IEEE 436-1991 en Guide for Making Corona (Partial Discharge) Measurements on Electronics Transformers《电子变压器电晕(部分放电)测量指南》.pdf

1、IEEE Std 436-1991 (R2007)(Revision of IEEE Std 436-1977)IEEE Guide for Making Corona (Partial Discharge) Measurements on ElectronicsTransformersSponsorElectronics Transformer Technical Committeeof the IEEE Power Engineering SocietyReaffirmed 5 December 2007Approved 11 February 1991IEEE-SA Standards

2、BoardAbstract: A uniform procedure for making corona (partial discharge) measurements by electrical means onelectronic tranformers is presented. Methods of applying voltage stress, the use of a sine-wave voltage tosimulated dc and ac combinations, the types and limitations of voltage stresses encoun

3、tered, and the accept-able limits of discharge pulse energy are included. Recommended test conditions and the need for negotiationof special tests are discussed. Test apparatus and calibration are described. The aim is to establish a commonground of understanding between transformer and systems desi

4、gn engineers and transformer manufacturersin the development of service and performance requirements.Keywords: corona, partial discharge, insulation breakdown, transformer insulationThe Institute of Electrical and Electronics Engineers, Inc.345 East 47th Street, New York, NY 10017-2394, USACopyright

5、 1991 by the Institute of Electrical and Electronics Engineers, Inc.All rights reserved. Published 1991 Printed in the United States of America.ISBN 1-55937-126-9No part of this publication may be reproduced in any form,in an electronic retrieval system or otherwise,without the prior written permiss

6、ion of the publisher.IEEE Standards documents are developed within the Technical Committees of the IEEE Societies and the Standards Coordinating Committees of the IEEE Standards Board. Members of the committees serve voluntarily and without compensation. They are not necessar- ily members of the Ins

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15、articles, materials, or processes. Such adop- tion does not assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the standards documents. (This Foreword is not a part of IEEE Std 436-1991, IEEE Guide for Making Corona (Partial Discharge) Measuremen

16、ts on Electronics Transformers.) This guide was written to provide electronics transformer engineers with a standard method for detecting and measuring corona (partial discharge) in electronics transformers. Since there is no simple definition or unit for corona, it is felt that a guide of this natu

17、re will be useful in establish- ing a common ground of understanding between transformer and systems design engineers and transformer manufacturers in the development of service and performance requirements. This publication was prepared by the Insulation Systems Subcommittee of the Electronics Tran

18、sformers Technical Committee of the IEEE Power Electronics Society. The Subcommittee membership was as follows: R, A. Frantz, Chair J. S. Andresen C. J. Elliott H. Fickenscher P. K. Goethe R. R. Grant H. E. Lee D. N. Ratliff R. L. Sell B. D. Thackwray R. M. Wozniak When the Electronics Transformer T

19、echnical Committee approved this guide, the membership was as follows: E Fickenscher, Chair E. D. Belanger C. J. Elliott R. A. Frantz P. K. Goethe J. Silgailis J. Tardy B. D. Thackwray R. M. Wozniak H. E. Lee W. E. Lucan D. N. Ratliff R. L. Sell The following persons were on the balloting committee

20、that approved this standard for submis- sion to the IEEE Standards Board: J. S. Andresen E. D. Belanger R. P. Carey E. J. Elliott H. Fickenscher R. A. Frantz P. K. Goethe R. R. Grant 0. Kiltie L. W. Kirkwood H. E. Lee R. Lee H. W. Lord W. Lucarz D. Ratliff R. L. Sell J. Silgailis J. Tardy B. D. Thac

21、kwray H. I. Tillinger R. G. Wolpert R. M. Wozniak The final conditions for approval of this guide were met on February 11, 1991. This guide was conditionally approved by the IEEE Standards Board on September 28, 1990 with the following membership: Marc0 W. Migliaro, Chair Dennis Bodson Paul L. Borri

22、ll Fletcher J. Buckley Allen L. Clapp Stephen R. Dillon Donald C. Fleckenstein Jay Forstefl Thomas L. Hannan James M. Daly, Vice Chair Andrew G. Salem, Secretary Kenneth D. Hendrix John W. Horch Joseph L. Koepfingerl Irving Kolodny Michael A. Lawler Donald J. Loughry John E. May, Jr. Lawrence V. McC

