IEEE 62-1978 - IEEE Guide for Field Testing Power Apparatus Insulation.pdf

1、IEEE Std 62-1978 (Revision of IEEE Std 62-1958) IEEE Guide for Field Testing Power Apparatus Insulation ublished by The Institute of Electrical and Electronics Engineers, Inc 345 East 47th Street, New York, NY 10017, USA cember 14, 1978 SH07203 IEEE Std 62-1978 (Revision of IEEE Std 62-1958) IEEE Gu

2、ide for Field Testing Power Apparatus Insulation Sponsor Power System Instrumentation and Measurement Committee of the IEEE Power Engineering Society Copyright 1978 by The Institute of Electrical and Electronics Engineers, Inc No part of this publication may be reproduced in any form, in an electron

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11、 the matter has previously received formal consideration. Comments on standards and requests for interpretations should be ad- dressed to: Secretary, IEEE Standards Board 345 East 47th Street New York, NY 10017 USA Foreword (This Foreword is not a part of IEEE Std 62-1978, Guide for Field Testing Po

12、wer Apparatus Insulation,) Factory tests assure the initial quality and condition of power apparatus insulation. During ship- ment, installation, and service, the apparatus is subject to influences that may affect the insulation and shorten its useful life. As a result, apparatus insulation is teste

13、d in the field from time to time to determine its suitability for continued service and to detect deterioration which often can be checked or corrected by suitable maintenance procedures. The variety of test methods and equipment used for the assessment of insulation quality neces- sitates the restr

14、iction of this guide to a general description of the more commonly used methods. An attempt has been made to supply sufficient information to identify those tests more applicable to a given situation and to provide references to a more detailed coverage. This guide was first published in April 1958

15、as AIEE Std 62, Recommended Guide for Making Dielectric Measurements in the Field. This revision is the first since that time. Withstand tests have been given greater coverage and the material on measurement of insulation characteristics reflects experience gained in the intervening years. This revi

16、sion has been prepared by a Working Group under the sponsorship of the High Voltage Testing Techniques Subcommittee of the IEEE Power Systems Instrumentation and Measurements Committee. The assistance of A. F. Rohlfs, Chairman, and other members of the High Voltage Test- ing Techniques Subcommittee,

17、 is gratefully acknowledged. At the time of approval of this standard the membership of the Working Group was as follows: E. H. Povey, Chairman L. Bucklew E. B. Curdts H. E. Foelker J. T. LaForte A. L. McKean J. R. Johnston, Secretary 0. Petersens E. F. Rodia B. F. Slingduff G. M. L. Sommerman L. R.

18、 Sharpe Approved September 8, 1977 IEEE Standards Board William R. Kruesi, Chairman William E. Andrus Jean Jacques Archambault Mark Barber Edward J. Cohen Warren H. Cook Louis Costrell R. L. Curtis David B. Dobson Irvin N. Howell, Jr., Vice Chairman Ivan G. Easton, Secretary R. 0. Duncan Charles W.

19、Flint Jay Forster Ralph I. Hauser Joseph L. Koepfinger Irving Kolodny Benjamin J. Leon Thomas J. Martin Donald T. Michael Voss A, Moore William S. Morgan William J. Neiswender Ralph M. Showers Robert A. Soderman Leonard W. Thomas, Sr. B. W. Whittington Contents PAGE 1 . Scope . 6 SECTION 2 . Safety

20、. 6 2.1 Personnel . 6 2.2 Apparatus . 6 . . 3 . Withstand Voltage Tests 6 3.1 Description 6 3.2 Significance . 7 3.3 Elementary Theory 7 3.4 Comparison of Tests 8 3.5 Environmental Influences 8 . . . 3.6 TestEquipment . 8 4 . Potential-Distribution Tests 9 . . . 4.1 Description 9 4.2 Significance 9

21、4.3 Equipment . 9 4.4 Comparison of Methods 9 4.5 Environmental Influences 9 9 5.1 General . 9 5.3 Measuring Methods 10 5.4 Environmental Influences . 11 6 . Measurement of Dielectric Characteristics 11 6.1 General . 11 6.3 Insulation Resistance . 11 6.4 Polarization Index 12 6.6 Dielectric Loss 13

22、6.8 Environmental Influences . 13 14 7.1 Rotating Machinery 14 7.3 Insulated Conductors (Cables) 17 7.5 Lightning Arresters 19 7.6 Capacitors . 20 7.7 Insulators . 20 7.9 Insulating Fluids 21 8 . Applicable Documents 22 8-.2 Withstand Voltage Tests 22 22 8.4 Dielectric Characteristics 22 . . . 5 . P

