is a t a ve ry e a rly sta g e o f th e in tro d u c tio n o f I E C 6 1 8 5 0 a n d re d e sig n e d th e e n g in e e rin g a n d te stin g to o l la n d sc a p e to se rve th e se p u rp o se s. A B B ’s com prehensive suite of softw are testing and com m issioning tools for substation autom ation system s A testing environm ent T he IEC 61850 standard is built m ainly on know n technologies such as extensible m arkup language (XM L), Ethernet, m anufacturing m essaging specification (M M S ) and transm ission control proto- col/Internet protocol (TC P /IP ), each of w hich have a num ber of w ell established softw are tools to handle them . W hy then w as it initially quite challenging to deal w ith IEC 61850-based system s? The crux of the m atter lies in the ap- proach taken. IEC 61850 seam lessly com bines the un- derlying technology com ponents and application aspects from an integral system point of view . Existing tools, how ever, w ere de- signed to focus on specialized single tasks, for exam ple c o m m u n ic a tio n analysis, and leave out any substation autom ation appli- cation aspects, and are therefore no lon- ger capable of addressing today’s chal- lenges. To overcom e this problem , it w as evident a new generation of softw are tools to efficiently m anage and support the IEC 61850 system integration pro- cess w as needed. A B B ’s approach, taken during the initial phase of the introduction of IEC 61850, w as to take the existing expert tools and identify clear functional gaps in them . This inform ation w as then used to de- velop (and afterw ards continuously im - prove) a com prehensive suite of softw are testing tools for com m unication, and protection and control application spe- cialists in the field of substation autom a- tion. W ith the benefit of active participation in the IEC 61850 standardization group on its side com bined w ith its in-depth know l- edge and experience in designing and building substation autom ation (S A ) sys- A B B developed the Integrated Testing Toolbox, a softw are tool suite used to m anage and support the IEC 61850 sys- tem integration process and w hich has proven invaluable in m any turnkey S A projects. 3 0 A B B review special report tem s, A B B developed the Integrated Testing Toolbox (ITT), a tool suite w hich has proven invaluable in over 900 turnkey S A projects delivered by the com pany. From the very beginning, A B B ’s approach w as to build a tool suite that w ould hide the com plexity of the technology com po- nents IEC 61850 is built on and focus on displaying application relevant data only. W hile having an in-depth know ledge of the technologies w as necessary to achieve this, the com plexity lay in creat- ing the interfaces that w ould enable the application and display layer of the test- ing tool to be tailored to project specific configuration data. S u b s ta ti o n c o n fi g u ra ti o n la n g u a g e ( S C L ) O ne of the greatest achievem ents of the IEC 61850 standard and one of the things that differentiates it from other com m unication standards w as the intro- duction of the substation configuration language (S C L). S C L m akes it possible to create files that are used for the ex- change of configuration data (eg, stan- dardized object m odels and data flow configurations of devices in a system ) betw een engineering tools. S everal file types have been defined in IEC 61850, and the content of each type depends on the role of a specific tool (e.g., system configuration tool or device configuration tool) that it is created for and the different evolution phases of the system integra- tion process. The system configuration description (S C D ) file is one such file type, and is de- fined as the m aster docum ent of a com - diagnosis and analysis of the running applications. C o n fo rm a n c e te s ti n g O ne very im portant aspect of IEC 61850 system integration is the selection of standard com plaint intelligent electronic devices (IED s). C om pliant in the sense that all selected IED s have been tested to ensure that they conform to the IEC 61850 standard and are officially certified by a test center w hich itself is accredited by the U C A international us- ers group. This certification covers the verification of the data m odel, the stan- dardized docum entation and a black-box test of all the com m unication services the IED supports. The conform ance test gives a m inim um guarantee that the se- lected IED s w ill interoperate w ith other certified devices if they are configured and loaded correctly w ithin the system . This prerequisite relieves the testing tools from research and developm ent related bits and bytes analysis even m ore. R e v e a li n g i n c o n s i s te n c i e s There are often situations, specifically during the testing and com m issioning phase of an IEC 61850 based system , w here tem porary inconsistencies due to stepw ise integration, the configuration of system s parts or sim ply hum an error re- sult in a situation w here distributed func- tions do not interoperate. D ebugging can be very tim e consum ing and often re- quires expert know -how , w hich is not al- w ays available. To handle such situations A B B has developed a tool called the ITT600 S A Explorer. It sim plifies the diag- nosis and troubleshooting of IEC 61850- based S A system s by com bining a set of plete S A system ➔ 1 . For creation and m aintenance, an IEC 61850 system con- figuration tool is required. From the system point of view , the inter- faces for each device (client or server) connected to the system are described in this file. This m akes the com plete S C D file the central part of the IEC 61850 sys- tem docum entation, w hich m akes it in- teresting to be used for all future activi- ties perform ed on the S A system , such as testing, m aintenance and extensions. The engineer no longer needs to w orry about error-prone m anual configuration of the testing and analysis tool environ- m ent; all he has to do is sim ply im port the project-specific S C D file into the test- ing tool. This in turn focuses the effort to w here it is m ost needed, on functional 1 Ty p i c a l c o n te n ts o f a s y s te m c o n fi g u ra ti o n d e s c ri p ti o n ( S C D ) fi le – D escription of com plete substation topology and prim ary equipm ent A ll protection and control devices (servers), and station level autom ation system (clients) including the standardized data m odels of their functionality A ll com m unication addresses C om plete horizontal and vertical data-flow w ithin the system R elationship betw een S A functionality and the prim ary equipm ent 2 A p p li c a ti o n a re a s fo r a n a ly ti c a l a n d d i a g n o s ti c to o ls 3 Ty p i c a l fe a tu re s o f a d i a g n o s i s a n d a n a ly s i s to o l – The use of project specific data (S C D file) for configuration Establishing an online com m unication connection to the IED s using either static or dynam ic configured data sets and control blocks for reports Visualizing the health of the running system C hecking data consistencies and configuration revisions against the S C D file A nalyzing and verifying running applications D ecoding Ethernet traffic to the substation autom ation (S A ) dom ain language based on the S C D file S how ing functional (system -oriented) or product-oriented addressing of logged data A B B ’S approach w as to build a tool suite that w ould hide the com plexity of the technology com ponents IEC 61850 is built on and focus on displaying applica- tion relevant data only. IEC 61850-8-1 IEC 61850-9-1 IE 3 1 A te s ti n g e n v i ro n m e n t To o ls s u p p o rt p ro c e s s e s To support the A B B project execution process the IEC 61850 sim ulation tool out of the ITT tool suite has proven to be very useful. S pecifically during engineer- ing phases or factory acceptance tests w hen not all system com ponents are physically available but nevertheless ap- plication tests m ust proceed, sim ulation of non-existing devices is essential for efficient w orkflow s. The IEC 61850 sim ulation tool can be connected either to the system bus or directly to an IED ➔ 7 . The S C D file that has been created and used during the engineering process of the specific S A system , and w hich is now part of the com m on system docum entation any en- gineer should have available w hen he goes on site, is then loaded into the tool. In both cases the tool could sim u- late one or m ore user selected clients/ servers based on the interface descrip- tion extracted from the S C D file. If the S C D file is m issing or incom plete, then the engineering and configuration w ork has to be com pleted first. B ased on this sim ulation, application tests on real sys- tem com ponents can be perform ed. If the process bus or additional injection hardw are is used, then closed loop test- ing of an IED is possible. Typical features of a sim ulation tool are sum m arized in ➔ 8 . Various substation autom ation projects have show n that the m ost obvious and com m on application for using G O O S E m essages is interlocking. The horizontal G O O S E service uses publisher-subscrib- er com m unication, w hich corresponds to pow erful online diagnostic tools w ith built-in intelligence to interpret IEC 61850 data. Typical application areas w ithin an S A system w here the ITT600 S A Explorer can be of great value is show n in ➔ 2 , w hile typical features of a diagnostic and analytical tool are listed in ➔ 3 . N arrow ing dow n a problem source basi- cally requires som e quick consistency checks ➔ 4 . O ne such check that can im - m ediately reveal inconsistencies involves com paring the correct offline configura- tion w ith the online com m unication –as it actually is –w orld. The com prehensive decoding by A B B ’s ITT600 S A Explorer of an IEC 61850 ge- neric object oriented substation event (G O O S E) m essage, w hich is used for horizontal real-tim e com m unication be- tw een m ultiple IED s, is illustrated in ➔ 5 . The on-screen display of clear text pro- tocol and application inform ation, w ith the m apping of it to the IEC 61850 S C D file in the background, gives an ex- cellent view of the corresponding online Ethernet traffic. A dditional checks on the IEC 61850 object m odel reveal potential sources of interoperability problem s. To o ls v i s u a li z e a p p li c a ti o n s A nother w ay of supporting the testing of distributed functions is show n in ➔ 6 . H ere the G O O S E m essages from m ulti- ple IED s can be displayed along a com - m on tim eline, m aking it easy to follow the interaction of various applications, such as interlocking or double com m and blocking. 4 C o n s i s te n c y c h e c k – c o m p a ri s o n o f a n S C D fi le w i th o n li n e d a ta u s i n g I T T 6 0 0 5 D e c o d i n g th e h o ri z o n ta l E th e rn e t tra ffi c w i th a n I E C 6 1 8 5 0 a n a ly z e r ( I T T 6 0 0 ) The ITT600 S A Explorer sim plifies the diagnosis and troubleshooting of IEC 61850-based S A system s by com bining a set of pow erful online diagnostic tools w ith built-in intelli- gence to interpret IEC 61850 data. 3 2 A B B review special report Te ts u ji M a e d a A B B S ubstation A utom ation S ystem s B aden, S w itzerland tetsuji.m aeda@ ch.abb.com neering and reloading of the configura- tion. A g ro w i n g tre n d The IEC 61850 standard is com plex and cannot be applied w ithout any signifi- cant softw are sup- port. The degrees of freedom and new possibilities that it offers, com - bined w ith varying levels of IEC 61850 integration, both in the configuration tools and IED s from different sup- pliers, em phasize the challenge even the m ore. Evidently, the strong trend tow ard the use of m ore m odern com m unication technology to distribute m ission critical data dem ands very advanced integration and verification processes. To m anage these challenges, engineering, testing and com m issioning tools have been de- veloped w hich incorporate all the possi- bilities offered by the IEC 61850 stan- dard. They have been proven to facilitate and ensure the high standards of A B B 's project execution. vertical server-client com m unication. In a situation w hen a specific IED “publishes” data for interlocking, eg, sw itch positions have failed (and therefore the IED m ust be taken out of service or disconnected from the com m unication bus), the sub- scribers of the now m issing data on the bus m ust be operated in an interlock- override m ode. This is because applica- tions running on the IED s usually refuse operations w ith obsolete data that have not been refreshed in tim e by the pub- lisher. M aintenance concepts for such situations m ust be considered in order to ensure that the rem aining healthy or un- affected parts of the system continue to w ork undisturbed. This type of situation can typically occur during the testing and com m issioning phase w here the sequen- tial adding of bays –including their con- trol and protection IED s –to an energized system should not lead to m ajor re-engi- 6 H o ri z o n ta l G O O S E c o m m u n i c a ti o n b e tw e e n m u lti p le I E D s w i th I T T 6 0 0 8 Ty p i c a l fe a tu re s o f a s i m u la ti o n to o l – U ses project specific data (S C D file) for configuration A n IED specific configuration can be extracted from the S C D file The consistent sim ulation of selected IED s R eal life sim ulation of com m unication services H orizontal com m unication –repeated sending of G O O S E m essages and cyclic sending of sam pled values Vertical com m unication –spontaneous sending of reports S etting any data configured in the IED s selected for sim ulation Tailored scripts for the sim ulation of sim ple applications, such as control applications double com m and blocking N ote: R eceiving IED s and clients cannot see any difference betw een sim ulated and real data on the bus 7 A p p li c a ti o n a re a s fo r s i m u la ti o n to o ls There is a strong trend tow ard the use of m ore m odern com - m unication technology to dis- tribute critical data and this dem ands m ore advanced integration and verification processes. IEC 61850-8-1 IEC 61850-8-1 IED sim ulation IEC 61850-9-2 M erging unit sim ulation IEC 61850-9-2 3 3 N e x t g e n e ra ti o n s u b s ta ti o n s H A N S -E R I K O L O VS S O N , T H O M A S WE R N E R , P E T E R R I E T M A N N – S u b sta tio n s a re a c ru c ia l e le m e n t fo r th e tra n sm issio n a n d d istrib u tio n o f e le c tric a l e n e rg y. T h e ir p rim a ry ro le is to tra n sfe r a n d tra n sfo rm e le c tric a l e n e rg y ( ste p p in g -u p o r d o wn th e vo lta g e ) . T h is is d o n e with h ig h vo lta g e switc h in g e q u ip m e n t a n d p o we r tra n sfo rm e rs. I n o rd e r to p ro te c t a n d c o n tro l, in stru m e n t tra n sfo rm e rs su p p ly th e sta tu s o f th e p rim a ry syste m to se c o n d a ry e q u ip m e n t. A B B h a s th e e x p e rtise , e x p e rie n c e a n d te c h n o lo g y to d e sig n a n d b u ild su b sta tio n s o f a n y size . Im pact of the process bus N ext generation substations 3 4 A B B review special report S ince the first substations w ere built m ore than 100 years ago, there has been trem en- dous developm ent of both the prim ary equipm ent (sw itchgear, pow er transform ers, etc.) and the secondary equipm ent (protection, control and m e- tering, etc). A B B has been engineering and con- structing substations from their very be- ginning and has delivered m ore substa- tions than any other supplier. The first substations deployed had air-insulated sw itchgear (A IS ). The developm ent focus for A IS w as on circuit breaker (C B ) tech- nology that w ould increase reliability and reduce m aintenance. In 1965 A B B deliv- ered the w orld’s first substation w ith gas- insulated sw itchgear (G IS ). W ith G IS the footprint of substations can be reduced by about 60 percent, by housing all pri- m ary conductors w ithin earthed S F 6 gas- insulated alum inum tubes. O ver the years new generations of G IS have been devel- oped, providing today’s G IS w ith, am ong other things, a considerably sm aller foot- print (for m ore detail see “C om pact and reliable”on pages 92-98 of ABB Review issue 1/2009). D ue to the reduced m aintenance of C B s, new substation design principles em erged for A IS in the late 1990s. The disconnecting function w as still required but m ore for m aintenance of overhead lines and pow er transform ers. This led to the developm ent of tw o types of solu- tions w ith disconnect sw itches (D S s) in- tegrated w ith the C B function. O ne w as a hybrid (PA S S TM ), w hich has a separate D S design in the sam e gas com partm ent as the C B . A nother one w as the discon- necting C B (D C B ), w hich uses the sam e contact for both breaking and discon- necting functions. D ue to the reduced m aintenance of C B s and the protection by S F 6 gas of the D S s’prim ary contacts from external pollution, the availability and reliability of A IS substations using hybrid or D C B has increased. Further- m ore the footprint of A IS substations us- ing this technique can now be reduced to about 50 percent. The latest step in substation develop- m ent com es w ith the introduction of the standard IEC 61850-9-2 for the process bus interface. For prim ary equipm ent, this m eans con- ventional instru- m ent transform ers (C IT) that use cop- per, iron and insu- lation m aterial pro- viding analogue values (1 A , 110 V) can be exchanged for fiber-optic sensors that send a pro- cess bus digital signal via fiber optic ca- bles to m etering, protection and control equipm ent. A s the use of sensors in- creases gradually over tim e the require- m ent for a secondary system to support both C IT and non-conventional instru- m ent transform ers (N C IT) during this transition period w ill becom e apparent. This requirem ent is obvious w hen ex- tending substations, since the new bays w ill contain N C ITs and existing bays w ill contain C ITs. The greatest physical im pact of process bus w ill be on A IS w ith live tank C B s or D C B s, w here the m easuring transform - ers can be integrated in the C B or D C B , allow ing the substation’s footprint to be reduced substantially. For hybrid and G IS solutions, the footprint reduction w ill be less significant as the insulation distance betw een prim ary and secondary equip- m ent is already reduced by the use of S F 6 gas. H ow ever, the process bus w ill enable the use of non conventional volt- age transform ers (VTs) m aking equip- m ent m uch lighter (a traditional VT is quite heavy). Further, the m anufacturing tim e can be reduced since all adapta- tions can be done w ith softw are and the hardw are can be standardized. B a y le v e l P ro c e s s le v e l S ta ti o n le v e l N e tw o rk c o n tro l S A w i th s ta ti o n b u s T ra d i ti o n a l M M I / c o n tro l b o a rd S A w i th s ta ti o n & p ro c e s s b u s 1 D e v e lo p m e n t o f s e c o n d a ry s y s te m s fo r s u b s ta ti o n s event recording protection S C A D A -distribution, m etering C opper cables C opper cables C opper cables S ensors & actuators B ay cubicle B ay cubicle B ay cubicle IED IED IED IED N C C S A S S A S N C C N C C R TU to other bays to other bays S tation bus S tation bus G atew ay/ protocol conv. G atew ay/ protocol conv. 1 9 7 5 1 9 9 5 2 0 1 0 Ye a r C opper cable 1 P rocess bus G IS G IS G IS The latest step in substation developm ent com es w ith the introduction of the standard IEC 61850-9-2 for the pro- cess bus interface. 