Power Transmission and DistributionControlled Switching of High-Voltage Circuit-Breakers PSD02 each pole receives an individual switching command from the control unit. Generally.Controlled switching When switching capacitive and inductive loads. Resulting destruction may occur in the capacitors. Controlled switching allows for a individual optimum switching instant to be set for each pole. For circuit-breakers with three independent drives. reduces the load on the capacitor bank and improves the quality of the voltage of the network. The transients are thereby reduced to a minimum. complex mechanical auxiliary equipment. unfavorable switching conditions normally occur in at least one phase. These stresses can be minimized by the introduction of controlled switching. switching transients occur. The intensity of the transients during switching operations depends on the phase position at the point of switching. The transients vary accordingly. Due to the arbitrary switching instant and the shifts of the three phases with respect to each other. in the individual phases. however. A circuit-breaker without this unit operates all three phases at approximately the same instant. resulting in electrodynamic and dielectric stresses on system. such as closing resistors. random phase positions tend to occur. which can be provided by the PSD02 control unit from Siemens. Longer service life of equipment by reducing switching over-voltages and inrush currents. Controlled switching – Less wear and tear on the equipment Non-controlled closing of a capacitor bank at a voltage peak can result in high inrush currents and over-voltages. Closing the contact at the optimal point in time. Possible substitution of costly. which greatly exceed the nominal system values. the capacitors are heavily loaded both mechanically and dielectrically which can lead to premature ageing. 200 200 % 100 % 100 0 0 U 1 U 2 0 20 40 t 60 80 ms 0 20 40 t 60 80 ms Switching a capacitive load 1 Closing time not optimised 2 Closing time optimised 2 . This unit offers the following advantages: Increased system reliability as a result of reduced voltage fluctuations and lower harmonic stress. Consequently. In the cases described thus far. A re-ignition across the open breaker contacts may result. The induction generated saturates the iron core and induces an inrush current which results in a high load on the transformer or reactor. Controlled switching offers an economical alternative. non-controlled making or breaking can lead to increased stress on the equipment. 1000 % 1000 % 500 500 0 0 U U 1 0 20 40 t 2 60 80 ms 0 20 40 t 60 80 ms Switching a transformer 1 Closing time not optimised 2 Closing time optimised 3 . thus protecting the equipment. if the isolating distance at this instant is not sufficient to withstand the dielectric load. may result in a very high direct current component. Controlled switching also offers a remedy in this case. Controlled switching at the voltage crest will also prevent switching transients from occurring. Closing resistors and reactors that were previously used to reduce these stresses may no longer be required.Front view of PSD device Reactors and transformers Non-controlled energizing of a reactor or a transformer close to the voltage zero crossing. Over-voltages are inevitable. This process is known as current chopping and leads to steeply rising over-voltage. Non-controlled de-energizing of inductive loads such as shunt reactors or transformers means that the circuit-breaker can interrupt smaller currents before the natural zero crossing. Optimization of the open-close operational instant prevents re-ignitions and the over-voltages are minimized. An option is available for inputting individual parameter set points for frequency. including an input signal that has not been received. Climatic and mechanical tests in accordance with IEC 60068 and IEC 60255 demonstrate unlimited functionality even under disruptive environmental influences. Back view with straight through current transformers 4 .The functions and features of the PSD02 control unit Main features at a glance One device for all switching Unrestricted parameter-definable software Standard CLOSE. In the case of hydraulically driven breakers. Voltage and current time curves. alarms. and climatic tests. or not reached. Easy graphical evaluations of all the recorded signals of the switching with the help of windows – compatible software. In such cases the control of the switching instant does not occur. The EMC test in accordance with IEC 61000 and IEC 60255 and the test for low noise emission in accordance with EN 55011 have been passed successfully. hardware. including previously installed circuit-breakers with minimum alteration of the opening and closing time and retain a sufficiently steep pre-arcing characteristic curve. Experience Many years of experience in the use and development of control units have gone into the development of the PSD02. Two separately configured parameter settings in the control unit make it possible to control a circuitbreaker by carrying out two different switching tasks. In history. To compensate for possible deviations in the opening and closing times of a circuit-breaker. if a switching operation is not successfully performed. Monitoring of sensors. When opening small inductive currents. the data is acquired cyclically and is event-controlled and stored in a nonvolatile memory. inputs from the control room and outputs from the circuit-breaker) including reference contact signals. Individual detection of the positions of the circuit-breaker pole with a monitoring function by means of 4 auxiliary switch inputs. Different compensation characteristics are selectable. The PSD02 control unit is suitable for all Siemens high-voltage circuit-breakers. the drive energy (hydraulic pressure) is also compensated. adaptive control Two switching procedures can be specified at the same time Linear and vectorial compensation Secure current measurement with “Ring-type transducers” Software operation protected by user hierarchy Evaluation using graphic user interface RS 485 and RS 232 communication interfaces Switching history