EN 60076-3-2013 en Power transformers - Part 3 Insulation levels dielectric tests and external clearances in air.pdf

1、BSI Standards PublicationPower transformersPart 3: Insulation levels, dielectric tests and external clearances in airBS EN 60076-3:2013National forewordThis British Standard is the UK implementation of EN 60076-3:2013. It isidentical to IEC 60076-3:2013. It supersedes BS EN 60076-3:2001, which willb

2、e withdrawn on 4 September 2016.The UK participation in its preparation was entrusted to TechnicalCommittee PEL/14, Power transformers.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provi

3、sions ofa contract. Users are responsible for its correct application. The British Standards Institution 2013.Published by BSI Standards Limited 2013ISBN 978 0 580 72472 5ICS 29.180Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published und

4、er the authority of theStandards Policy and Strategy Committee on 31 December 2013.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 60076-3:2013EUROPEAN STANDARD EN 60076-3 NORME EUROPENNE EUROPISCHE NORM November 2013 CENELEC European Committee for Electrotechni

5、cal Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref.

6、No. EN 60076-3:2013 E ICS 29.180 Supersedes EN 60076-3:2001 English version Power transformers - Part 3: Insulation levels, dielectric tests and external clearances in air (IEC 60076-3:2013) Transformateurs de puissance - Partie 3: Niveaux disolement, essais dilectriques et distances disolement dans

7、 lair (CEI 60076-3:2013) Leistungstransformatoren - Teil 3: Isolationspegel, Spannungsprfungen und uere Abstnde in Luft (IEC 60076-3:2013) This European Standard was approved by CENELEC on 2013-09-04. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the c

8、onditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member. This European Standar

9、d exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are th

10、e national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Polan

11、d, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 60076-3:2013EN 60076-3:2013 - 2 - Foreword The text of document 14/745/FDIS, future edition 3 of IEC 60076-3, prepared by IEC/TC 14 “Power transformers“ was submitted to the IEC-CENELEC paralle

12、l vote and approved by CENELEC as EN 60076-3:2013. The following dates are fixed: latest date by which the document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2014-06-04 latest date by which the national standards conflicting with

13、 the document have to be withdrawn (dow) 2016-09-04 This document supersedes EN 60076-3:2001. EN 60076-3:2013 includes the following significant technical changes with respect to EN 60073-3:2001: Three categories of transformer are clearly identified together with the relevant test requirements, the

14、se are summarised in Table 1. Switching impulse levels are defined for all Um72,5kV. The procedure for Induced voltage tests with PD has been revised to ensure adequate phase to phase test voltages. The AC withstand test has been redefined (LTAC instead of ACSD). Induced voltage tests are now based

15、on Ur rather than Um. New requirements for impulse waveshape (k factor) have been introduced. Tables of test levels have been merged and aligned with IEC 60071-1:2010. Additional test levels have been introduced for Um 800kV. A new Annex E has been introduced, which sets out the principles used in a

16、ssigning the tests, test levels and clearances in air. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of

17、the International Standard IEC 60076-3:2013 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated: IEC 60071-2 NOTE Harmonized as EN 60071-2. IEC 60076-4 NOTE Harmonized as

18、EN 60076-4. IEC 60214-1 NOTE Harmonized as EN 60214-1. IEC 61083-1 NOTE Harmonized as EN 61083-1. IEC 61083-2 NOTE Harmonized as EN 61083-2. IEC 62271-1 NOTE Harmonized as EN 62271-1. BS EN 60076-3:2013- 3 - EN 60076-3:2013 Annex ZA (normative) Normative references to international publications with

19、 their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document

20、(including any amendments) applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60050-421 International electrotechnical vocabulary (IEV) - Chapter 421: Power transformers and

21、reactors - - IEC 60060-1 High-voltage test techniques Part 1: General definitions and test requirements EN 60060-1 IEC 60060-2 High-voltage test techniques - Part 2: Measuring systems EN 60060-2 IEC 60071-1 Insulation co-ordination - Part 1: Definitions, principles and rules EN 60071-1 IEC 60076-1 P