3 5 N e x t g e n e ra ti o n s u b s ta ti o n s The introduction of the process bus w ill also m ean changes regarding interfaces for C B s and D S s. A ll signals, digital and analogue, to and from the control room can now be run via process bus in a few optical fibers instead of tons of copper cables. The C B s and D S s w ill include I/O electronics for signal transfer from opti- cal to electrical and vice versa. S e c o n d a ry s i d e d e v e lo p m e n ts The digital (r)evolution has provided tech- nical solutions for substations. D igital technology w as first im plem ented in sub- stations in the 1970s, providing com m u- nication channels from the substations to control centers ➔ 1 . D uring the early 1990s, w ith the in- creased capacity and speed of com put- ing and com m unications technology, digital protection and control devices, the so called IED s (intelligent electronic devices) w ere installed in substations. D igital com m unication betw een the IED s w as introduced using station bus w ith protocols that differed betw een m anu- facturers ➔ 1 . W ith the introduction of the IEC 61850 standard, substations are m oving into a new era regarding com m unications. A ll m anufacturers can adapt their products to the sam e com m unication m odel and protocol, m aking it possible for different m anufacturers IED s to “talk w ith each other”and thus interoperate on the sam e station bus, replacing all previous propri- etary protocols. ing can be m ade at the factory before delivery to site, leading to a secondary system of higher overall quality. A lso the architecture of the secondary system s w ill change com pared w ith today’s sub- stations. The bay house principle, in w hich the relay and control equipm ent are decentralized in the sw itchyard, w ill disappear since there w ill be no copper connections betw een the sw itchgear ap- paratus and m etering, protection and control devices, as the process devices can now be m ounted directly onto the prim ary apparatus. The central control room of the substation w ill becom e the natural location for relay and control equipm ent connected by fiber optics to m arshalling cubicles close to the prim ary equipm ent. Interface equipm ent, such as m erging units w ill be located in the m ar- shalling cubicle. P ro c e s s B u s – c o n n e c ti n g th e la s t m i le The w idely accepted standard IEC 61850 defines the com plete com m unications architecture for station and process bus to ensure a high level of device interoper- ability. The standard’s data m odels and com m unication services are the key to interoperability betw een m ulti-vendor substation protection, control devices (IED s), and station com puters (gatew ays) via Ethernet. A substation’s secondary system w ith station and bay level devices com m unicating over the so-called sta- tion bus has been w idely adopted by utilities and vendors ➔ 2 . The cyclic exchange of sam pled values, ie, betw een N C IT and IED devices for protection functions and other purposes is also defined in the standard (part 9-2). The interconnection betw een sensors, actuators, protection and control devic- es, is referred to as "process bus" (low er part➔ 3 ). This m eans that not only ana- log data, but also status inform ation from prim ary sw itchgear to IED s, as w ell as com m and signals from IED s to the pri- m ary sw itchgear can be exchanged. This interconnection betw een sensors, actua- tors, protection and control devices, is referred to as the “process bus”(low er part➔ 2 ). A vendor-agreed subset under the um brella of the utility com m unication architecture (U C A ) foundation has been in place since 2004. This subset speci- fies the exchange of sam pled values and is called IEC 61850-9-2LE (light edition). Today, pilot projects utilizing the process IEC 61850 also includes a new standard for the com m unication betw een the high- voltage apparatus and IED s, the so called process bus using the 9-2 profile and com m unications architecture. The pro- cess bus has high requirem ents on band- w idth since it w ill be used to transfer continuous sam pled values from the pri- m ary process. O n the secondary equipm ent side the m ost obvious physical change w ill be from copper cables to fiber optic cables. The m assive reduction of secondary ca- bling w ill m ean reduced cost for cables and associated equipm ent such as cable trenches and installation m aterial. M an hours for installation and testing on-site w ill be reduced and m ore thorough test- The w idely accept- ed IEC 61850 standard defines the com plete com - m unications archi- tecture for station and process bus to ensure a high level of device interoper- ability. 2 To p o lo g y o f s u b s ta ti o n s e c o n d a ry s y s te m s IEC 61850 process bus O perator w orkplace Engineering w orkplace C ontrol center G atew ay S w itch IEC 61850 station bus B ay controller B ay controller C onventional sw itchgear M odern sw itchgear M odern C T / VT’s M odern C T / VT’s IED A IED A IED B IED B 3 6 A B B review special report form ation and com m ands through the process bus. The location of the electronics depends on a num ber of criteria. P rim ary appara- tus w ith electronics integrated in the drive cubicles is one possibility. O n the other hand, it m ust be possible to handle cases w here the prim ary equipm ent does not yet contain com m unication interfaces. H ere, system integrators need to m ount the process electronics as near as pos- sible to the prim ary equipm ent, eg, to lo- cate them w ithin the m arshalling kiosks. I n te ro p e ra b i li ty a n d a rc h i te c tu re o n th e p ro c e s s b u s Field experience w ith sensors has been gathered for m ore than ten years now , m ostly in conjunction w ith protection and control equipm ent from the sam e vendor. For the process bus, utilities are execut- ing an increasing num ber of pilot installa- tions in order to gain experience. W ide- spread com m ercial adoption has not yet taken place. I n te ro p e ra b i li ty B oth the com m unication architectures (9-2, 9-2LE) and the steady-state behav- ior of sensors are defined (IEC 60044). The transient signal response of m erging units has not yet been standardized. The latter defines the extent (in term s of angle and am plitude) to w hich a m erging unit output signal is allow ed to differ from its corresponding input signal. This is es- sential since protection algorithm s and the corresponding data acquisition hard- w are and filtering has so far been “inter- connected”w ithin one device, the IED . N ow those parts are split up into differ- ent physical devices that can be supplied from different vendors, and therefore a transient signal response standard is es- sential for correct functioning. A new ly form ed w orking group w ith C igré (B 5.24) is addressing signal interoperability and results are expected during 2011. P ro c e s s b u s c o m m u n i c a ti o n a rc h i te c tu re s S everal different process bus architec- tures exist. In fact, depending on factors such as distance (location of M U s and IED s), com m unication capabilities (single port, m ultiple ports), available netw ork bandw idth, availability considerations or com m unication topologies, such as point-to-point, star or ring configurations the process bus architecture can vary considerably. B oth utilities and vendors bus for sam pled values are in operation already and the execution of the first com m ercial project for P ow erlink Q ueen- sland’s Loganlea 275 kV substation is w ell underw ay. M odern substations, both new installa- tions as w ell as the increasing num ber of secondary retrofit or extensions installa- tions w ill see both sensor and conven- tional instrum ent transform er technolo- gies side-by-side. The sam e applies for handling signaling com m ands and posi- tion indications to and from prim ary sw itchgear. R e a li z i n g th e p ro c e s s b u s W ith the process bus, new devices such as m erging units (M U ) for the optical sen- sors, as w ell interface units for conven- tional instrum ent transform ers, are need- ed. In addition sw itchgear controllers for circuit breakers and disconnectors (“B reaker IED s”) w ill be introduced. Those devices can be seen as conver- sion “endpoints”to and from the prim ary process to the secondary equipm ent. A m erging unit, as the nam e im plies, m erges various input signals into one digital output signal, eg, three phase sensors can have one com m on electron- ic unit, w hich transform the optical sig- nals from the sensors into digital sam pled values and m ake them available on the process bus. A sw itchgear controller contains elec- tronics for handling binary input and out- put signals (signal and pow er contacts). The device w ill com m unicate status in- 3 C o n tro l s y s te m a rc h i te c tu re a n d i ts li fe ti m e s B oth new installa- tions as w ell as the increasing num ber of secondary retro- fit or extension installations w ill see both sensor and conventional instrum ent trans- form er technolo- gies side-by-side. N e tw o rk c o n tro l c e n te r – O perator w orkplaces – S C A D A servers – Front-ends L i fe -c y c le 6 -1 0 y e a rs L i fe -c y c le 6 -2 0 y e a rs L i fe -c y c le 7 -1 0 y e a rs L i fe -c y c le 1 5 -2 5 y e a rs L i fe -c y c le 3 0 -4 0 y e a rs S u b s ta ti o n le v e l – S ubstation H S I – S ubstation gatew ay B a y le v e l – S econdary equipm ent – P & C IED s P ri m a ry e q u i p m e n t – S w itchgear – Transform ers R e m o te c o m m u n i c a ti o n – C om m unication equipm ent 3 7 N e x t g e n e ra ti o n s u b s ta ti o n s equipm ent such as cable trenches and installation m aterial. Testing at site w ill be very m uch reduced and m ore thorough testing can be m ade at the factory. This w ill lead to higher quality overall and a reduced tim e at site. C hanging to optical sensors (N C IT) w ill increase personnel safety since there w ill be no risk of injuries due to the inadver- tent opening of current transform er sec- ondary electrical circuits. For retrofit, the possibility of installing the new 9-2 process bus system in parallel w ith the existing system w ill allow the substation to rem ain in service during the m ain part of the w ork. This w ill be a big advantage, reducing outages to a m ini- m um , during the retrofit process. H a n s -E ri k O lo v s s o n A B B S ubstations Västerås, S w eden hans-erik.olovsson@ se.abb.com T h o m a s We rn e r P e te r R i e tm a n n A B B S ubstation A utom ation S ystem s B aden, S w itzerland thom as.w erner@ ch.abb.com peter.rietm ann@ ch.abb.com F o o tn o te 1 There are a num ber of solutions slightly different in architecture etc. that w ill be com pliant w ith IEC 61850. system or S C A D A , allow s continuous m onitoring of all connected secondary equipm ent. I n c re a s e d s y s te m a n d p e rs o n n e l s a fe ty R em ote control com bined w ith authority and rule-based access and rem ote test- ing, allow s increased system safety and security. P ersonnel safety is increased since m ore tests can be done w ithout putting the test personnel close to pri- m ary equipm ent or w ithout the risk of inadvertently opening current transform - er (C T) circuits. I n c re a s e d fu n c ti o n a li ty Fully distributed system architecture coupled w ith un-restricted com m unica- tion and process capability enables the system to add new functions easily w ith zero or m inim al outage tim e, giving the user additional benefit w ith respect to safe and secure system operation. I n te ro p e ra b i li ty B y deploying the IEC 61850 com pliant solution 1 , interoperability w ith regard to com m unications w ith other m anufactur- er’s equipm ent can be achieved. The benefit to custom ers is that IED s from different suppliers can be m ixed on the sam e bus w ithout concern for com m uni- cation incom patibilities. P ro s p e c ts The introduction of the IEC 61850-9-2 process bus standard in substations w ill give the follow ing m ain advantages: The footprint of prim ary sw itchgear can be reduced since fiber optic sensors (N C IT) can replace conventional m easur- ing transform ers. This w ill be m ost pro- nounced for air-insulated substations, especially w hen using live tank C B s. Traditional VTs are quite a heavy part of G IS and by using new sensor technology for voltage m easurem ent the equipm ent can be m ade m uch lighter. Further, the m anufacturing tim e can be reduced since all adaptations of N C IT can be done w ith softw are and their hardw are can be stan- dardized leading to an overall shorter de- livery tim e. O n the secondary side the m assive re- duction of secondary cabling by going from a lot of copper cables to a few fiber optic com m unication cables w ill m ean reduced costs for cables and associated are w orking on guidelines for reference topologies for such architectures. R e fu rb i s h m e n t a n d e x te n s i o n o f e x i s ti n g S A s y s te m s The typical life cycle of the prim ary and secondary equipm ent of a substation is illustrated in ➔ 3 . D uring the life tim e of the prim ary equipm ent the entire sec- ondary equipm ent or parts of the sec- ondary equipm ent are replaced betw een one to four tim es. The m ost interesting and future prrof m i- gration scenarios w ill be the ones in w hich IEC 61850-based equipm ent is in- troduced in steps to already installed system s. There are tw o m ain driving fac- tors for this: R etrofit and extension of substations or of system functionality. W ith the long life of prim ary equipm ent com pared to secondary equipm ent, there w ill be a continuous need for sec- ondary equipm ent replacem ent, w hile retaining the existing prim ary equip- m ent. B y introducing the process bus it w ill be possible to m ake a very efficient retrofit of protection and control system s w ith m inim um outage. W hile keeping the sub- station in service using the old equip- m ent, the new IEC 61850-9-2-based equipm ent can be installed and tested using new fiber optic cables laid in paral- lel to existing copper cables. A short out- age is necessary to connect the new protection and control equipm ent to the existing prim ary equipm ent. W hen the substation is taken into service again the old protection and control equipm ent to- gether w ith all copper cabling can be re- m oved or can rem ain. R e fu rb i s h m e n t d ri v e rs There are different reasons for refurbish- ing a substation or parts