MEPSA conferenceSydney, February 2009 Frank Cerra The new IEC 60034‐2‐1 test method standard 1 IEC60034‐2‐1 • Establishes Harmonized methods for determining efficiencies of rotating electrical machines and also the methods of obtaining specific losses • Covers DC, Synchronous and Asynchronous electrical machines • Published in September 2007 2 Background • Inconsistency in motor efficiency determination existed from the treatment and measurement of the stray load loss component of motor losses. – IEC 34‐2(1972)&amdt2(1996): P LL = 0.5% . P in – IEEE 112 method B: P LL from measurement – JEC 37(1979): assumes P LL = 0, but JIS C 4212 similar to IEEE112B – IEC61972: similar to IEEE112B – AS 1359.102.3 (similar to IEEE112B) and AS 1359.102.1 (similar to IEC34‐2). 3 • IEC TC2 WG28 – Was tasked to modify the IEC method to include method of measurement of stray load losses, and improve motor efficiency accuracy – Focus on harmonized test methods that would be consistent with the majority of the world i.e. IEC, IEEE – Introduced IEC60034‐2‐1 that includes as the “preferred method” or the “method with least uncertainty” for determining strays that method as described in 61972 i.e. equivalent to IEEE112‐B Background 4 IEC60034‐2‐1 Table 2 – Induction Machines 5 Uncertainty • IEC60034‐2‐1 assigns uncertainty to test methods 6 Uncertainty Efficiency determination LOW From tests MEDIUM Based on limited approximations HIGH Based on assumptions Summation of Losses Treatment 7 Method of least uncertainty is where Stray Load Losses are based on direct measurement Motor losses • Motor losses consists of five components: – Stator copper losses: I 2 R s – Iron losses: P FE – Rotor copper losses: I 2 R r – Friction & windage losses P f – Stray load losses: P LL • P FE and P f from no‐load test • I 2 R s and I 2 R r from R, s and P in – load test • P LL – indirectly measured or from assigned value 8 P LL determined from residual loss • Stray load losses determined from measurement • Requires accurate measurement of torque and speed – Torque measurement was historically difficult, but is now possible • Uncertainty = LOW • Equiv. to IEEE112B 9 P LL from assigned value • Where in IEC60034‐ 2(1996) a fixed 0.5% was used, In IEC60034‐2‐1 the “assigned value” ranges from 2.5% for small motors to 0.5% for large motors • Uncertainty with this method is “medium to high” because of assigned value 10 P LL from EH‐Star method • With this method, the losses are measured indirectly, with the Stray Load Losses calculated by mathematical means. • Alleviates the need for accurate torque measurement, but loading machine is still required to measure other losses • Uncertainty with this method is “medium” 11 Round Robin Tests • To address variation in energy efficiency reported by different motor manufacturers and testing laboratories • Standardized test procedure – summation of losses with load test – based on IEC60034‐2‐1 – Important for global harmonization of efficiency test methods and classes 12 Round Robin • To collect experience with the test methods in IEC60034‐2‐1, and assess the uncertainty associated with different test methods. • To obtain test data to assess measurement deviations between laboratories • To improve and optimize the test procedures • To provide experience and insight into the issue of tolerances (a basis for reviewing tolerance limits in IEC60034‐1) 13 Round Robin ‐ status • 21 laboratories in 9 countries agreed to participate. • Project is being managed by Robert Bartheld (TC2 WG28) • Part 1 (Same Motor): – The participating labs completed 13 sets of data, which is 50% of the expected results. • Part 2 (Same design): – The participating labs completed 9 sets of data, which is 34% of the expected results. • Part 3 (Same motor, different labs) – The plan is to test 6 motors from 3 to 5 labs depending upon rating. Only 5 sets of data have been completed covering 3 of the motors. • Results are expected 2009 14 Relationship between standards • IEC 60034‐2‐1: Testing standard, published: 10 September 2007 • Round‐Robin test for motors • IEC 60034‐30 Ed. 1: Efficiency Classes, published on 22 October 2008 • IEC 60034‐31: Guide for the selection and application of energy‐efficient motors including variable‐speed applications, IEC/WG 31 has published a first draft. Comments until 5 September 2009. 15 Thankyou 16