22、ower transformers - Part 1: General EN 60076-1 IEC 60137 Insulated bushings for alternating voltages above 1 000 V EN 60137 IEC 60270 High-voltage test techniques - Partial discharge measurements EN 60270 BS EN 60076-3:2013 2 60076-3 IEC:2013 CONTENTS INTRODUCTION . 6 1 Scope . 7 2 Normative referen

23、ces 7 3 Terms and definitions . 7 4 General 8 5 Highest voltage for equipment and rated insulation level 10 6 Transformers with re-connectable windings . 11 7 Dielectric tests 12 7.1 Overview . 12 7.2 Test requirements 13 7.2.1 General . 13 7.2.2 Test voltage levels . 14 7.2.3 Test sequence . 17 7.3

24、 Test requirements for specific transformers . 17 7.3.1 Tests for transformers with Um 72,5 kV . 17 7.3.2 Tests on transformers with 72,5 kV 170 kV . 19 7.4 Assigning Umand test voltages to the neutral terminal of a winding . 20 7.4.1 Transformers with Um 72,5 kV 20 7.4.2 Transformers with Um 72,5 k

25、V 20 8 Dielectric tests on transformers that have been in service . 20 9 Insulation of auxiliary wiring (AuxW) 21 10 Applied voltage test (AV) . 21 11 Induced voltage tests (IVW and IVPD) 22 11.1 General . 22 11.2 Induced voltage withstand test (IVW) . 22 11.3 Induced voltage test with partial disch

26、arge measurement (IVPD) 23 11.3.1 General . 23 11.3.2 Test duration and frequency . 23 11.3.3 Test sequence . 23 11.3.4 Partial discharge (PD) measurement 24 11.3.5 Test acceptance criteria . 25 12 Line terminal AC withstand test (LTAC) . 25 13 Lightning impulse tests (LI, LIC, LIN, LIMT) . 26 13.1

27、Requirements for all lightning impulse tests . 26 13.1.1 General . 26 13.1.2 Tap positions . 26 13.1.3 Records of tests . 26 13.1.4 Test connections 27 13.2 Full wave lightning impulse test (LI) . 28 13.2.1 Wave shape, determination of test voltage value and tolerances 28 13.2.2 Tests on transformer

28、s without non-linear elements . 29 13.2.3 Tests on transformers with non-linear elements 30 13.3 Chopped wave lightning impulse test (LIC) . 31 BS EN 60076-3:201360076-3 IEC:2013 3 13.3.1 Wave shape. 31 13.3.2 Tests on transformers without non-linear elements . 31 13.3.3 Tests on transformers with n

29、on-linear elements 32 13.4 Lightning impulse test on a neutral terminal (LIN) . 33 13.4.1 General . 33 13.4.2 Waveshape 33 13.4.3 Test sequence . 34 13.4.4 Test criteria . 34 14 Switching impulse test (SI) 34 14.1 General . 34 14.2 Test connections . 34 14.3 Waveshape . 35 14.4 Test sequence . 35 14

30、.5 Test criteria . 35 15 Action following test failure . 36 16 External clearances in air 36 16.1 General . 36 16.2 Clearance requirements . 37 Annex A (informative) Application guide for partial discharge measurements on transformers . 40 Annex B (informative) Overvoltage transferred from the high-

31、voltage winding to a low-voltage winding . 45 Annex C (informative) Information on transformer insulation and dielectric tests to be supplied with an enquiry and with an order 47 Annex D (informative) Neutral insulation voltage level calculation . 50 Annex E (informative) Basis for dielectric tests,

32、 insulation levels and clearances 53 Bibliography 56 Figure 1 Time sequence for the application of test voltage for induced voltage test with partial discharge measurement (IVPD) 24 Figure A.1 Calibration circuit for partial discharge measurement using the test tap of condenser type bushing. 41 Figu

33、re A.2 Circuit for partial discharge measurement using a high-voltage coupling capacitor . 42 Figure B.1 Equivalent circuit for capacitive transfer of overvoltage 46 Table 1 Requirements and tests for different categories of windings 14 Table 2 Test voltage levels (1 of 2) . 15 Table 3 Test voltage