thereof. These can depend on the starting point (eg, w hether starting from a conventional re- m ote term inal unit, R TU , solution or from a proprietary num erical control system ). A ll of the below drivers m ay be applicable or only a selection of them . I n c re a s e s y s te m a v a i la b i li ty Exchanging of electrom echanical, static or old fashioned digital secondary equip- m ent w ith m odern num erical devices bundled to a real-tim e com m unication netw ork and connected to a higher level system such as a substation autom ation 3 8 A B B review special report C ase studies T h e g o a l o f I E C 6 1 8 5 0 is to fa c ilita te in te ro p e ra b ility o f su b sta tio n d e vic e s wh ile sim p lifyin g e n g in e e rin g a n d m a in te n a n c e . T h e e x a m p le s d e sc rib e d in th is se c tio n p re se n t so m e o f th e sta n d a rd ’ s su c c e sse s. R etrofitting for the future I t is in e vita b le th a t a s su b sta tio n s a g e , th e ir p a rts will n e e d to b e re p la c e d . T h e 3 8 0 /2 2 0 k V a ir-in su la te d su b sta tio n ( A I S ) lo c a te d in th e A lp s in S ils, S witze rla n d wa s o n e su c h c a se . I ts se c o n d a ry in fra stru c tu re – ie , p ro te c tio n , c o n tro l a n d m e te rin g – a n d p a rts o f its p rim a ry e q u ip m e n t a t th e 3 8 0 k V le ve l – ie , switc h g e a r, p o we r tra n sfo rm e rs a n d c irc u it b re a k e rs – h a d re a c h e d th e e n d o f th e ir life c yc le s. T h e o p e ra to r K H R ( K ra ftwe rk e H in te rrh e in ) th u s tu rn e d to A B B fo r a n e c o n o m ic a lly fe a sib le , sta n d a rd ize d a n d fo rwa rd -lo o k in g so lu tio n fo r o n e o f th e m o st im p o rta n t n o d e s o f th e S wiss tra n sm issio n n e two rk . T h e a n swe r: a su b sta tio n a u to m a tio n re tro t u sin g I E C 6 1 8 5 0 te c h n o lo g y. Im plem enting the IEC 61850 standard enables availability of all necessary inform ation –w hich supports exten- sions, replacem ents or upgrades of all or part of the substation autom ation system –and enables integration of products from different suppliers. It also ensures data consistency w ithin the com plete system and defines the engineering processes, helping to keep data and data flow consistent for the w hole substation. In this project, the horizontal bay-to-bay com m unica- tion m odel G O O S E w as used to considerably reduce the copper w iring betw een the bays. A ll inform ation for interlocking betw een bays is now exchanged betw een the A B B R elion ® 670 series IED s on the IEC 61850 bus via G O O S E m essages. Although testing w as a m ajor part of the retrofi t, the greater challenge w as to avoid a shutdow n during com m is- sioning. O utage tim e of individual feeders had to be m inim ized and coordinated w ith the grid operator m onths in advance. The com plete system w as m anufactured and delivered to the site w here, except for the connection to the A IS interfaces, it w as installed. O nce the dedicated bay w as com m issioned, the new IED s w ere connected to the prim ary equipm ent. The substation w as confi gured to enable concurrent operation of the existing and new equipm ent during this transition phase. A fter successfully retrofitting the 380 kV substation, the 220 kV part w as integrated into the new control system . The existing IED s w ere equipped w ith a new IEC 61850 com m unication interface, allow ing com m unication w ith the new M i- croS C A D A control system and ensuring that both the 380 kV and 220 kV sw itchyards could be operated and m onitored from the central control system . A hot standby system w as put in place to provide backup should a failure occur. M a rc e l L e n z i n A B B S ubstation A utom ation S ystem s B aden, S w itzerland m arcel.lenzin@ ch.abb.com IEC 61850 at w ork 3 9 C a s e s tu d i e s C hallenges build partnerships I n 2 0 0 6 , A B B su p p lie d a p io n e e rin g su b sta tio n -a u to m a tio n p ro je c t to th e B ra zilia n g o ve rn m e n t p o we r tra n s- m issio n u tility, E le tro su l. T h is u tility is re sp o n sib le fo r e le c tric a l tra n sm is- sio n in th e so u th o f B ra zil. T h e p ro - je c ts d e live re d we re b a se d o n th e I E C 6 1 8 5 0 sta n d a rd , with a p p lic a tio n s u sin g m e ssa g e s b e twe e n I E D s, G O O S E 1 , re d u n d a n t c o n tro l u n its a n d fe a tu rin g in te ro p e ra b ility b e twe e n syste m s fro m d iffe re n t ve n d o rs. The first project consisted of three substations, “A tlântida 2”, “G ravataí 3”and “O sório 2”. These are 230 kV and 138 kV transm ission substations. “A tlântida 2”uses 60 IED s (14 w ith redundancy and 32 w ithout) for protection, acquisition and control. These are m apped to 13,683 dynam ic objects from a total of 28,786 objects available in the IED . A bout 3,300 of these w ere distributed to centers of higher hierarchy. R e d u n d a n t c o n tro l R edundant control w as one of the special challenges of this project. This philosophy, used by Eletrosul for m any years, uses tw o control term inals (for A B B ’s projects this m eant tw o R EC 670s). These have exactly the sam e functionality in term s of control logic, interlocking and autom atism s for controlling a certain num ber of bays. B oth units are active, but just one is m onitored by the supervisory system . In case of unavailability of a term inal, the S C A D A system sw itches to the other IED . B ased on this philosophy, Eletrosul clearly defines how a system should react, for exam ple, in contingency situations. B riefly, the term inal m anaged by the supervisory system is m onitored and executes rem ote com m ands. In case of interlocks, the tw o redundant term inals send signals to external bays. This affects the philosophy of treatm ent of these redundant signals by the receiving logic. In this project, G O O S E w as w idely used both for m onitoring the active term inal and for interlocks and autom atic logics. This perm itted a considerable saving of cables, as tw ice as m any signals are generated and received in this philosophy versus a philosophy of sim ple control. I n te ro p e ra b i li ty Eletrosul uses S A G E (an open-source energy-m anagem ent system ) as S C A D A softw are. S A G E w as devel- oped by C EP EL, a B razilian govern- m ent research center. The M M S protocol defined in IEC 61850 w as im plem ented in S A G E in 2006. The A B B project w as thus a test of the standard’s interoperability. This test w as passed successfully. R e s u lts A nother request from Eletrosul w as to m inim ize the num ber of hours required for the preparation of texts in the system database. For this, it encour- aged the use of generic signs (G G IO s) to be m inim ized. Even so, in the control term inals that use m any m onitoring aspects not defined in the standard (m ostly com plex interlocks and autom atic logic) the use of G G IO s is still very high. It is hoped that as the IEC 61850 standard evolves, m ore standard signs w ill be provided. In IED protection, it w as found that the use of G G IO s w as reduced because of the standard, and because A B B IED s use standards for all protection functions. The three substation projects fostered a spirit of partnership betw een Eletrosul and A B B , resulting in new projects being carried out together delivering the benefits of IEC 61850. M a u rí c i o P e re i ra A B B P ow er S ystem s G uarulhos, S ão P aulo, B razil m auricio.pereira@ br.abb.com G o n z a lo H u m e re s F lo re s Eletrosul F o o tn o te 1 G O O S E: G eneric O bject O riented S ubstation Event 4 0 A B B review special report P ortuguese transm ission substations R E N is th e m a in P o rtu g u e se u tility fo r e le c tric a l e n e rg y tra n sm issio n . A B B su p p lie d th e u tility’ s rst I E C 6 1 8 5 0 syste m , in sta llin g it a t th e 4 0 0 /2 2 0 k V L a g o a ç a su b sta tio n . T h e in sta lla tio n is re sp o n sib le fo r so m e o f th e m o st im p o rta n t in te rc o n n e c tio n p o in ts with th e S p a n ish g rid o n th e 4 0 0 k V vo lta g e le ve l. O f all the benefits of m igrating substation autom ation system s to the new standard, the custom er w as especially focused on one in particu- lar: standardizing the system architec- ture, ie, using the sam e netw ork topology and overall arrangem ent independently of the supplier. A B B brought m uch experience into this project that it had built up in previous deliveries to the custom er. The previous platform m ay have been different, but m arked an excellent starting point and perm itted A B B to quickly identify the required solution. The Lagoaça substation uses a system based on a decentralized Ethernet ring. The m ain products from A B B are: –M icroS C A D A P ro for local H M I, and autom ated sequences –C O M 500i as G atew ay, for com m u- nication w ith netw ork control center –IED 's 670 for control and protection units –R EB 500 S ystem s for busbar protection Third party products used w ere: –S w itches and routers from R U G G ED C O M –M einberg G P S servers for S N TP tim e synchronization –C om puters w ith no-m oving parts running W indow s XP Em bedded platform –K VM sw itches and fallback sw itches from B lack-B ox –Industrial com puters from A dvan- tech, for rem ote access and engineering stations. –R TU servers and local-event printing system from S YC O M P G erm any (R EN m andatory). –R em ote access via R X1000 routers from R U G G ED C O M The adoption of IEC 61850 w as clearly beneficial. It allow s both custom ers and vendors to retain extensive functional freedom in their definitions and philosophies. It also assures independence from single suppliers as w ell as cost savings in both engineering and m aintenance. C a rlo s C a e ta n o A B B S ubstation A utom ation S ystem s P aço de A rcos, P ortugal carlos.caetano@ pt.abb.com W uskw atim transm ission system I n o rd e r to stre n g th e n th e e x istin g 2 3 0 k V n e two rk , M a n ito b a H yd ro m a in u tility in M a n ito b a c o n tra c te d with A B B fo r th e d e sig n , e n g in e e rin g , su p p ly a n d c o m m issio n in g o f Wu sk - wa tim Tra n sm issio n S yste m C o m p le x , c o m p risin g th re e n e w sta tio n s a n d e x p a n sio n o f fo u r e x istin g o n e s. T h e n e w sta tio n s fe a tu re d d istrib u te d c o n tro l, b a y p ro te c tio n a n d a b a y c o n tro lle r c o n c e p t. T h e e n tire c o n tro l a n d c o m m u n ic a tio n p ro c e ss u se d th e I E C 6 1 8 5 0 sta n d a rd . P rotection devices w ere sourced from three different m anufacturers. In fact the use of different suppliers w as a requirem ent of the protection redun- dancy concept. P rior to IEC 61850 such integration w ould have been challenging if not im possible, espe- cially for large system s due to incon- sistency of data and engineering. The IEC 61850 engineering approach and data structure using S C L language signi cantly facilitated the engineering of interfaces betw een different units. The descriptive pow er of the SC L language enabled part of the integra- tion to occur w ithout having access to all devices or bay level inform ation. B ecause design, m anufacturing and testing of the tw o SA system s w as com pleted in close colaboration betw een AB B and M anitoba H ydro, an attuned and future-proof system w as delivered. The IEC 61850 standard m ade it possible to com bine and inte - grate AB B , Siem ens and Areva Protec- tion IED s w ithin the SA and thus to ful ll safety requirem ents. The use of G O O SE m essages for bay-to-bay interlocking and intertrip reduced the am ount of copper w iring required. The com plete com m unication of the substations are now described and docum ented in SC D - les, w hich is of advantage for the future m aintenance and extension of the stations that are now in service. M a n s o u r J a la li A B B S ubstation A utom ation S ystem s B urlington, C anada m ansour.j.jalali@ ca.abb.com 4 1 C a s e s tu d i e s The S tar of Laufenburg shines T h e 3 8 0 k V L a u fe n b u rg su b sta tio n – o n e o f th e la rg e st a n d m o st im p o rta n t in E u ro p e – b o o sts se ve ra l wo rld p re m ie re s. S ta yin g a b re a st o f th e d e ve lo p m e n t a n d e x te n sio n o f I E C 6 1 8 5 0 , its o wn e rs, th e S wiss u tility E G L A G , we re th e rst to e q u ip a h ig h -vo lta g e su b sta tio n with a n I E C 6 1 8 5 0 a u to m a tio n syste m , d o in g so sh o rtly a fte r th e re le a se o f th e sta n d a rd in 2 0 0 4 , a n d e ve n o p tin g fo r a m u lti-ve n d o r so lu tio n . Two ye a rs o n , th e u tility issu e d th e ve ry rst o p e n te n d e r b a se d o n a S C D ( su b sta tio n c o n g u ra tio n d e sc rip tio n ) le , a n d m o st re c e n tly im p le m e n te d th e 9 -2 p ro c e ss b u s. W hen built in 1967 at the inception of the European grid, the Laufenburg substation, w ith its key position in term s of interconnection and m eter- ing, w as dubbed the “S tar of Laufen- burg”. It w as extended and upgraded from 1979 to 1981. From 2004 to 2009, EG L undertook the follow ing refurbishm ent w ork: –S tep 1: retrofit of prim ary and secondary equipm ent –S tep 2: replacem ent of old station H M I –S tep 3: pilot project for IEC 61850-9-2 S te p 1 : B a y re tro fi t B oth prim ary and secondary equip- m ent of the 17 feeders w as replaced in a bay-by-bay m anner, w arranting an alm ost interruption-free retrofit. The m igration w as supported by a com - pact hybrid solution that connects the new gas-insulated sw itchgear (G IS ) m odules to the existing air-insulated sw itchgear (A IS ) busbar using silicon bushings. The G IS m odules com pris- ing circuit breaker, disconnector, earthing sw itch and instrum ent transform ers w ere pre-tested to enable short installation tim es. They offer m axim um operational safety and high im m unity to environm ental conditions. They also require less space and sim plify m aintenance as replacem ent of a com plete pole can be perform ed in less than 24 hours. The future-proof secondary retrofit concept addressed the varying lifecycles of bay and station-level equipm ent. W ith the latter equipm ent being retained, A B B integrated its new IEC 61850 com pliant bay control and protection IED s (Intelligent Electronic D evices) to the third-party control system using a gatew ay converting IEC 61850 to IEC 60870-5-101. A B B also successfully integrated a third- party m ain protection device w ith an IEC 61850 interface. C onsistency of bay data during the stepw ise upgrade w as supported by pre-configuring and pre-testing using an S C L-based tool. S te p 2 : S ta ti o n -le v e l re p la c e m e n t In 2007, A B B w on an open tender for the replacem ent of the old station H M I (hum an-m achine-interface). A B B installed a new IEC 61850 H M I fully re-using the engineering data from the S C D file generated for the bay retrofit. S te p 3 : I n tro d u c ti o n o f p ro c e s s b u s The pilot installation contains a selection of products and system s ready for the IEC 61850 process bus. O n the prim ary side, there is a com bined and fully redundant C P -3 current and voltage sensor w ith m erging units for protection and m etering. O n the secondary side, a R EL670 line distance protection IED and a R EB 500 busbar protection system w ith three bay units are in operation. M etering is perform ed by an L+G energy m eter. For supervision and easy access, a S A S using IEC 61850 station bus com pletes the pilot installation. The pilot is running in parallel to the conventional control and protection system and enables collection of long- term real-life experience as w ell as com parison of behavior. S ince its com m issioning in 2009, the system has been in continuous operation. P e tra R e i n h a rd t A B B S ubstations B aden, S w itzerland petra.reinhardt@ ch.abb.com S te fa n M e i e r A B B S ubstation A utom ation S ystem s B aden, S w itzerland stefan.m eier@ ch.abb.com 4 2 A B B review special report W hen tw o becom e one J O H A N H A N S S O N , S T E F A N B O L L M E YE R – T h e su c c e ssfu l in tro d u c tio n o f th e I E C 6 1 8 5 0 sta n d a rd so m e six ye a rs a g o h a s a lre a d y b ro u g h t h u g e b e n e ts to p o we r d istrib u tio n a n d su b sta tio n a u to m a tio n in te rm s o f sc a la b ility, in te ro p e ra b ility, sa fe ty a n d d a ta m a n a g e m e n t. E ve n th o u g h it wa s d ra fte d b y su b sta tio n a u to m a tio n d o m a in e x p e rts, it is b y n o m e a n s e x c lu sive ly re se rve d fo r th a t d o m a in a lo n e . I n fa c t, I E C 6 1 8 5 0 is m o re th a n c a p a b le o f o p e ra tin g in o th e r a re a s, su c h a s in p ro c e ss a n d p o we r g e n e ra tio n p la n t a u to m a tio n . T h e se p la n ts a re c o n tro lle d a n d m o n ito re d fro m a c e n tra l c o n tro l ro o m in wh ic h th e re a re typ ic a lly two d iffe re n t syste m s d e p lo ye d ; o n e fo r p ro c e ss c o n tro l a n d th e o th e r fo r m o n ito r- in g a n d c o n tro llin g th e e le c tric a l syste m . P la n t o p e ra to rs, in th e ir q u e st to re d u c e c o m p le x ity a n d o p tim ize e f c ie n c y h a ve b e e n a c tive ly se e k in g so lu tio n s th a t o ve rc o m e th e se p a ra tio n o f th e syste m s a n d th e e x tra c o sts a sso c ia te d with it. IEC 61850 in com bination w ith A B B ’s aw ard-w inning Extended A utom ation S ystem 800xA is opening doors to new and cost-effective solutions. 