23、all L. Bruce McClung Donald T. Michael* Stig Nilsson Roy T. Oishi Gary S. Robinson Terrance R. Whittemore Donald W. Zipse *Member Emeritus caltata SECTION PAGE 1 . Scope . 6 2 . Purpose 6 3 . References 6 4 . Definitions 6 5 . Test Conditions 7 5.1 Application of This Guide . 7 5.2 Conditions for Ac

24、ceptable Corona Tests . 7 5.2.1 5.2.2 Effects of Voids in Solid Insulation . 7 5.2.3 5.2.4 Circuit Response 7 5.3 Signal-to-Noise Ratio 8 5.4 Discrimination Device Sensitivity 8 Frequencies at Which Corona Measurements May Be Performed . 7 Corona Discharge Pulse Rise Time 7 6 . Apparatus . 8 6.1 Tes

25、t-Voltage Supply 8 6.1.1 Self-Excitation 8 6.2 Coupling Capacitor . 8 6.3 Coupling Impedance . 8 6.4 Corona Detector . 8 6.4.1 Amplifier . 10 6.4.2 Signal Readout Instrument(s1 10 6.5 Calibration Pulse Generator . 11 6.6 Calibration Coupling Capacitor 11 6.7 Control Metering 11 7 . Calibration . 11

26、7.1 Deflection Sensitivity . 11 7.2 When Calibration Is Performed . 11 7.3 Calibration Technique . 11 7.4 Calculating Detection Sensitivity . 12 8 . Test Method 12 8.1 Group I 12 8.2 Group I1 . 12 8.3 Group I11 12 9 . Test Requirements . 12 9.1 Ambient Conditions . 12 9.2 Calibration Sensitivity . 1

27、2 9.3 Test Voltage 13 9.3.1 DC Plus AC Test Voltage 13 9.4 Rate of Application 13 9.5 Duration of Tests 13 10 . Bibliography . 13 FIGURES PAGE Fig 1 Typical Circuit for Corona Measurement. Circuit 1 9 Fig 3 Circuit Modifications for Self-Excitation 10 Fig 4 Parallel-T RC Filter Network . 10 Fig 5 Pe

28、ak-to-Peak Voltmeter Circuit . 11 Fig 2 Typical Circuit for Corona Measurement, Circuit 2 9 APPENDIXES Appendix A. Preconditioning for Determination of CIV . 14 Appendix B . The Magnitude and Energy of Discharges . 15 Appendix C . Suggested Specification Requirements . 16 IEEE Guide for Making Coron

29、a (Partial Discharge) Measurements on Electronics Transformera This guide covers the detection of corona (partial discharge) and the measurement of its magnitude in electronics transformers. Test conditions, test apparatus, calibration, and test requirements are included. Corona (partial discharge)

30、is an ionization phenomenon that can cause deterioration in certain insulation systems. Its presence in electronic equipment can be harmful through its manifestation as circuit noise, spurious voltage or current pulses, or other undesirable effects that lead to circuit malfunctions. Transformers and

31、 inductors used in elec- tronic circuits at high voltages can be loca- tions where this harmful phenomenon origi- nates. Even in instances where discharges are not of concem in circuit performance, they may be of concem because of their adverse ef- fect on component life. It is, therefore, essen- ti

32、al that the insulation system be free of corona discharges at operating voltage stresses. The magnitude or intensity of these discharges is usually of such a low level that very sensitive electronic measuring apparatus and tech- niques are required to detect them. This guide presents a uniform proce

33、dure for making corona (partial discharge) measure- ments by electrical means on electronics transformers. Methods of applying voltage stress, the use of a sine-wave voltage to simu- late dc and ac combinations, the types and limitations of voltage stresses encountered, and the acceptable limits of

34、discharge pulse energy are included. Recommended test con- ditions and the need for negotiation of special tests are discussed. T)ris guide shall be used in conjunction with the following publications. ill ASTM D1868-1981 (R19901, Standard Method for Detection and Measurement of Partial Discharge (C