34、levels used in special cases . 16 Table 4 Minimum clearances in air (1 of 2) . 38 BS EN 60076-3:2013 6 60076-3 IEC:2013 INTRODUCTION This part of IEC 60076 specifies the insulation requirements and the corresponding insulation tests with reference to specific windings and their terminals. It also re

35、commends external clearances in air (Clause 16). The insulation levels and dielectric tests which are specified in this standard apply to the internal insulation only. Whilst it is reasonable that the rated withstand voltage values which are specified for the internal insulation of the transformer s

36、hould also be taken as a reference for its external insulation, this may not be true in all cases. A failure of the non-self-restoring internal insulation is catastrophic and normally leads to the transformer being out of service for a long period, while an external flashover may involve only a shor

37、t interruption of service without causing lasting damage. Therefore, it may be that, for increased safety, higher test voltages are specified by the purchaser for the internal insulation of the transformer than for the external insulation of other components in the system. When such a distinction is

38、 made, the external clearances should be adjusted to fully cover the internal insulation test requirements. Annex E sets out some of the principles used in assigning the tests, test levels and clearances in air to the transformer according to the highest voltage for equipment Um. BS EN 60076-3:20136

39、0076-3 IEC:2013 7 POWER TRANSFORMERS Part 3: Insulation levels, dielectric tests and external clearances in air 1 Scope This International Standard applies to power transformers as defined by and in the scope of IEC 60076-1. It gives details of the applicable dielectric tests and minimum dielectric

40、test levels. Recommended minimum external clearances in air between live parts and between live parts and earth are given for use when these clearances are not specified by the purchaser. For categories of power transformers and reactors which have their own IEC standards, this standard is applicabl

41、e only to the extent in which it is specifically called up by cross reference in the other standards. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cit

42、ed applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050-421, International Electrotechnical Vocabulary (IEV) Chapter 421: Power transformers and reactors IEC 60060-1, High-voltage test techniques Part 1: General definitions and

43、test requirements IEC 60060-2, High-voltage test techniques Part 2: Measuring systems IEC 60071-1, Insulation co-ordination Part 1: Definitions, principles and rules IEC 60076-1, Power transformers Part 1: General IEC 60137, Insulated bushings for alternating voltages above 1 000 V IEC 60270, High-v

44、oltage test techniques Partial discharge measurements 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60076-1, IEC 60050-421 and the following apply. 3.1 highest voltage for equipment applicable to a transformer winding Umhighest r.m.s. phase-to-phas

45、e voltage in a three-phase system for which a transformer winding is designed in respect of its insulation BS EN 60076-3:2013 8 60076-3 IEC:2013 3.2 rated voltage of a winding Urvoltage assigned to be applied, or developed at no-load, between the terminals of an untapped winding, or a tapped winding

46、 connected on the principal tapping, for a three-phase winding it is the voltage between line terminals Note 1 to entry: The rated voltages of all windings appear simultaneously at no-load when the voltage applied to one of them has its rated value. Note 2 to entry: For single-phase transformers int

47、ended to be connected in star to form a three-phase bank or to be connected between the line and the neutral of a three phase system, the rated voltage is indicated as the phase-to-phase voltage, divided by 3 , for example 3/400 kV. Note 3 to entry: For single phase transformers intended to be conne

48、cted between phases of a network, the rated voltage is indicated as the phase-to-phase voltage. Note 4 to entry: For the series winding of a three-phase series transformer, which is designed as an open winding, the rated voltage is indicated as if the windings were connected in star. SOURCE: IEC 600

49、76-1:2011, 3.4.3 3.3 rated insulation level set of rated withstand voltages which characterise the dielectric strength of the insulation 3.4 rated withstand voltage value of the assigned test voltage applied in one of the standard dielectric tests that proves that the insulation complies with the assigned test voltage 3.5 uniform insulation of a transformer winding insulation of a transformer winding that has all its ends connected to terminals with the same rated insulatio