4 3 Wh e n tw o b e c o m e o n e Even though it w as drafted by substa- tion autom ation dom ain experts, the IEC 61850 standard is capa- ble of operating in process and pow er generation plant autom ation. trol system , IED m onitoring and control is usually im plem ented by a separate sub- station autom ation (S A ) system w hile connectivity betw een the electrical sys- tem and process control is lim ited to the m ost essential data, eg, for interlocking purposes. A lthough only a lim ited set of signals is selected for data exchange, to- day’s practice for this type of electrical and control system interfacing, such as hardw iring or M odbus connectivity, still requires significant hardw are and engi- neering efforts. The presence of tw o dif- ferent system s also increases costs be- cause, for exam ple, different spare parts and a duplicated effort to ensure integra- tion w ith enterprise level system s are re- quired ➔ 1 . To help plant operators overcom e these expensive com plexities, IEC 61850, w ith its standardized com m unication proto- cols and data m odel, in com bination w ith A B B ’s aw ard-w inning Extended A utom a- tion S ystem 800xA is opening doors to new and cost-effective solutions. T he integration of field instru- m ents into process control ap- plications is based on a lim ited set of industry standards that provide harm onized access to process data and diagnostics. For electrical equipm ent, how ever, a m ultitude of dif- ferent, often proprietary com m unication protocols is deployed. Therefore electri- cal system s, especially those com posed of equipm ent from different vendors, are often characterized by m ultiple different interfaces, a broad variety of engineering tools, protocol converters and gate- w ays. P rocess control system s typically do not offer built-in support for those com m uni- cation protocols and data m odels. A nd because of this significant engineering and adaptation efforts need to be m ade on a project-by-project basis to m ake the increasing am ount of inform ation, w hich m odern intelligent electronic de- vices (IED s) provide, available to a m oni- toring and control system . N ow adays to m itigate the im pact on the process con- I E C 6 1 8 5 0 i n te g ra ti o n i n S y s te m 8 0 0 x A The com bination of A B B ’s Extend- ed A uto m ation S ystem 800xA w ith IEC 61850 not only addresses the above- m entioned end-user dem ands, but it also gives greater synergy and flexibility to fully integrated plant operations. Introduced in D ecem ber 2003, S ystem 800xA provides a scalable solution that extends traditional process control by in- corporating: safety; discrete logic and sequence control; production m anage- m ent; inform ation m anagem ent; sm art instrum entation; asset m anagem ent; and docum ent m anagem ent. B ased on A s- pect O bject technology, S ystem 800xA is capable of adopting data m odels from different disciplines and m aking them available in a harm onized w ay through a singular virtual database environm ent. The integration of IEC 61850 into S ystem 800xA supports both generic object ori- ented substation events (G O O S E) and m anufacturing m essage specification (M M S ) protocol options described in the 4 4 A B B review special report zation w orkflow s can be harm onized once IED data is available in S ystem 800xA , allow ing instrum ent m aintenance engineers and those servicing electrical devices to w ork from the system ’s com - m on m aintenance w orkplace. S ystem 800xA’s m aintenance structure gives an overview of all plant assets in a single dis- play. C onditions can be m onitored, and diagnostics and m aintenance related alarm s for electrical devices and process instrum ents are presented in practically the sam e fashion. For further in-depth analysis, additional IED data points can be subscribed to or disturbance records can be uploaded. A ccess-right settings ensure that only authorized people are al- low ed to perform such detailed analysis. A s the ultim ate step, S ystem 800xA’s A s- set O ptim ization functionality can be in- tegrated w ith a com puterized m ainte- nance m anagem ent system (C M M S ) so that w ork order handling is autom atically treated the sam e for both electrical and process equipm ent. This elim inates the need for separate w orking procedures or the adaption of different system s to the C M M S . The possibility of electrical integration presented by A B B ’s S ystem 800xA in com bination w ith IEC 61850 has been keenly observed by industries other than pow er distribution. The O il & G as and P ow er G eneration industries in particular have been evaluating these new oppor- tunities and som e have even taken the first steps tow ard the im plem entation of such a system . tion configuration file to create all data item s for vertical integration as w ell as the connections for horizontal com m uni- cation. S eparate gatew ay configuration or additional project-specific softw are in- terfaces becom e obsolete. To be m ore specific, S ystem 800xA seam lessly integrates IEC 61850, deliv- ering the features and benefits requested by end users, such as: –R educed cost of ow nership through few er com ponents and spare parts, and less system adm inistration. –G reater flexibility as integration is m uch less com plicated than before and the interfaces adapt easier to changes. –C entralized data recording, including the plant-w ide sequence of events and a harm onized interface to enterprise level system s. –A com plete view of electrical system data, especially to process operators so they can m ake educated decisions. –Im proved operator effectiveness w ith one user interface that can consis- tently present plant-w ide data, enable data access and display operating procedures. B ecause of its flexibility, S ystem 800xA allow s the configuration of individual w orkplaces for both electrical and pro- cess operators so that they can retain the graphical displays and w orkflow s fam iliar to them w hile operating in a single envi- ronm ent. M aintenance and asset optim i- standard. G O O S E com m unication is di- rectly connected to the A C 800M con- troller (one of m any from the S ystem 800xA fam ily of controllers) via a com - m unication interface so that the data be- com es available in the controller applica- tion. This so-called horizontal integration 1 enables the A C 800M controller to com - m unicate w ith all other IED s on the sam e IEC 61850 netw ork in real tim e ➔ 2 . M oreover, the A C 800M controller acts like an IED on the IEC 61850 netw ork, and can therefore be involved in load shedding or other pow er m anagem ent applications. M M S com m unication is used for the ver- tical integration of IEC 61850. Via an O P C 2 interface, S ystem 800xA has di- rect access to all IED data such as cur- rent and voltage m easurem ents, status, interlocking, tim e-stam ped alarm s and events. The system can also send open and close com m ands to IED s. Logical nodes (LN s) of IED s are m odeled as A s- pect O bjects in S ystem 800xA and there- fore all system features, such as freely configurable graphics, faceplates, alarm s and event lists, and historian capabilities are available for IED data. To engineer IEC 61850 integration, S ys- tem 800xA uses the inform ation con- tained in the substation configuration description (S C D ) file, w hich describes the com plete substation configuration. S ystem 800xA processes the extensible m arkup language (XM L) based substa- The Flåsjö facility is one of the rst hydro pow er plants to utilize a com bi- nation of IEC 61850 and System 800xA for process and substation auto- m ation. P ro c e s s i n s tru m e n ta ti o n P ro c e s s e le c tri fi c a ti o n S u b s ta ti o n a u to m a ti o n P o w e r m a n a g e m e n t P ro c e s s a u to m a ti o n P o w e r a u to m a ti o n 1 T ra d i ti o n a l p ro c e s s c o n tro l s y s te m s d o n o t o ffe r b u i lt-i n s u p p o rt fo r p ro p ri e ta ry c o m m u n i c a ti o n p ro to c o ls a n d d a ta m o d e ls S ystem servers O perator w orkplace for process autom ation O perator w orkplace for pow er autom ation S ystem netw orks C ontrollers Instrum ents Fieldbuses LV S w itchgear D rives M otor controllers S C A D A S erver S ystem netw orks G atew ay/ P rotocol converter P rotection & C ontrol IED s H ardw ired S erial buses P rotocol 1 P rotocol 3 P rotocol 2 4 5 Wh e n tw o b e c o m e o n e For substation autom ation, the IED s are the m ost critical devices in the plant in that they provide protection, control and m onitoring of generators and lines from the outgoing high-voltage substation. Three native IEC 61850 com pliant A B B R elion ® IED s are integrated w ith S ystem 800xA, tw o redundant R EG 670 IED s are used for generator protection and one R EL670 for protection of the outgoing 130 kV line. A ll the IED s are integrated w ith the A C 800M controller using IEC 61850-defi ned G O O S E. This enables the AC 800M controllerto function not only as the process controller, but also to act as an IED on the IEC 61850 netw ork, com m unicating horizontally w ith all other IED s as w ell as w ith the control center via satellite com m unication. Im portant data from the IED s include m easurem ents such as pow er, reactive pow er, voltages and currents, together w ith breaker and dis- connector statuses ➔ 4 . This data is dis- played at the local S ystem 800xA opera- tor w orkplace and the control center in Sundsvall som e 260 km aw ay from w here the system is usually m onitored and con- trolled ➔ 5 . In addition, alarm s and events from the com bined process and substa- tion autom ation system are also transm it- ted to S undsvall, providing operators w ith valuable inform ation about the plant. A t the control center, the operators m onitor and control the plant using an A B B N et- w ork M anagem ent System . They also have rem ote access to the S ystem 800xA operator w orkplace, providing a redun- dant connection to the control system . E . O N i n te g ra te s s u b s ta ti o n a n d p ro c e s s a u to m a ti o n E.O N Vattenkraft, a subsidiary of E.O N S verige, is the third largest hydroelectric pow er producer in S w eden. In a typical year it produces about 8 TW h from 77 hydro pow er plants, from K ristianstad in the south to Lycksele in the north. M ost of these plants w ere built betw een the 1950s and 1970s using w hat is now con- sidered legacy technology. U p to 2015, E.O N plans to invest S EK 6 billion ($763 m illion) in safety, renew al and productivity im provem ents in installed pow er plants. A ll of E.O N 's hydro pow er plants are usu- ally operated rem otely from the central control center in S undsvall, and are visit- ed only for m aintenance reasons. O ne of these, the Flåsjö hydro pow er plant, w as the rst upstream plant installed on the river Ljungan in northern Sw e- den ➔ 3 . Since 2009, it holds the distinc- tion of being one of the rst hydro pow er plants in the w orld to utilize a com bination of IEC 61850 and System 800xA for both process and substation autom ation. In the installation at Flåsjö, the original relay-based system w as replaced by one S ystem 800xA together w ith an A C 800M controller. P rocess control handles appli- cations such as turbine control, vibration protection and synchronization. P rocess electrification and control of auxiliaries and pum ps are done using P rofibus com m unication w ith A B B ’s m odular low - voltage sw itchgear M N S . 3 T h e F lå s jö h y d ro p o w e r p la n t U pstream , Flåsjö is the first of E.O N ’s hydropow er plants on the 350-kilom eter long river Ljungan. The Ljungan runs to the northeast of H elagsfjället and flow s into the G ulf of B othnia just south of S undsvall. The pow er plant w as built in 1975 and has a m axim um w aterfall of 46 m eters and a flow through the turbine of 60 m 3 per second. The Flåsjö plant produces about 73 G W h w ith an installed capacity of 24 M W . The plant is unm anned, and controlled and m onitored from E.O N Vattenkraft’s control center in S undsvall. C om m unications betw een the pow er plant in Flåsjö and the control center in S undsvall is via satellite transm ission. The use of IEC 61850 w ith a single control system provided E.O N w ith the m eans to investi- gate the benefits of using the stan- dard for standard- ized system inte- gration, application building, installa- tion and testing. 2 C o m m u n i c a ti o n w i th a ll o th e r I E D s o n th e s a m e I E C 6 1 8 5 0 n e tw o rk i s p o s s i b le i n re a l ti m e LV S w itchgear D rives M otor controllers Fieldbuses H orizontal integration S ystem netw orks A C 800M controller Vertical integration IEC 61850 P rotection & C ontrol IED s S ystem servers Instrum ents P ro c e s s i n s tru m e n ta ti o n P ro c e s s e le c tri fi c a ti o n S u b s ta ti o n a u to m a ti o n P o w e r m a n a g e m e n t I n te g ra te d p ro c e s s a n d p o w e r a u to m a ti o n C om m on operator w orkplace for process and pow er autom ation 4 6 A B B review special report w hen so m any pow er plants are con- trolled from one location, it’s very im por- tant that there is a standard on w hich everything is based. From an E.O N point of view , there are m any benefits of using IEC 61850 and S ystem 800xA : –C om plete system configuration is m ore efficient and safer because standardized solutions for IED configuration, substation autom aton design and control system program - m ing are used. –The testing of protection, control and m onitoring functions can be carried out before installation begins, and this helps to m inim ize the dow ntim e needed for installation and com m is- sioning. –IEC 61850 is standard for Ethernet- based com m unication solutions and that m eans reduced w iring, w hich in turn leads to shorter installation tim e and reduced sources of errors during operations. –W ith im proved access to electrical and process data from the entire plant, the focus is shifted from troubleshooting to m ore preventive m aintenance. The system itself can indicate w hen a com ponent needs servicing or replacing. –A com m on event list for both the process and electrical m onitoring m akes it easier to m onitor errors and draft m aintenance plans. These benefits are such that according to A ssar S vensson, E.O N w ill continue to ask for IEC 61850 in its specifications: M a i n b e n e fi ts The use of IEC 61850 w ith a single con- trol system in the Flåsjö hydro pow er plant w as a pilot installation for E.O N . It provided the m eans from w hich the com - pany could investigate the benefits of us- ing the renow ned global standard for substation autom ation not only as a com m unication protocol for devices, but also for standardized system integration, application building, installation and test- ing. The success of this pilot project is very im portant to E.O N because it w ill in- fluence the upgrade of the substation and process control system s in other hydro pow er plants. A ssar S vensson w orked on technology assessm ent and plant design for the pow er plant in Flåsjö and is now involved in the m ajority of E.O N Vattenkraft’s up- grades and m odernizations ➔ 6 . O f the renew al plans for the hydropow er plants, he says, “this is an extensive conversion job w e have ahead of us. W e’re therefore looking for standardized solutions in ac- cordance w ith IEC 61850. Thus far, it only concerns relay protection.”For E.O N , IEC 61850 w ill provide new op- portunities to increase availability and sim plify engineering. S everal standard- ized com ponents provide the capability to build plants in a m ore structured m an- ner. “W e w ant to be able to receive deliv- eries in w hich all com ponents can be tested together prior to initiating opera- tions.”A nother im portant reason for a m ore standardized structure for the con- trol system s is that all E.O N Vattenkraft facilities in S w eden are controlled from a single control center. S vensson says that 6 A s s a r S v e n s s o n is in v o lv e d in m a n y o f E . O N Va tte n k ra ft’ s u p g ra d e s a n d m o d e rn i z a ti o n s 4 I E D d a ta i n c lu d e p o w e r, re a c ti v e p o w e r, v o lta g e a n d c u rre n t m e a s u re m e n ts 5 T h e c o n tro l c e n te r i n S u n d s v a ll fro m w h i c h a ll o f E . O N ’ s h y d ro p o w e r p la n ts i n S w e d e n a re c o n tro lle d a n d m o n i to re d “I now have m ajor expectations regarding our supplier’s ability to give us additional capabilities to standardize and sim plify construction of electrical and control system s for hydropow er plants. W ith the installation in Flåsjö, w e have hopefully just opened the door to the future.” J o h a n H a n s s o n A B B A B Västerås, S w eden johan.hansson@ se.abb.com S te fa n B o llm e y e r A B B A utom ation G m bH M inden, G erm any stefan.bollm eyer@ de.abb.com F o o tn o te s 1 H orizontal integration can also replace the hardw iring traditionally used for interlocking signals. 