35、orona) Pulses in Evaluation of Insulation Systems. 21 IEEE Std 100-1988, IEEE Standard Dictionary of Electrical and Electronics TermsAth ed. (ANSI).2 3 MIL-T-27E, Military Specification Transformers and Inductors (Audio, Power, and High-Power Pulse), General Speci- fic: however, insistence on exact

36、condi- tions may be impractical. The fundamental conditions for acceptable corona tests are based on the assumptions and limitations that follow. 5.2.1 Frequencies at Which Corona Measurements May Be Performed. Corona discharges are a function of the peak-to-peak voltage, provided the voltage contai

37、ns no in- termediate peaks and is applied long enough for ionization to take place. Corona measure- ments may be performed at any frequency un- der 2000 Hz; they need not be made at the operating frequency. However, discharges are affected by the test frequency; as the frequency is increased, variat

38、ions occur in the response times of ions within the insulation to the rapidly varying externally applied electric field. The resulting nonuniform internal electrical stress leads to a decrease in the corona inception voltage. Care must therefore be taken in interpreting the results of tests performe

39、d at other than the operating frequency. 5.2.2 Effects of Voids in Solid Insulation. Corona discharges across voids in solid insu- lation transfer some of the voltage stress to the solid insulation, thus reducing the stress on the void. This removes the condition neces- sary for additional discharge

40、s until some of the charge dissipates or until the applied volt- age changes enough to reestablish the stress required for corona discharge. 6.2.2.1 Testing With DC Voltage. When the applied voltage is dc, continuous corona (recurring discharges) usually requires a higher voltage than when the stres

41、s is ac. The overvoltage necessary to establish continuous corona with dc applied will depend largely on the resistance of the insulation through which the charge must dissipate to reestablish the stress. This means that in apparatus where dc stress alone is characteristic, the corona dis- charges s

42、hould be measured with dc voltage applied. Caution should be used when the ap- plied voltage exceeds the peak working voltage of the transformer, since the ratio of the corona inception voltage to the insdation breakdown voltage may be very close to unity. However, this ratio may be as low as 0.5 wh

43、en the applied voltage is ac. 5.2.2.2 Testing With Combined DC and AC Voltage. When the voltage stress is combined dc and ac, continuous corona discharges will be due to the peak-to-peak voltage (calculated by summing the dc and peak ac voltages) and therefore will occur as if due to an ac voltage o

44、f the same peak-to-peak value. This means that in transformers characterized by combined ac and dc stress, measurements should be made using ac test voltage whose magnitude is determined with a peak-to-peak voltmeter (see 6.7). 6.25 Corona Discharge Pulse Rise Time. The corona discharge pulse voltag

45、e is as- sumed to have a sufficiently high rate of in- crease that its initial distribution throughout the circuit is controlled by the circuit capaci- tances. 6.2.4 Circuit Response. The response of the circuit, which includes the insulation system, to frequencies and their harmonics may com- plica

46、te corona discharge tests. Square waves, unidirectional pulses, rapid switching, or high frequencies will produce stress patterns. The application of test voltages below rated de- sign frequencies is generally valid, but caution must be observed when these voltages 7 IEEE Std4361991 JEEE GUIDE FOR M

47、AKING CORONA (PARTIAL DISCHARGE) are applied by induction so as not to saturate the core. 5.3 Signal-to-Noise Ratio. A minimum sig- nal-to-noise ratio of 2 to 1 should be established by reducing all electromagnetic interference, regardless of its origin, to less than one half of the amplitude of the

48、 minimum corona dis- charge level to be detected. 5.4 Discrimination Device Sensitivity. It should be demonstrated that equipment incor- porating discrimination devices (circuitry intended to isolate and identify corona dis- charges) does in fact discriminate between the minimum level specified for

49、discharges in the unit under test and the interference otherwise present in the test system. 6. Apparatus The equipment required for quantitative corona (partial discharge) measurements typ- ically includes the following: a test voltage supply, a coupling capacitor, a corona detector (frequently a single instrument combining an amplifier and an oscilloscope), a coupling impedance, a calibration pulse generator, cal- ibration coupling circuitry that often includes a calibration capacitor, and the transformer under test. Figures 1 and 2 show two of the sev- eral corona discharge measurem