can be transferred Cyclic history. the PSD02 control unit offers two functions to perform making and breaking at the optimal instant for each pole: The PSD02 also compensates on the dependence of the operating times on the ambient temperature and the control voltage. measurement values Functions The following data can be acquired from the unit: The PSD02 control unit optimizes the phase relative to the current or voltage of the switching operation of the circuit-breaker by evaluating these figures. voltages and temperatures. Controlled switching takes the current opening and closing times of the circuit-breaker into account. and the voltage supplies. Closing occurs at an optimal phase position relative to the voltage. Alarm signals can then be generated when a set point is exceeded. A mode input automatically selects between the two tasks during operation. This control unit has been subjected to comprehensive electrical.g. Opening commands that are generated by the protection system in case of short circuit are passed directly onto the circuit-breaker. All input and output signals. The functions and features of the PSD02 control unit The PSD02 control unit offers a wide-range of functionalities. or if no zero crossing of the reference voltage has been detected. Oscillograms are stored in a buffer memory and available even after supply interruptions. Output of error messages (alarms). mechanical.and OPEN-trigger circuits Parameter-definable. Process curves of the switching commands (e. The PSD02 has a wide range of monitoring and evaluation functions to track the success of the controlled switching operations and its internal functions. Integration into the substation The PSD02 control unit is integrated into the substation control system so that the switching commands for operation can be processed. The phase position is selected based on the actual switching duty so that transients can be avoided. Data-acquisition of the most important data from approximately 400 events and switching operations by means of the history function. the voltage cycle of the contact separation is such that the contact clearance during interruption is sufficient to prevent re-ignition. The last four switching operations. e.g. It can select and set the opening and closing instant for each switching pole individually. Commands from the protection system are passed directly onto the circuit-breaker. protected against polarity reversal.10 Arms internal supply internal supply internal supply same reference dimensions. DB9/DCE. Rin=240 kΩ. insulated same reference dimensions.300 Vdc.-STF...360 Vdc Power consumption: 15 W Mains buffering.20 mA. 57000 bps. 20 A.300 Vdc..300 Vdc.. insulated same reference dimensions. sampling rate: 10 kHz.. Rin=20 kΩ 45.. 24 V 0.300 Vdc 0. insulated f0=1 kHz..20 mA. insulated protected against polarity reversal.5. capacitor-buffered Connection technology: COMBICOM PHOENIX contact system – recommended connection cross-section: 2. 5 ms..300 Vdc.. AWG 24-12 1 x 6-pole. SUB-D9 Resolution. monitoring of supply interruption Analog inputs: 1x temperature 3x oil pressure 3x reserve 1x control voltage 1x MAKE-trip voltage 1x OPEN-trip voltage 4x voltage transformer 3x current transformer Digital inputs: 1x MODE 1x AUX-make-contact pole A 1x AUX-make-contact pole B 1x AUX-make-contact pole C 1x AUX-open-contact poles ABC 1x CLOSE-command 1x OPEN-command 3x Reference contact Outputs: 3x power outputs CLOSE 3x power outputs OPEN 8x relay contact 8x LED display Communication interfaces: DTE/DCE communication 1x EIA RS-232.. 115000 bps. Imax=100 A (5 ms) (268. 20 MHz. 0.. Rin=20 kΩ 45. insulated protected against polarity reversal. sensor inputs 1 s.. insulated protected against polarity reversal... 10 Bit Switching precision: 0. Rin=20 kΩ 45.20 mA. insulated f0=1 kHz.5 mm².300 Vdc. 100 A. 24 V 4. DB9/DCE. switching capacity 2000 VA constant current 8 A.5 mm (3U) Width: 237 mm (9.....C167CR. no-load and over-load..300 Vdc.. insulated protected against polarity reversal. 512K SRAM... 250 ms. Rin=20 kΩ 45. 2. insulated protected against polarity reversal. insulated protected against polarity reversal.5 s or 25 A.. Rin=20 kΩ 45..300 Vdc 0. 3 x 12-pole. non-condensing Accessories: 1x serial modem cable 1x software 1x manual 24.5”) Depth: 288 mm Weight: 4 kg Ambient conditions: -40 °C to +70 °C Free air convection. Imax=30 A (90°C). 24 V protected against polarity reversal. RTC. serial modem. 24 V 4. insulated internal supply 4.. short-circuits.. 200 ms (90°C)...300 Vdc 0. 10 Bit...5 A 45.1 ms System: 16-Bit microcontroller . operating range 300 Vdc / 0. SUB-D9 1x EIA RS-485.2-2.Technical Data Voltage supply: Voltage: 40.. Rin=88 mΩ.20 mA..5/.212 Vac 1. Rin=20 kΩ 45. Rin=20 kΩ 4.300 Vdc..5 mm² Type MSTB 2..5 mm with securing bracket) 5 . 3 x 16-pole Housing: 42HP/3U HF module support with perforated cover plate Protection category: IP2 Height: 132.. 512K FLASH. short-circuit interrupt time <10 µs 1 two-way contact. insulated.300 Vdc. Subject to change without prior notice.siemens. 72.hv-circuit-breaker.com www. The required features should therefore be specified in each individual case at the time of closing the contract.5 kV to 420 kV Live-tank and dead-tank high-voltage circuit-breakers technology High-voltage circuit-breakers: Type 3AT2/3.com/ptd The information in this document contains general descriptions of the technical options available. which do not always have to be present in individual cases. 245 kV to 550 kV Hydraulic operating mechanisms for high-voltage circuit-breakers SF6 in power engineering – acting responsibly Further copies of this brochure For further information Please fax this page to the following number: Fax +49 30/386-25867 or send us an e-mail: circuit-breaker@siemens. Order No. E50001-U113-A145-V2-7600 Printed in Germany Dispo 30000 By.Name Position Company Street Postcode/City/Country Phone/Fax Please send me more information on the following topics: High-voltage circuit-breakers for outdoor installation High-voltage circuit-breakers: Type 3AP1/2.com Siemens AG Power Transmission and Distribution High Voltage Division Nonnendammallee 104 13629 Berlin Germany www.5 . PA 1105 1.