2 O bject linking and em bedding (O LE) for process control 4 7 I E C 6 1 8 5 0 E d i ti o n 2 K L A U S -P E T E R B R A N D , WO L F G A N G WI M M E R – T h e n a l p a rt o f I E C 6 1 8 5 0 E d itio n 1 “ C o m m u n ic a - tio n N e two rk s a n d S yste m s in S u b sta tio n A u to m a tio n ” [1 ] wa s p u b lish e d in J u n e 2 0 0 5 . A m o n g th e sta n d a rd ’ s g re a te st a c h ie ve m e n ts a n d b e n e ts a re th e u se o f sta n d a rd ize d se m a n tic s a n d a fo rm a l syste m d e sc rip tio n ( th e la tte r b e in g th e k e y to e f c ie n t e n g in e e rin g o f su b sta tio n a u to m a tio n syste m s) a s we ll a s it b e in g e m b e d d e d in to th e b ro a d e r sc o p e o f p o we r-syste m m a n a g e m e n t. S in c e its in tro d u c tio n , I E C 6 1 8 5 0 h a s e sta b lish e d itse lf a s g lo b a l sta n d a rd fo r su b sta tio n a u to m a tio n . A n e x a m p le fro m S witze rla n d is th e syste m in sta lle d in S ils ➔ 1 [2 ]. T h is is, h o we ve r, fa r fro m th e c o n c lu sio n o f its d e ve lo p m e n t. A d d itio n a l a p p lic a tio n a re a s a re b e in g c o n sid e re d b y I E C . T h e sta n d a rd is th u s b e in g e x te n d e d . From substation autom ation to pow er utility autom ation IEC 61850 Edition 2 4 8 A B B review special report These extensions do not only concern the application-data m odel itself, but also the capabilities of the S C L (substa- tion configuration language) to support new data m odels and enhanced engi- neering processes. R e m a i n i n g c h a lle n g e s fro m E d i ti o n 1 61850-9-2 defines the standardized com m unication of current and voltage sam ples across an Ethernet-based serial link. B esides transm itting such analog sam ples, the link also transm its sw itch positions, com m ands and protection trips. A ccording to IEC 61850-8-1, this com bination results in a com plete pro- cess bus betw een prim ary and second- ary equipm ent➔ 3 . The response tim e and throughput re- quirem ents on this bus are determ ined m ainly by the sam ples. The advantages of such a process bus are: –It perm its the replacem ent of m any copper cables by a few optical cables (low er cabling costs) –O ptical cables achieve the galvanic decoupling of prim ary and secondary equipm ent (m akes m aintenance and replacem ent easier). –The serial interface m akes the applica- tions independent of the physical principle of the instrum ent transform er (electrom agnetic, capacitive, optical, others) allow ing m ore flexibility on the prim ary equipm ent side. Edition 1 of the standard did not define a solution for the tim e synchronization re- quired for the com m unication of sam ples at rates in the region of m icroseconds. Therefore, and to achieve the accep- tance of a faster process bus, the user organization, U C A International [11], de- veloped an application recom m endation know n as IEC 61850-9-2LE (Light Edi- tion). This recom m endation is based on the concept of a m erging unit (M U ) that delivers all current and voltage sam ples changes. In m any cases, only a subset of them is needed. –The basic substation-autom ation related data m odel has to be extend- ed only by additional logical node classes needed for functions from these other dom ains. –The com m unication stack used is very com m on (especially TC P /IP and Ethernet). T h e s ta n d a rd e x te n d s b e y o n d th e s w i tc h y a rd There is a signi cant advantage for utili- ties if data from substation IED s can be used directly on higher system levels for control and m onitoring purposes, w ithout there being a need for protocol converters or having to handle num erous different protocols. Therefore tw o w orking groups of IEC TC 57 have looked at the use of IEC 61850 for real-tim e applications such as line protection and also other applica- tions that involve com m unication betw een substations as w ell as m onitoring and control applications involving com m uni- cation betw een substations and netw ork control centers. The results w ill be pub- lished as technical reports. The report that handles com m unication betw een substations is published as IEC TR 61850 90 1 [8]. Its results are being integrated into the second edition of the base standard. B esides discuss- ing direct tunneling of Ethernet-level m essages on high-bandw idth links, it also looks at the usage of proxy gate- w ays w ith low -bandw idth links ➔ 2 . The report handling com m unications betw een substations and netw ork con- trol centers w ill be published as IEC TR 61850-90-2 [9] and any resulting add- ons to the base standard w ill be integrat- ed into an am end- m ent to Edition 2, or at the latest in Edition 3 of the base standard. W ork on a third re- port handling the autom ated trans- form ation and m ap- ping betw een the IEC 61850 data m odel and the IEC 61970 C om m on Inform ation M odel (C IM , [10]) has just begun. T he developm ent of the IEC 61850 standard is con- tinuing. This w ork is prim arily aim ed at rem edying various shortcom ings that w ere identified during the first installations, but it also seeks to enhance its application range –as is re- flected in its changed title “C om m unica- tion N etw orks and S ystem s for P ow er U tilities”[3]. This w ork is resulting in Edi- tion 2 of the standard, w hich is being published in 15 parts during 2010. E x p a n d i n g i n to n e w a p p li c a ti o n a re a s IEC 61850 w as originally defined exclu- sively for substation autom ation system s (including protection applications). It has since been extended to other application areas. These are autom ation of w ind pow er system s [4], hydro pow er system s [5], and distributed energy resources such as com bined heat and pow er sys- tem s or photovoltaic plants [6]. The fact that the standard is being applied in the dom ain of distributed energy resources indicates the significance of IEC 61850 for sm art grids. A spects of the extension of IEC 61850 to these dom ains include the follow ing: –The services of IEC 61850 have been proven to fulfill the know n require- m ents of these other dom ains and m ay hence be applied w ithout IEC 61850 w as originally defined exclusively for substa- tion autom ation system s, but has since been extended to other application areas. 4 9 I E C 6 1 8 5 0 E d i ti o n 2 the conventional current transform er of type TP Y for protection. This allow s the type testing of the com bined set of N C IT and M U . This has been done success- fully for A B B ’s N C IT C P, (com bined cur- rent and voltage sensors for G IS ) w hich are now ready for use. S om e questions rem ain unresolved, es- pecially how the signal from a conven- tional transform er (C IT) is changed due to digitalization in the M U . These ques- tions are addressed by the IEC TC 38 (In- strum ent Transform ers) that has started replacing IEC 60444 by new standard IEC 61869 [14] in a step by step m anner. It w ill define in its part 9 the “digital inter- face”covering the w hole issue of M U s. The result w ill not be available in tim e to be referenced in Edition 2 of IEC 61850. S everal m anufacturers are already offer- ing M U s as pilot products. H ow ever, the electronic interface to a sw itch (often called a breaker IED or B IED ) is rare even as a pilot product. S om etim es “norm al” controllers are used in a sim ilar w ay to B IED s, eg, by receiving G O O S E (G eneric O bject O riented S ubstation Event) trips from protection devices. This can for ex- from a given bay in a tim e-synchronized m anner. It defines a telegram form at containing voltages and currents from the three phases and the zero com po- nents. It specifies tw o sam ple rates (80 and 256 sam ples per period) and a tim e synchronization by a pulse per second (1 pps) w ith a synchronization accuracy class of T4 (± 4 µs). M eanw hile, a profile of the standard IEEE 1588 [12] is being w orked on, w hich w ill support high-pre- cision tim e synchronization across sw itch-based Ethernet. The num erous features and benefits that the process bus offers are considered in a discussion on optim al processes in connection w ith com m unication archi- tecture. The interoperable application has been delayed, how ever, because the dynam ic behavior (step and frequency response) of the sam ples has not been sufficiently defined to guarantee applica- tion-level interoperability. The behavior of conventional instrum ent transform ers is defined in the standard IEC 60044 [13] as is the behavior of electronic current and voltage transform ers, thus sum m arizing all N C ITs. It is stated, eg, that the elec- tronic current transform er behaves as M ore com ponents w ill facilitate the adoption of the architecture of the S A system and perm it the better physical distribu- tion of the prim ary equipm ent, provid- ing the full advan- tage of the process bus. 1 I E C 6 1 8 5 0 b a s e d s u b s ta ti o n a u to m a ti o n s y s te m i n S i ls . T h i s i m p le m e n ta ti o n i s a ls o d i s c u s s e d o n p a g e 3 8 . Engineering w orkstation S tation H M I R em ote control G P S R edundant gatew ays B ackup (N A S ) S tation server Ethernet sw itch R S G 2100 B ay side Ethernet sw itch R S G 2100 Transform er 1 Ethernet sw itch R S G 2100 Transform er 2 R EC 670 M W U 380 kV B B P 380 kV line 1 380 kV coupler 380 kV transform er 2 380 kV line 2 380 kV transform er 1 M W U M W U M W U D S A S -R TU R EC 670 R EC 670 R EC 670 R EC 670 7S A 612 7S A 612 7S A 612 7S A 612 7S A 612 R EL670 R EL670 R EL670 R EL670 R EL670 S IM EA S R S IM EA S R S IM EA S R S IM EA S R S IM EA S R R EB 500 B U R EB 500 B U R EB 500 B U R EB 500 B U R EB 500 B U B C M 800 B C M 800 B C M 800 B C M 800 B C M 800 L+G ZM Q L+G ZM Q L+G ZM Q L+G ZM Q L+G ZM Q B B P /B FP central unit R EB 500 5 0 A B B review special report verified that the Edition 1 devices used already im plem ent resolutions of all tech- nical problem s identified up to Edition 2. This can be done by m eans of the so called TIC S docum ent, w hich should be available from the m anufacturer for each certified IED type. B e y o n d E d i ti o n 2 IEC standards are being developed in a tim e-consum ing procedure involving com m enting and voting by the national com m ittees in several steps and via dif- ferent drafts as they w ork tow ards the final international standard (IS ). There- fore, som e task forces have already started w ork on topics for am endm ents or for a future Edition 3, w hich w ill fulfill further user requirem ents. S om e of the topics being considered are: –Ethernet netw ork architectures w ithin substations including redundancy and Ethernet sw itch configuration. –A setup for the supervision and diagno- sis of prim ary equipm ent, called C M D (condition m onitoring and diagnosis). To provide an overview of the standard’s fast-grow ing data m odel for both present and future application dom ains, and to be able to realize extensions m ore quick- ly than is possible in the norm al stan- dardization process, the introduction of an IEC database for m odel definitions is under discussion. This w ould be acces- sible via Internet. A standardized form al description of the m odel definitions de- fined in Edition 2 w ill help w ith the rapid integration of new m odels into the tools. I E C 6 1 8 5 0 a n d S m a rt G ri d s The discussion around the future of the pow er grid w ith m ore and m ore decen- tralized pow er generation, flexible pow er buying and high grid reliability often labels this objective as “sm art grid”. A n as- am ple be used for the tw o affected breakers of a 1 ½ breaker sw itchyard di- am eter, or for breaker failure protection. There are also ideas to com bine a M U and a B IED into one product. H ow ever, this is not a m atter for IEC 61850 but for the optim ized application of the process bus. The benefits of process bus appli- cations can already be reaped today. M ore com ponents w ill facilitate the adop- tion of the architecture of the S A system and perm it the better physical distribu- tion of the prim ary equipm ent, providing the full advantage of the process bus. I E C 6 1 8 5 0 E d i ti o n 2 B esides the correction of errors and m any sm all details, Edition 2 w ill contain the add-ons laid out in ➔ 5 . It is planned to publish all parts of Edition 2 w ith the exception of 7-5xy as an inter- national standard during the course of 2010. The question of w hen correspond- ing tools and products w ill appear on the m arket depends on the m anufacturers and appropriate requirem ents from cus- tom ers and is difficult to predict. A ll error corrections, clarifications and restrictions contained in Edition 2 w ith respect to Edition 1, how ever, should already be follow ed by the next releases of Edition 1 devices. In this context it should also be m entioned that it is possible to use Edi- tion 2 engineering and S C L descriptions w ith IED s still having an Edition 1 data m odel. Edition 2 and all follow ing edi- tions w ill be backw ards com patible to Edition 1 (w ith the exception of error cor- rections). A custom er or supplier today deciding to apply IEC 61850 Edition 1 w ill thus benefit from all present advan- tages and future benefits of this stan- dard. To assure as m uch com patibility to future editions as possible, it should be 3 P ro c e s s b u s w i th m e rg i n g u n i t ( M U ) , s w i tc h i n te rfa c e ( B I E D ) a n d e x te rn a l E th e rn e t s w i tc h Fiber optical S tation bus C urrents (I) Voltages (U ) Fiber optical P rocess bus P rotection trip S econdary equipm ent P rim ary equipm ent I E D P rotection Trip decision M U M erging U nit B I E D B reaker Interface 2 C o m m u n i c a ti o n p ri n c i p le s b e tw e e n s u b s ta ti o n s b a s e d o n I E C 6 1 8 5 0 Function A 1 Function A 2 S tation A P roxy B 2 Function A 1 Function B 2 S tation B S pecial C om m unication M echanism (typically low bandw idth) “Teleprotection Equipm ent” acting as G atew ay IEC 61850-90-1 It is possible to use Edition 2 engi- neering and S C L descriptions w ith IED s still having an Edition 1 data m odel. 5 1 I E C 6 1 8 5 0 E d i ti o n 2 [9] IEC /TR 61850-90-2, C om m unication netw orks and system s for pow er utility autom ation –P art 90-2: U se of IEC 61850 for the com m unication betw een substation and netw ork control center, in w ork [10] IEC 61970-301, Energy m anagem ent system application program interface (EM S -A P I) –P art 301: C om m on Inform ation M odel (C IM ) B ase, 2003-11 [11] IEC 61850-9-2LE (Light edition) Im plem enta- tion G uideline for D igital Interface to Instrum ent Transform ers using IEC 61850-9-2, U C A International U sers G roup, w w w .ucainterna- tional.org [12] IEEE 1588, P recision C lock S ynchronization P rotocol for N etw orked M easurem ent and C ontrol S ystem s [13] IEC 60444 Instrum ent transform ers [14] IEC 61869, Instrum ent transform ers –P art 1: G eneral requirem ents, 2007-10 (others parts in w ork) [15] Electric P ow er R esearch Institute (EP R I), R eport to N IS T on the S m art G rid Interoper- ability S tandards R oadm ap, June 17, 2009 (w w w .nist.gov/sm artgrid ) R e fe re n c e s [1] IEC 61850 (Ed 1), C om m unication N etw orks and S ystem s in S ubstations, 14 P arts, 2003-2005, http://w w w .iec.ch. [2] B rand, K .P, R einhardt, P, 2008, Experience w ith IEC 61850 based S ubstation A utom ation S ystem s, P raxis P rofiline –IEC 61850, 66-71 [3] IEC 61850 Ed 2, C om m unication N etw orks and S ystem s for P ow er U tility A utom ation, scheduled for 2010, http://w w w .iec.ch [4] IEC 61400-25-x, W ind turbines –P art 25-1: C om m unications for m onitoring and control of w ind pow er plants, 2006-12 [5] IEC 61850-7-410, C om m unication netw orks and system s for pow er utility autom ation –P art 7-410: H ydroelectric pow er plants –C om m uni- cation for m onitoring and control, 2007-08 [6] IEC 61850-7-420, C om m unication netw orks and system s for pow er utility autom ation –P art 7 420: B asic com m unication structure –D istri- buted energy resources logical nodes, 2009-03 [7] S w iss C hapter of IEEE P ES , H ydro P ow er W orkshop I (H andeck, 2008) und W orkshop II (G enf, 2009), http://pes.ieee.ch [8] IEC /TR 61850-90-1, C om m unication netw orks and system s for pow er utility autom ation –P art 90-1: U se of IEC 61850 for the com m unication betw een substations, to be published sum m er 2009 sum ed prerequisite to the functioning of such a grid is that m ore inform ation can be m ade available in a reliable and