23、artial-Discharge (Corona) Tests 5.2 Significance . 10 . . 6.2 Significance . 11 6.5 Capacitance . 12 6.7 Power Factor, Dissipation Factor . 13 6.9 TestEquipment . 14 7.2 Transformers, Regulators, and Reactors . 16 7.4 Switchge ar . 18 7.8 Bushings . 20 8.1 Safety . 22 8.5 Rotating Machinery Insulati

24、on . 22 . . . . 7 . Tests on Specific Apparatus . . . . . 8.3 Partial-Discharge (Corona) Tests . . SECTION PAGE 8.6 Transformer Insulation . 22 8.7 Conductor (Cable) Insulation . 23 8.8 Capacitors . 23 8.9 Liquid Insulation . 23 Fig 1 Effect of Time on Withstand Voltage . 7 Fig 2 Effect of Absorptio

25、n on Measured Insulation Resistance . 12 Fig 3 Effect at Frequency on Loss Factor and Dielectric Constant . 12 FIGURES APPENDIXES Appendix A . Shielding of Equipment for the Measurement of Insulation Characteristics . 24 A1 . General . 24 A2 . Basic Shielding Systems 24 Appendix B . Measurement Tech

26、niques for the Analysis of Complex Insulation Systems . 28 B2 . Determination of the Characteristics of an Individual Component . 28 B4 . MethodB . 32 B5 . MethodC . 32 . B1 . Simple and Complex Systems . 28 B3 . MethodA . 28 APPENDIX FIGURES Fig A1 Elementary Measuring Circuit . 25 Fig A2 Grounded-

27、Guard Shield . 26 Fig A3 Hot-Guard Shield . 26 Fig A4 Cold-Guard Shield . 26 Fig A5 Double-Shielded Circuit . 27 Fig A6 Shielded Bridge Circuit with Guard Balance . 27 APPENDIX TABLES TableB1 . MethodA . 29 TableB2 . MethodB . 30 TableB3 . MethodC . 31 IEEE Guide for Field Testing Power Apparatus In

28、sulation 1. Scope This guide discusses the significance of various types of tests commonly employed to evaluate the insulation of power apparatus in the field, where environmental conditions cannot readily be controlled; the equipment and techniques required for each type of test; problems peculiar

29、to field testing, and methods of dealing with these problems; and the application of field tests to specific types of power apparatus. 2. Safety 2.1 Personnel 2.1.1 Hazards. Insulation tests in the field can present a hazard to personnel unless suit- able precautions are taken. Apparatus or cir- cui

30、ts to be made available to test personnel must be disconnected from the power system. Typical safety procedures call for a visual check of the disconnection or, when this is not possible, a check with a voltage indicator. Grounds are then applied. Personnel are usually instructed to treat all ungrou

31、nded apparatus as energized. 2.1.1 Ground Connection. Grounds may be removed to permit application of test voltage. When feasible, it is preferable to retain the ground connection during the tests and to pro- vide between the ground and the apparatus under test a second disconnection of sufficient c

32、learance for the test voltage (see 6.8.3.2). 2.1.3 Precautions. When the test voltage is over a few volts, precautions should be taken to prevent personnel from contacting the ener- gized circuit. An observer may be stationed to warn approaching personnel and may be sup- plied with means to deenergi

33、ze the circuit. The means may include a switch to shut off the power source and, particularly in case of a di- rect test voltage, provisions for grounding the circuit until all stored charges are dissipated. 2.1.4 Warning Signs and Barriers. The test area may be marked off with signs and easily visi

34、ble tape. Warning signs should conform to the requirements of governing bodies such as the Occupational Safety and Health Adminis- tration (OSHA) in the United States. 2.2 Apparatus 2.2.1 Consequences of Failure. When the test voltage to be applied to apparatus insulation exceeds the normal operatin

35、g value, there exists the possibility of failure under test. Be- fore applying the test, consideration should be given to the time, material, and labor required for a possible repair. If failure could result in fire, fire-fighting equipment should be available. 2.2.2 Overvoltage. In the conduct of h

36、igh- voltage tests the voltage may accidently exceed the desired maximum. A sphere gap, adjusted to spark over at a voltage slightly above the de- sired maximum, may be connected across the voltage source. By selecting the proper value of series resistor, the gap may be used to provide a warning sig

37、nal, to inhibit further rise in the test voltage, or to activate an overcurrent circuit breaker in the power supply circuit. 2.2.3 Graded Insulation. When an alternating test voltage is applied to a short-circuited winding, or when a direct test voltage is used, the insulation of the entire winding is subject to this test voltage. When the insulation level of the winding is graded from one end to the other, the magnitude