tim ely m anner to m ore and m ore distributed ap- plications and users, perm itting control to be optim ized. This w ill assure the grid’s stability, m ake electrical energy available w here needed, and perm it interactive com m unication w ith consum ers. This re- quires the needed data to be m ade avail- able w ithin a com m on inform ation net- w ork and according to standardized data sem antics. This is precisely w here IEC 61850 fits in. Therefore IEC 61850 has been taken up alongside IEC 61970 in a sm art-grid related report from EP R I [15] and adopted by N IS T as a key interest. K la u s -P e te r B ra n d Wo lfg a n g Wi m m e r A B B S ubstation A utom ation B aden, S w itzerland klaus-peter.brand@ ch.abb.com w olfgang.w im m er@ ch.abb.com 5 a E x a m p le fo r s ta ti s ti c a l m e th o d s ( C lc M th ) a p p li e d o n M M X U 5 I E C 6 1 8 5 0 E d i ti o n 2 M M X U 1 TotW Total A ctive P ow er TotVA r Total R eactive P ow er TotVA Total A pparent P ow er TotP F Average P ow er Factor P P V P hase to phase Voltages V P hase to ground Voltages A P hase C urrents ....................................... TotW Total A ctive P ow er TotVA r Total R eactive P ow er TotVA Total A pparent P ow er TotP F Average P ow er Factor P P V P hase to phase Voltages V P hase to ground Voltages A P hase C urrents ....................................... P R ES TR U E_R M S P EA K _FU N D A M EN TA L R M S _FU N D A M EN TA L M IN M A X AVG S D V P R ED IC TIO N R ATE ...... M M X U 2 C lc M th 5 b M a n a g e m e n t h i e ra rc h y fo r lo g i c a l d e v i c e s I E D 1 G rR e f = I E D 1 . O c p . L L N 0 O c p LLN O O c p G n d O c p P h s P TO C 1 P TO C 1 R D IR 1 R D IR 1 LLN O LLN O B esides the correction of errors and m any sm all details, Edition 2 of IEC 61850 w ill contain the follow ing add-ons: – C la ri fi c a ti o n s o f u n c le a r p a rts such as: – buffered reporting – m ode sw itch (test m ode) – control access hierarchy (local / rem ote) – D a ta m o d e l a n d S C L e x te n s i o n s fo r c o m m u n i c a ti o n b e tw e e n s u b s ta ti o n s : discussed above and outlined in ➔ 2 – S u p p o rt fo r re d u n d a n t I E D i n te rfa c e s : discussed in "S eam less redundancy”on pages 57-61 of this ABB Review S pecial R eport. – D a ta m o d e l e x te n s i o n s fo r n e w a p p li c a ti o n fu n c ti o n s : supervision of non electrical quantities, etc. (These new logical nodes have been m ainly introduced by other application dom ains such as hydro-pow er plants) – S ta ti s ti c a l e v a lu a ti o n s o f m e a s u re m e n ts a s c o n ta i n e d i n th e lo g i c a l n o d e s M M X U a n d M M X N : Triggered by pow er-quality discussions and other application dom ains such as w ind pow er ➔ 5 a . – S u p p o rt fo r tra c k i n g a n d lo g g i n g o f s e rv i c e s a n d s e rv i c e re s p o n s e s : This feature m akes service param eters and service handling visible w ithout the use of protocol analyzers by the standard’s existing reporting and logging facilities and allow s, eg, the logging of negative answ ers on service requests (negative acknow ledgem ents). This feature is useful both for com m issioning and security supervision. – M a n a g e m e n t h i e ra rc h i e s o f lo g i c a l d e v i c e s : Especially com plex m ultifunctional protection IED s require m ore functional levels for the m anagem ent of com m on param eters. For an exam ple see ➔ 5 b : The logical device O cp controls the m ode of the low er level logical devices O pcP hs and O pcG nd by group reference (G rR ef) w hich additionally could be controlled individually. – N e w d a ta o b je c ts a n d c o n c e p ts fo r te s ti n g o f fu n c ti o n p a rts i n th e ru n n i n g s y s te m : This feature allow s now a standardized application of the test and test-blocked m ode w hich w as already introduced in Edition 1 and is now clarified in Edition 2. It supports the handling of test m essages in parallel to the real m essages. – S C L e x te n s i o n s to d e s c ri b e n e w I E D p ro p e rti e s a n d b e tte r s u p p o rt o f e n g i n e e ri n g p ro c e s s e s a n d re tro fi t: The data exchange betw een different projects in a controlled w ay allow s coordinated engineering in parallel running subprojects. – S C L i m p le m e n ta ti o n c o n fo rm a n c e s ta te m e n t ( S I C S ) : stating m andatory and optional features of IED tools and system tools. This feature allow s judging the degree of interoperability betw een different engineering tools, system tools as w ell as IED tools. – A n i n fo rm a ti v e p a rt 7 -5 x w i th e x a m p le s o f m o d e li n g i m p o rta n t a p p li c a ti o n fu n c ti o n s i n th e s y s te m : This part is intended to support com m on understanding of m odeling and to m ove tow ards broadly accepted m odeling solutions 5 2 A B B review special report 5 3 R e li a b le n e tw o rk i n g K L A U S -P E T E R B R A N D , WO L F G A N G WI M M E R – T h e c o m m u n i c a ti o n s ta n - d a rd I E C 6 1 8 5 0 w a s i n tro d u c e d to s ta n d a rd i z e th e c o m m u n i c a ti o n fo r s u b s ta ti o n a u to m a ti o n s o th a t a ll d e v i c e s , n o m a tte r th e i r o ri g i n , c o u ld c o m m u n i c a te u s i n g a s ta n d a rd p ro to c o l re p la c i n g w i re s w i th s e ri a l c o m m u n i c a ti o n . B a s e d o n m a i n s tre a m c o m m u n i c a ti o n te c h n o lo g y, li k e th a t o f th e E th e rn e t, I E C 6 1 8 5 0 b e n e ts fro m a h i g h d e g re e o f fl e x i b i li ty w i th re g a rd to c o m m u n i c a ti o n a rc h i te c tu re . A n y s o lu ti o n , h o w e v e r, h a s to fu l ll s tri n g e n t re li a b i li ty re q u i re m e n ts to e n s u re a c o n s ta n t p o w e r s u p p ly i n tra n s m i s s i o n a n d d i s tri b u ti o n g ri d s to a c c o m p li s h th e s a fe ty -c ri ti c a l m i s s i o n o f s u b s ta ti o n a u to m a ti o n . M a i n s tre a m E th e rn e t c o n n e c ti o n s d o n o t n e c e s - s a ri ly p ro v i d e th e re q u i re d re li a b i li ty. T h e I E C 6 1 8 5 0 re a c h e s th e re q u i re d le v e l o f c o m m u n i c a ti o n re li a b i li ty fo r s u b s ta ti o n a u to m a ti o n b y c o n g u ri n g a p p ro p ri a te m e s s a g e lte ri n g a n d c h e c k i n g th e lo a d fo r w o rs t c a s e a p p li c a ti o n s c e n a ri o s fo r ti m e c ri ti c a l c o m m u n i c a ti o n tra f c . Im pact of m odern com m unication technology on system reliability R eliable netw orking include the m axim um allow ed response tim e for an action. Ethernet w as origi- nally designed to be tolerant of failures, but not to guarantee response tim es. Therefore for this purpose special rules m ust be applied so that the Ethernet can be used for tim e critical application func- tions. F a i lu re m o d e s a n d s e rv i c e s A failure m eans that som e com ponent in the S A system is not w orking as intend- ed, w hich im pacts the functionality of the S A system . Failures can be perm anent or tem porary. Failures produce errors in the intended system functionality. The result of a perm anent failure m ay be the loss of pow er supply, loss of processing elec- tronics, or loss of com m unication ports, like failing diodes for fiber optic links. These kinds of errors can be accom m o- dated by appropriate redundancy strate- gies as discussed in the context of com - m unication in the previous article (see "S eam less redundancy" on page 57 of this issue of the ABB Review S pecial R eport). O ften, especially in the context of com - m unication, tem porary errors can occur as a result of electrom agnetic distur- bances or the interm ittent failure of com - ponents. These m ay be caused by tem - perature fluctuations, the distortion of S ubstation autom ation (S A ) is com m only used to control, protect and m onitor substa- tions [1]. U p to now , the com - m unication for S A has used proprietary serial com m unication system s com ple- m ented by conventional parallel copper w iring, especially from the bay level to the sw itchgear. W ith the advent of IEC 61850 [2], a com prehensive global standard for all com m unication needs in the substation is available. The reliability of S A com m unication ar- chitectures is of great im portance for the reliability of the pow er supply from the pow er transm ission and distribution grid. U p until now a dedicated com m unica- tion system has been used, how ever the IEC 61850 uses a standard m ainstream com m unication m eans like Ethernet, w hich provides a high degree of flexibili- ty, but does it bring reliability? R eliability according to IEC 60870-4 [3] is defined as a m easure of the equipm ent or a system to perform its intended func- tion, under specified conditions, for a specified period of tim e. O ften investiga- tions concentrate on reliability w ith re- gard to hardw are faults. In the case of tim e-critical functions, like protection or load shedding based on serial com m uni- cation, the “specified conditions’also 5 4 A B B review special report the delay, w hich for a 1,000 B yte (8 kB it) m essage and 100 M B it / s Ethernet, equates to about 100 µs. This is typically m uch m ore than the routing tim e w ithin a sw itch. A ssum ing a ring w ith 20 sw itch- es, for exam ple, an additional delay of 2 m s can occur betw een sender and receiver. IP -based traffic norm ally has a deter- m ined destination. Thus a sw itch can learn to route a corresponding Ethernet m essage to a particular port, as show n in ➔ 2 . The disadvantage of this point to point traffic is that the sender has to send separate m essages to each intended re- ceiver. For real-tim e m essages there is often m ore than one receiver of the sam e m essage. The interlocking function, for exam ple, needs the state (sw itch posi- tions) of the bus coupler at all bay con- trollers of all bays at the sam e voltage level. Therefore, the G O O S E and S V ser- vices use Ethernet-level m ulticast ad- dresses. These configurable, hardw are- independent link level addresses also m ake m aintenance easier. A s a sw itch does not know w here the receivers of m ulticast m essages are, it typically for- w ards the m essages to all devices con- nected to it, thus producing a lot of pos- sibly unw anted load for the receivers. C onsidering the interlocking function for 30 bays, w here each bay sends the state of its busbar related prim ary sw itches to all other bays in the sam e voltage level w ith a background period of 1 s, this re- sults in a background load of 30 m es- sages per second. This load is needed at the controllers, how ever not at the pro- tection devices, w hich instead m ight need other G O O S E m essages eg, for the breaker failure function. To separate w anted load from unw anted load, Ethernet sw itches support the con- cept of m ulticast m essage filtering. This can be based on m ulticast addresses as The G O O S E service is m eant for fast sending of process state changes (events). Therefore, to overcom e tem po- rary errors on single m essages, the m es- sage is repeated in case a value in the G O O S E m essage changes a few tim es very quickly (eg, w ithin 4 m s intervals). A fter this, a fall back to the periodic background period occurs in the order of a second (see “The concept of IEC 61850” on page 7 of this issue of the ABB Re- view S pecial R eport). The tim e span be- tw een three or four fast sendings is a configuration param eter, w hich typically depends on the m axim um tolerable delay. These services can be used for protec- tion and other safety related functions [4]. E th e rn e t s p e c i fi c c h a lle n g e s Ethernet w as originally developed as a bus system , in w hich several devices are coupled to a com m on com m unication m edium . This m echanism leads to colli- sions if tw o devices try to send data at the sam e tim e ➔ 1 . D ue to such colli- sions, the response tim es during burst situations are un- predictable, and the m axim um through- put is less than 10 to 20 percent of the raw bit rate of the bus. This is over- com e by using Ethernet sw itches w ith duplex connections betw een them and to the end devices. S w itches w ork w ith a “store-and-for- w ard”principle like IP level routers ➔ 2 . They receive a m essage com pletely, and then forw ard it to the know n output port, thereby avoiding m essage collisions com pletely by prioritizing m essages w ithin the sw itches. The disadvantage of sw itched Ethernet is, that each hop from one respective sw itch to another adds to optical cables that have been bent too m uch or sim ilar, leading to tem porarily disturbed or m issed m essages in the com m unication system . These kinds of failures are typically detected by high- level protocols like transm ission control protocol (TC P ), and are handled by tell- ing the sender about a m issed m essage and then repeating its dispatch. For this reason all IEC 61850-based com m unica- tions, w hich are not tim e critical, are built on the TC P protocol. To allow additional routing in arbitrary com m unication net- w orks, TC P runs on top of the Internet netw orking protocol (IP ). U nfortunately, the handling of m essage errors through repetition results in further m essage delays. The detection of a failed m essage and its repeated dispatch in TC P is based on an acknow ledgem ent m echanism w ith tim eouts that m ay lead to delays in the order of seconds. H ow - ever, the acceptable m axim um delay for a tim e critical application function is in the order of 10 m s to 100 m s. TC P - based services, therefore, are not suit- able for m any autom ation and protection functions. For this reason IEC 61850 in- troduces the G O O S E (generic object ori- ented system event) and S V (sam pled value) services for functions needing real-tim e perform ance. B oth services are directly m apped onto the Ethernet link layer. B oth periodically send sequentially num bered m essages, w hich allow a re- ceiver to detect m issing m essages as w ell as perm anent failures. S am pled val- ues are transm itted w ith a high rate cor- responding to the sam pling rate of cur- rents and voltages, eg, 80 m essages per cycle being 4,000 m essages / s for a 50 H z system , thus replacing a m issed sam ple by the next one very quickly. It is up to the receiving application to handle single lost values, eg, by interpolating the received w ell-know n ones already from any A /D conversion. The reliability of S A com m uni- cation architectures is of great im portance for the reliability of the pow er supply from the pow er transm ission and distribution grid. 1 C o lli s i o n o n a b u s w i th h u b s collision m e s s a g e m e s s a g e IED IED H ub IED IED IED 2 S w i tc h e s w i th “ s to re -a n d -fo rw a rd ” IED IED IED IED IED S w itch H op 2 H op 1 m e s s a g e 5 5 R e li a b le n e tw o rk i n g 3 L o g i c a l d a ta flo w i n a s m a ll s y s te m P 2K A 1 R EC 316-4 P 2W A 1 Interlock S tatU rgC 1 S tatU rgM 1 M easFlt P ositions S tatU rg M M XU 1U R ptM xD s Interlock P rotTrip G ooseS t D ataS et1 Interlock P 2FA 1 R EL 316-4 P 2W A 1 P 2K A 3 Siprotec-7SJ6xx P 2W A 1 P 2K A 2 C 264 P 2W A 1 P 2K A 4 R EC 316-4 P 2W A 1 Interlock S tatU rg P 2Y1 C O M 581 ***G W *** are lost due to insufficient buffer space. These challenges can be tackled w ith appropriate tools. The IEC 61850 data flow allow s the intended destinations for all kinds of m essages to be described, thus defining the required data flow at the application level. A n exam ple for G O O S E (green) and TC P based (blue) data flow is show n in ➔ 3 . The load situa- tion based on the presum ed data flow can be determ ined easily at each receiv- er in norm al and burst situations ➔ 4 . C om paring this w ith the input capacity of the devices gives a quick check as to w hether the intended function distribu- tion and data flow at application level is reasonable and w ill w ork from a com m u- nication point of view . The boxes in ➔ 3 represent intelligent electronic devices (IED s), w hose nam es are w ritten in the first line, and w hich all com m unicate w ithin the S ubN etw ork P 2W A 1 (third line in each box). The IED s P 2K A 1, P 2K A 2, P 2K A 3 and P 2K A 4 are controllers sending G O O S E m essages for interlocking to each other. The IED P 2FA 1 is a protection device, w hich sends a trip w ith G O O S E to the control- ler P 2K A 1 to trigger a disturbance re- corder. The IED P 2Y1 is a gatew ay to a netw ork control center, w hich receives reports from all other devices. ➔ 4 show s the load calculated from a substation configuration language (S C L) description of this system for all receiv- ers based on the configured data flow . This results in the required load for a sw itch netw ork that is correctly config- ured. If the allow ed m essage input rate to an application IED is know n, it can be checked if the application w ould really w ork. ➔ 5 now contains the calculated load based on the configured virtual local area netw ork (VLA N ) identifications. B y com parison w ith ➔ 4 it can be easily seen that this configuration using m ainly VLA N 000, ie, no VLA N , leads to a suboptim al situation. Even the gatew ay P 2Y1, w hich should only receive reports and does not belong to any VLA N , is loaded w ith G O O S E m essages, and the protection device P 2FA 1, w hich should receive nothing, gets 3 G O O S E m essages / s. For this sm all system the resulting load, even during a burst, is no problem at all. H ow ever, for a bigger system a better VLA N configuration should be used to To a certain extent this can be handled by the Ethernet priority feature. TC P - based tim e uncritical traffic has no prior- ity and can also be delayed by appropri- ate configuration at the sender by 50 to 200 m s. G O O S E and S V traffic gets pri- ority in the sw itches and is put first into the output m essage queues. Thus it is not delayed by TC P traffic, just by other G O O S E and S V m essages. To sum up: –The IEC 61850 usage of sw itched Ethernet for tim e critical applications can guarantee m axim um response tim es dow n to a few m illiseconds. –To reach this perform ance and also to restrict unw anted load on the end devices, the Ethernet m ust be built w ith duplex connections to and betw een m anaged sw itches, ie, sw itches supporting priorities and VLA N or m ulticast address-based filtering. –It is necessary to configure priorities, VLA N ID s and m ulticast addresses at the G O O S E and S V sources as w ell as appropriate m essage filtering at the sw itches for the intended high- perform ance m ulticast data flow . S o lu ti o n s to re m a i n i n g p ro b le m s Tw o m ain challenges rem ain: –C onfiguring VLA N or M ulticast filtering into the sw itches –A ssuring that for big system s the m axim um delay in the sw itch netw ork fits w ithin the required m axim um response tim e, and that no m essages w ell as on the introduction of virtual LA N s (VLA N ). Therefore, IEC 61850 introduces a separately configurable m ulticast ad- dress as w ell as a separate VLA N identi- fication for each G O O S E or S V m essage source. This leads to additional engineer- ing effort to identify the flow of m ulticast m essages from the source to all intended destinations through the sw itch netw ork and to configure the concerned sw itches accordingly. A nother challenge, w ith the store-and- forw ard principle of sw itches, is the re- lated interm ediate buffering (storing) of m essages in case of bursts. In such a situation, a lot of m essages from differ- ent input ports arrive at a sw itch, w hich typically has to be forw arded through a single output port eg, to the station level. If the inputs of 10 ports are routed to one output port w ith the sam e bit rate, then nine m essages have to be buffered in betw een. This leads to additional m es- sage delays, and in extrem e cases m ay result also in m essage losses due to in- sufficient buffer capacity. It should be kept in m ind that the reliabil- ity of G O O S E m essages depends on the prerequisite that not m ore than tw o con- secutive m essages are lost. This prereq- uisite has been validated by a lot of tests based on physical disturbance scenari- os. H ow ever, if in a busbar trip situation, G O O S E m essages are lost in the sw itch- es due to insufficient buffer size, delayed G O O S E-based actions m ay result. G O O S E traffic TC P traffic 5 6 A B B review special report This bottleneck can be easily found by just analyzing the receiver load for nor- m al data flow based on the S C D file ➔ 4 . This kind of analysis is recom m ended for a system w ithout process bus, if it han- dles m ore than 30 bays. The trend to put m ore and m ore devices to 100 M B it / s Ethernet w ill m ake this analysis m ore and m ore urgent, since it is the receiving end devices that have the bottlenecks and not the com m unication system itself. To conclude, netw orking can be highly re- liable for substations and utility autom a- tion is possible using m odern m ain stream com m unication technology, such as Eth- ernet, in accordance w ith IEC 61850. K la u s -P e te r B ra n d Wo lfg a n g Wi m m e r A B B S ubstation A utom ation B aden, S w itzerland klaus-peter.brand@ ch.abb.com w olfgang.w im m er@ ch.abb.com R e fe re n c e s [1] B rand, K .P., Lohm ann, V., W im m er, W . (2003) S ubstation A utom ation H andbook, U A C . IS B N 3-85759-951-5. R etrieved June 6 2010 from w w w .uac.ch [2] IEC 61850 (2002 2005) C om m unication netw orks and system s in substations. R etrieved June 6, 2010 from w w w .iec.ch [3] IEC 60870-4 (1990) Telecontrol equipm ent and system s; P art 4 –P erform ance requirem ents. R etrieved June 6, 2010 from w w w .iec.ch [4] B rand, K .P., O stertag, M ., W im m er, W . (2003) S afety related distributed functions in S ubstations and IEC 61850. IEEE B P T B ologna, P aper 660 [5] IEC 61850-6Ed2 (2009) C om m unication netw orks and system s for pow er utility autom ation –P art 6: C onfiguration description language for com m unication in electrical substations related to IED s. R etrieved June 6, 2010 from http://electronics.ihs.com delays in w orst case situations. The m ain problem here is to know w hat are the w orst case situations seen from the pro- cess point of view , and how do they m anifest them selves in m essage load for the devices hosting application func- tions. O ne typical scenario is a busbar trip, resulting in a change of all m easure- m ents and the tripping of all circuit break- ers w ithin a very short tim e span, w ith the addition of 10 alarm s from the sw itch- yard or protection system . O ther scenar- ios depend on the sw itch yard configura- tion and its place in the pow er netw ork and m ust be defined by the utilities. If these scenarios and the resulting m es- sage load are know n, the system de- scription as IEC 61850 S C L file allow s for a tool to determ ine the resulting m es- sages and their flow to the end devices as illustrated above. W ith a description of the physical structure, the flow through the sw itch netw ork m ay be calculated also; this includes the required m axim um buffer size to ensure that no m essage is lost, as w ell as the m axim um delay in the output queues. This allow s the m axim um G O O S E and S V m essage delay to be de- term ined in advance, and the buffer size of the sw itches to be check against their required size. If this is not consistent, then redesigning the com m unication ar- chitecture m ight be a solution. M ore buf- fer space in the sw itches m ight be re- quired, or in the w orst case the application im plem entation itself m ay need to be changed to reduce the com m unication load required. H ow ever, these kinds of problem s only arise in very big system s or system s w here S V m essages are used betw een several bays. It is com m on today in big system s w ithout process bus and only a few G O O S E-based functions to find bot- tle necks typically at the station level de- vices, m ay be at the hum an m achine in- terface (H M I), or m ay be at the gatew ay. get closer to the m inim um m essage rate needed for the application level engi- neering as show n ➔ 4 . In a ring netw ork, the filtering configura- tion at the sw itches can be derived from the logical data flow . To avoid filter recon- figuration in case of sw itch ring reconfig- uration, the filtering should only be con- figured for the receiving devices or betw een different rings, w hile all ports betw een sw itches should allow all used VLA N s. The filter to the receiving devices can be autom atically calculated together w ith the receiver load. A s an exam ple ➔ 5 contains the VLA N identifications, w hich should be configured at the sw itches to be sent to the port w here the correspond- ing device is connected. A s VLA N 000 just m eans “ignore the VLA N and send everyw here”, here the only thing to be configured is the VLA N 001 as output to the device P 2K A 4. In a sim ilar w ay a re- lated configuration for filtering based on m ulticast addressing can be generated. For tree netw orks a sim ilar strategy could be used. H ow ever, if w ithin the tree netw ork appropriate filtering is also needed, an additional form al description of the physical netw ork, as defined in IEC 61850-6 Ed2 [5], also perm its the sw itch filter configuration to be autom at- ically derived from the logical data flow . Finally the configuration data m ust be m anually loaded into the sw itches (differ- ently per sw itch m anufacturer). This should change in the future, since IEC TC 57 W G 10 is w orking on a standard- ized sw itch configuration description in S C L, w hich should then be used as input to sw itch engineering tools. The form al description of the physical structure also supports handling of the last problem : probable m essage loss due to insufficient buffer size and additional 4 E x p e c te d lo a d a t re c e i v e rs d u e to c o n fi g u re d d a ta flo w R eceived load per IED based on client allocation IED nam e kB it/s M sgs/s B urst m sgs P 2K A 1 11 2 6 P 2K A 4 16 2 9 P 2K A 2 10 1 3 P 2K A 3 10 1 3 P 2Y1 5 5 25 5 A c tu a l lo a d i n n o rm a l s i tu a ti o n d u e to c o n fi g u re d VL A N s R eceived S V/G O O S E load per IED due to VLA N config, and VLA N list IED nam e kB it/s M sgs/s B urst m sgs VLA N ID s P 2K A 1 12 2 9 000 P 2K A 4 17 2 12 001 000 P 2K A 2 21 3 9 000 P 2K A 3 22 3 12 000 P 2FA 1 21 3 9 P 2Y1 22 3 12 5 7 S e a m le s s re d u n d a n c y H U B E R T K I R R M A N N – T h e I E C 6 1 8 5 0 sta n d a rd h a s b e c o m e th e b a c k b o n e o f su b sta tio n a u to m a tio n , a llo win g fo r th e rst tim e in te ro p e ra tio n b e twe e n p ro te c tio n , m e a su re m e n t a n d c o n tro l d e vic e s fro m d iffe re n t m a n u fa c tu re rs o n th e sa m e E th e rn e t lo c a l a re a n e two rk , sta tio n o r p ro c e ss b u s. T h is n e two rk is d u p lic a te d in su b sta tio n s th a t re q u ire a ve ry h ig h a va ila b ility. I n te ro p e ra b ility re q u ire s th a t a ll d e vic e s u se th e sa m e re d u n - d a n c y c o n c e p t. I E C 6 1 8 5 0 n o w sp e c i e s a n e two rk re d u n d a n - c y th a t fu l lls th e re q u ire m e n ts o f su b sta tio n a u to m a tio n , fo r th e sta tio n b u s a s we ll a s fo r th e p ro c e ss b u s. I t is b a se d o n two c o m p le m e n ta ry p ro to c o ls d e n e d in th e I E C 6 2 4 3 9 -3 sta n d a rd : p a ra lle l re d u n d a n c y p ro to c o l ( P R P ) a n d h ig h -a va il- a b ility se a m le ss re d u n d a n c y ( H S R ) p ro to c o l. B o th a re a b le to o ve rc o m e th e fa ilu re o f a lin k o r switc h with ze ro switc h o ve r tim e , wh ile a llo win g c lo c k syn c h ro n iza tio n a c c o rd in g to I E E E 1 5 8 8 to o p e ra te re lia b ly. D e ve lo p e d b y A B B in c o lla b o ra tio n with o th e r c o m p a n ie s, b o th P R P a n d H S R will b e p a rt o f th e se c o n d e d itio n o f th e I E C 6 1 8 5 0 sta n d a rd . B um pless Ethernet redundancy for substations w ith IEC 61850 S eam less redundancy 5 8 A B B review special report physical Ethernet netw ork could carry both the station and the process bus traffic. For the station bus, the netw ork topology generally adopted in large substations is that each voltage level uses a ring of sw itches, w hich connect the m ain pro- tection, backup protection and control IED s ➔ 1 . In sm aller m edium -voltage substations, a cost-effective arrange- m ent uses IED s that include a sw itch ele- m ent, w hich can be chained into a ring topology, m aking the netw ork resilient to the loss of one link ➔ 2 . In large substations, the different voltage level rings are connected to the station level in a tree form ation, allow ing the sta- tion bus to exhibit a m ixed ring and tree topology. A lternatively, a ring of rings for- m ation can also be used. At the process bus level, IED s are typically sim ple m easurem ent and control devices connected to the protection and control all transm itted inform ation and provide zero-sw itchover tim e if links or sw itches fail, thus fulfilling all the difficult real-tim e requirem ents of substation autom ation. P R P (IEC 62439-3 C lause 4) specifies that each device is connected in parallel to tw o local area netw orks of sim ilar to- pology. H S R (IEC 62439-3 C lause 5) ap- plies the P R P principle to rings and to rings of rings to achieve cost-effective redundancy. To this effect, each device incorporates a sw itch elem ent that for- w ards fram es from port to port. I E C 6 1 8 5 0 n e tw o rk to p o lo g y IEC 61850 encom passes tw o busses based on sw itched Ethernet technology [4]: –The station bus [5] interconnects all bays and the station supervisory level; it m ainly carries control inform ation, such as m easurem ents, interlocking and select-before-operate. Typically the m anufacturing m essaging specifi- cation (M M S ) protocol is used to transfer data betw een station level and bay level intelligent electronic devices (IED s) w hile generic object oriented substation events (G O O S E) looks after bay IED to bay IED data transfer. –The process bus [6] interconnects the IED s w ithin a bay and m ainly carries m easurem ents, know n as sam pled values (S V), for protection. The S V are sam pled at a nom inal value of 4 kH z in 50 H z grids (4.8 kH z in 60 H z grids). IEC 61850 does not prescribe a topolo- gy, tree, star or ring. Indeed, the sam e T he IEC 61850 standard re- places the num erous busses and links in use today by a hi- erarchy of w ell specified sw itched Ethernet netw orks, nam ely the station bus betw een the bays and the process bus w ithin a bay. To achieve in- teroperability, IEC 61850 Edition 2 speci- fies in greater detail the underlying proto- cols of these busses. Tw o indispensable netw ork features for a real-tim e system are given particular attention: tim e syn- chronization and netw ork redundancy. Tim e synchronization is solved by the sim ple netw ork tim e protocol (S N TP ) [1], w ith stricter requirem ents taken care of by the IEEE standard 1588 [2]. R edun- dancy w as a m ajor hurdle, since the lack of a com m only accepted redundancy protocol prom pted m anufacturers to m arket incom patible proprietary solu- tions. IEC 61850 edition 2 now includes tw o redundancy protocols, w hich are defined in the IEC standard 62439-3 [3] and ap- plicable to substations of any size and topology for the station bus as w ell as for the process bus: parallel redundancy protocol (P R P ) and high-availability seam less redundancy (H S R ). In both protocols, each node has tw o identical Ethernet ports for one netw ork connec- tion. They rely on the duplication of 1 A n o n -re d u n d a n t s ta ti o n b u s station supervisory level operator w orkplace G P S m ain m ain m ain backup backup backup control control control bay 1 bay 2 bay N IED IED IED IED IED IED IED IED IED copper links … s ta ti o n b u s ( ri n g ) optical fibre links netw ork control centre gatew ay logger sw itch S sw itch 1 sw itch 2 sw itch N 2 A ri n g w i th s w i tc h i n g e n d n o d e s operator w orkplace sw itch elem ent station bus as ring IED IED netw ork control centre IED IED gatew ay printer gg IED 5 9 S e a m le s s re d u n d a n c y control sequence is issued. The process bus, w hich carries tim e-critical data from the m easuring units, requires a determ in- istic m ode of operation, w ith m axim um delays in the order of 4 m s. The recovery tim es com piled by IEC technical com m it- tee 57 (TC 57) w orking group 10 (W G 10) are sum m arized in ➔ 4 . R edundancy w ill be regularly checked at intervals of less than one m inute for the com plete netw ork. O nly one device, sta- tion operator or gatew ay to the netw ork com m unication center (N C C ) is needed to m onitor the netw ork. C onfiguration er- rors are reported to the station operator or the N C C gatew ay. H i g h ly a v a i la b le n e tw o rk to p o lo g y IEC 62439 [3] is applicable to all indus- trial Ethernet netw orks [7], since it con- siders only protocol-independent m eth- ods. It contem plates tw o basic m ethods to increase the availability of autom ation netw orks through redundancy: R edundancy in the netw ork. The netw ork offers redundant links and sw itches, but nodes are individually attached to the sw itches through non-redundant links. The gain in availability is sm all since only part of the netw ork is redundant. R edundancy is norm ally not active, and its insertion costs a recovery delay. A typical exam ple of such a m ethod is the rapid spanning tree protocol (R S TP IEEE 802.1D [8]). H ow ever, R S TP can only guarantee a recovery tim e of less than a second in a restricted topology. N evertheless, R S TP is a good choice for the station bus in non-redundant system s, such as that show n in ➔ 1 . units, w hich interface to the station bus ➔ 3 . A ring topology at this level also offers a cost-effective w iring solution. T i m i n g re q u i re m e n ts i n s u b s ta ti o n n e tw o rk s The tim ing requirem ents for the station and process buses are distinct; they dic- tate how redundancy is used. The tim e during w hich the substation tol- erates an outage of the autom ation sys- tem is called the “grace”tim e, and the netw ork recovery tim e m ust be low er than the grace tim e. A s w ell as applying in cases of failure, the recovery tim e also applies to the reinsertion of repaired com ponents. W hen the station bus carries only com - m and inform ation, delays of som e 100 m s are tolerated. H ow ever, a delay of only 4 m s is tolerated w hen interlocking, trip and reverse blocking signals are carried, although it is unlikely that a failure w ill take place exactly w hen an (infrequent) 3 A p ro c e s s b u s to p o lo g y U /I sensors U /I sensors I sensors I sensors actor I sensors I sensors sw itch control sw itch control IA 1 IA L IC L IA 2 IB 1 IB 2 IC 1 IC 2 U C S U C L U A L U A S 9-2 traffic 8-1 traffic P I: P rocess interface P M C : P rotection, m easurem ent, control P M C 1 P M C 2 P I P I P I P I P I P I P I P I P I P I P I 5 R e d u n d a n c y i n th e n o d e s sw itched local area netw ork (ring) LA N _A sw itch sw itch sw itch sw itch sw itch sw itch sw itched local area netw ork (tree) LA N _B D A N P D A N P D A N P D A N P D A N P S A N A 1 S A N A 2 S A N R 1 S A N B 1 S A N B 2 S A N R 2 R edB ox 4 R e c o v e ry ti m e s c o m p i le d b y th e I E C T C 5 7 WG 1 0 C o m m u n i c a ti n g C o m m u n i c a ti n g R e c o v e ry p a rtn e rs p a rtn e rs T i m e S C A D A to IED client-server station bus 100 m s IED to IED interlocking station bus 4 m s IED to IED reverse blocking station bus 4 m s bus bar protection station bus 0 m s sam pled values process bus 0 m s In a redundant netw ork, the m ost im portant param - eter is the recovery tim e needed to restore error-free operation after a failure. B oth P R P and H S R offer zero recovery tim e. 6 0 A B B review special report ring and every node forw ards the fram es it receives from one port to the other. W hen the originating node receives a fram e it sent itself, it discards it to avoid loops; therefore, no special ring protocol is needed. To detect duplicates, the Ethernet fram es include a sequence num ber increm ented by the source for each sent fram e. C on- trary to P R P, the sequence num ber is not inserted after the payload, but in the header so the sw itch elem ent can recog- nize the duplicates before they are re- ceived entirely. Therefore, cut-through operation w ith less than 5 µs per node is possible. W ith respect to a single ring, the bus traffic is roughly doubled, but the aver- age propagation tim e is reduced, allow - ing the ring to support a sim ilar num ber of devices. Individually attached nodes, such as laptops and printers are at- tached through a “redundancy box”that acts as a ring elem ent. A pair of redundancy boxes can be used to attach a seam less ring to a duplicated P R P netw ork. In this case, each red box sends the fram es in one direction only. This overcom es the basic lim itation of a ring, and enables the construction of a hierarchical or peer netw ork ➔ 8 . P re c i s i o n c lo c k s y n c h ro n i z a ti o n The P R P /H S R schem e presents a chal- lenge for tim e synchronization as defined in IEEE 1588 because the delays over the tw o redundant netw orks are differ- ent. H ere, som e restriction to IEEE 1588 actually enabled the robustness and pre- cision of the clock system to be in- creased. nicate only w ith D A N P s and S A N s at- tached to the sam e netw ork), or are at- tached through w hat is know n as a red box, a device that behaves like a D A N P ➔ 6 . The nodes detect the duplicates w ith a sequence num ber inserted in the fram es after the payload. This allow s full trans- parency of P R P (D A N P ) and non-P R P (S A N P ) nodes. The com plete P R P proto- col can be executed in softw are. N ode failures are not covered by P R P, but du- plicated nodes m ay be connected via a P R P netw ork. H S R H S R applies the P R P principle of parallel operation to a single ring, treating the tw o directions as tw o virtual LA N s. This allow s a significant reduction in hardw are costs because no sw itches are used and only one link is added. H ow ever, all nodes of the ring m ust be sw itching nodes, ie, they have tw o ports and inte- grate a sw itch elem ent, preferably im ple- m ented in hardw are, as show n in ➔ 7 . For each fram e sent, a node sends tw o fram es –one over each port. B oth fram es circulate in opposite directions over the R edundancy in the nodes. A node is attached to tw o different redundant netw orks of arbitrary topology by tw o ports ➔ 5 . Each node independently chooses the netw ork to use. This schem e supports any netw ork topology; the redundant netw orks can even exhibit a different structure. The cost of im plem enting this redundancy m ethod is about tw ice that of the redundancy m ethod discussed in the previous bullet, but the gain in availability is large. The only non- redundant parts are the nodes them selves. W ith regard to P R P, IEC 62439-3 C lause 4 specifies redundancy in devices in w hich the nodes use the tw o netw orks sim ultaneously. This offers zero recovery tim e, m aking P R P suited for all difficult real-tim e applications. IEC 62439-3 C lause 5 defines another redundancy-in-the-nodes solution w ith H S R , in w hich a sw itch elem ent is inte- grated in each device. The operating m ode is the sam e as for P R P. P R P o p e ra ti n g p ri n c i p le Each P R P node, called a doubly attached node w ith P R P (D A N P ) is attached to tw o independent local area netw orks (LA N s) operated in parallel. The netw orks are com pletely separated to ensure fail- ure independence and can have different topologies. B oth netw orks operate in parallel, thus providing zero-tim e recov- ery and the continuous checking of re- dundancy to avoid lurking failures ➔ 5 . N on-P R P N odes, called singly attached nodes (S A N ) are either attached to one netw ork only (and can therefore com m u- 6 A d u p li c a te d s ta ti o n b u s w i th p a ra lle l re d u n d a n c y p ro to c o l ( P R P ) D A N P D A N P D A N P D A N P D A N P S A N R ed B ox D A N P S A N S A N sw itch sw itch sw itch sw itch sw itch sw itch sw itch D A N P D A N P sw itch … 7 A h i g h -a v a i la b i li ty s e a m le s s re d u n d a n c y ( H S R ) p ro to c o l ri n g node node node node node node node singly attached nodes source destinations “C ”-fram e “A ”-fram e (H S R ) “B ”-fram e (H S R ) “D ”-fram e interlink R ed B ox destinations sw itch B A P R P offers easy integration of non- redundant devices, w hile H S R offers cost-effective ring topologies. 6 1 S e a m le s s re d u n d a n c y H u b e rt K i rrm a n n A B B S w itzerland C orporate R esearch B aden, S w itzerland hubert.kirrm ann@ ch.abb.com R e fe re n c e s [1] Internet R FC 2030 sim ple netw ork tim e protocol (S N TP ) Version 4 (1996) from IP v4, IP v6 and O S I. [2] The Institute of Electrical and Electronic Engineers. IEEE S td 1588: S tandard for a precision clock synchronization protocol for netw orked m easurem ent and control system s. [3] International Electrotechnical C om m ission, G eneva IEC 62439 (2010). H ighly available autom ation netw ork suites. [4] The Institute of Electrical and Electronic Engineers, (2005). C S M A /C D access m ethod and physical layer specifications. IEEE S td 802.3. [5] International Electrotechnical C om m ission, G eneva. IEC 61850-8: C om m unication netw orks and system s in substations. P art 8-1: S pecific com m unication service m apping (S C S M ) –M appings to M M S (IS O 9506-1 and IS O 9506-2) and to IS O /IEC 8802-3. [6] International Electrotechnical C om m ission, G eneva. IEC 61850-9-2: C om m unication netw orks and system s in substations. P art 9-2: S pecific com m unication service m apping (S C S M ) –S am pled values over IS O /IEC 8802-3. [7] International Electrotechnical C om m ission, G eneva (2006). IEC 61784-2, A dditional profiles for IS O /IEC 8802.3 based com m unication netw orks in real-tim e applications. [8] The Institute of Electrical and Electronic Engineers, (2004). A N S I/IEEE S td 801.2D , M edia access control (M A C ) B ridges. F u th e r re a d i n g – International Electrotechnical C om m ission, G eneva TC 57 W G 10 IEC 6185090-4. N etw ork engineering guidelines (in preparation). – D zung, D ., and K irrm ann, H . (2006). S electing a standard redundancy m ethod for highly available industrial netw orks. W FS C 2006 Torino. – M eier, S . (2007, January 25). ZH W InES –P R P : D oppelt gem oppelt hält besser. Electrosuisse, ITG Fachtagung, Zurich-K loten. The bay control units (R EC 670) are con- nected by tw o com pletely separated net- w ork rings. The entire system is synchro- nized using S N TP sent in parallel to both netw orks using tw o independent G P S receivers w ith integrated S N TP tim e servers. The com m unication system is supervised using S N M P and the failure of the redundant connection of any device is im m ediately reported to the system . I d e a l re d u n d a n c y s c h e m e s P R P and H S R m ake an im portant contri- bution in achieving interoperability –w ith respect to redundant com m unication – betw een protection, m easurem ent and control devices from different m anufac- turers ➔ 1 0 . Their success relies on the ability of A B B to team up w ith com peti- tors and suppliers to ensure device in- teroperability in the custom er’s interest. 9 A s y s te m o v e rv i e w u s i n g P R P R EC 670 R EC 670 .... R EC 670 R EC 670 R edundant Ethernet B us R EC 670 R EC 670 M icroS C A D A 1 G P S S w itch S w itch S w itch S w itch S w itch S w itch M icroS C A D A 2 G P S 8 H S R ri n g o f ri n g s quadboxes upper ring (station level) voltage level 1 voltage level 2 voltage level 3 sub-ring operator w orkplace G P S clock m aintenance laptop m 1 0 P R P a n d H S R fe a tu re s P R P and H S R provide ideal redundancy schem es for IEC 61850-based substations in that they: – Fulfill all requirem ents of substation autom ation according to IEC 61850 – C an be used in a variety of topolgies, eg, rings, trees. – A re transparent to the application – Tolerate any single netw ork com ponent failure – A chieve zero recovery tim e, m aking it suitable for the m ost tim e-critical processes – D o not rely on higher layer protocols – A re com patible w ith R S TP – P R P allow s nodes not equipped for redun- dancy to operate on the sam e netw ork – U se off-the shelf netw ork com ponents (tools, controllers, sw itches and links) – S upport precision tim e synchronization according to IEEE 1588 – H ave been proven in the field in high-voltage substations F i e ld e x p e ri e n c e The first substation autom ation (S A ) sys- tem for a high-voltage substation w ith control devices operating under P R P is now ready for installation. The tests have proven that the technology is m ature for substation autom ation devices and it perform s as expected. O ne of the m ajor requirem ents for this project w as to have fully redundant com m unication dow n to the bay level IED s to rem ove any single point of failure in the substation control. This called for full duplication, w ith re- dundant station com puters (M icroS C A - D A 1 and M icroS C A D A 2 in hot stand-by configuration for control and m onitoring at the substation level as w ell as redun- dant gatew ay functionality for telecontrol. For bay level control, A B B ’s latest control device for high-voltage applications, the R EC 670, is used ➔ 9 . printer 6 2 A B B review special report T he developm ent of pow erful tools and efficient processes sim plifies the im plem entation of IEC 61850 across the port- folio of products, applications and sys- tem s. Full com pliance to the standard is verified by an in-house system verifica- tion center, the w orld’s first vendor- ow ned test laboratory to earn qualifica- tion by the U C A International U sers G roup. The state-of-the-art product portfolio along w ith proven system integration ca- pabilities enables A B B to realize the standard’s full potential in substation au- tom ation system s. This is equally en- sured in system s w ith centralized and decentralized architectures, G O O S E- based and distributed functions as w ell as m ulti-vendor integration and latest enable ef cient pow er system m anage- m ent and integrate substations that are reliably supplying energy from conven- tional and renew able resources to m illions of people or are pow ering industrial pro- ductivity, into the sm art grid. This m ap show s a selection of IEC 61850 im plem entations around the w orld w ith A B B participation. IEC 61850 – a success story around the w orld P E T R A R E I N H A R D T – S in c e th e p u b lic a - tio n o f th e I E C 6 1 8 5 0 sta n d a rd a n d th e c o m m issio n in g o f th e wo rld ’ s rst m u lti-ve n d o r p ro je c t in L a u fe n b u rg in 2 0 0 4 , A B B h a s su p p o rte d n u m e ro u s c u sto m e rs in a c c o m p lish in g th e p a ra d ig m c h a n g e a sso c ia te d with in tro d u c in g I E C 6 1 8 5 0 su b sta tio n a u to m a tio n syste m s. M e a n wh ile , m o re th a n a th o u sa n d syste m s a n d a va st n u m b e r o f p ro d u c ts h a ve b e e n d e liv- e re d to a ro u n d 7 0 c o u n trie s re su ltin g in c o m p re h e n sive e x p e rie n c e with n e w in sta lla tio n s, re tro t a n d m ig ra tio n p ro je c ts. S ubstation autom ation system s pave the w ay to a sm arter grid technologies such as sensors integrated via the process bus. The continuous com m itm ent to the global IEC 61850 standard from the m id nineties and into the future w ith expert engage- m ent in new editions as w ell as extensions into other dom ains such as pow er gener- ation, com m unication betw een substa- tions and to netw ork control centers al- low s AB B to support custom ers w anting to benefi t from these developm ents. O ffering its com prehensive dom ain know l- edge both of the pow er value chain and industrial processes, A B B provides utility and industry custom ers w ith S A system s leveraging both current and future per- spectives and benefi ts of the standard. Facilitating enterprise-w ide data integra- tion, the IEC 61850 autom ation system s 1 5 3 4 6 6 3 A B B R e v i e w S p e c i a l R e p o rt I E C 6 1 8 5 0 A u g u s t 2 0 1 0 E d i to ri a l C o u n c i l P e te r Te rw i e s c h C hief Technology O fficer G roup R &D and Technology C la e s R y to ft H ead of Technology P ow er S ystem s division claes.rytoft@ ch.abb.com H u g o E . M e i e r H ead of G lobal P roduct M anagem ent S ubstation A utom ation hugo.e.m eier@ ch.abb.com H a rm e e t B a w a H ead of C om m unications P ow er S ystem s and P ow er P roducts harm eet.baw a@ ch.abb.com P e tra R e i n h a rd t C om m unications M anager B usiness U nit S ubstations petra.reinhardt@ ch.abb.com A n d re a s M o g le s tu e C hief Editor, ABB Review andreas.m oglestue@ ch.abb.com P u b li s h e r ABB Review is published by A B B G roup R &D and Technology. A B B A sea B row n B overi Ltd. 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IS S N : 1013-3119 w w w. a b b . c o m /a b b re v i e w N ew installation R etrofit/m igration 7 8 1 0 1 1 1 4 1 5 1 2 1 3 9 2 ➔ 1 Teck C om inco’s W aneta 230/63 kV S /S , C anada ➔ 2 EG L’s Laufenburg 380 kV S ubstation, S w itzerland ➔ 3 ED P D istribuiçao Energia’s six H V/M V stations, P ortugal ➔ 4 S enelec’s H ann 90/30 kV S /S , S enegal ➔ 5 EN ELVEN ’s and EN ELC O ’s S oler & M édanos S /S s, Venezuela ➔ 6 Eletrosul’s three 230/69 kV S /S s, B razil ➔ 7 EW A’s Financial H arbour, S itra & B uquw w ah S /S s, B ahrain ➔ 8 D EW A S A fram e contracts, D ubai ➔ 9 Transco’s and A D W EA’s new 400 - 11 kV G IS S /S s, A bu D habi ➔ 1 0 Federal G rid C om pany’s O chakovo 500/220/110 kV S /S , R ussia ➔ 1 1 N TC ’s six new 161/22.8 kV S /S s, Taiw an ➔ 1 2 S ix new H V substations for P G C IL, India ➔ 1 3 S A for P T P LN ’s five retrofit 150 kV S /S s, Indonesia ➔ 1 4 N G C P ’s P itogo S /S and M eralco’s A m adeo S /S , P hilippines ➔ 1 5 R io Tinto/H am ersley Iron’s 220 kV Juna D ow ns S /S , A ustralia The IEC 61850 open communication standard provides a common framework for substation automation and facilitates interoperability across devices and systems. ABB’s IEC 61850 compliant systems enable real-time control and monitoring and help maximize availability, efficiency, reliability and safety. They enable flexibility for multi-vendor integration and extension, in addition to supporting enterprise-wide data integration for efficient power system management. With an unparalleled installed base and a proven track record of technology and innovation, ABB is a substation partner you can depend on. www.abb.com Power under control? ABB Switzerland Ltd Tel. +41 58 585 77 44 Fax. +41 58 585 55 77 Email :
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