1、BSI Standards PublicationElectrical insulating materials and systems A.C. voltage endurance evaluationBS EN 61251:2016National forewordThis British Standard is the UK implementation of EN 61251:2016. It is identical to IEC 61251:2015. It supersedes DD IEC/TS 61251:2008 which is withdrawn.The UK part
2、icipation in its preparation was entrusted to TechnicalCommittee GEL/112, Evaluation and qualification of electrical insulatingmaterials and systems.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the n
3、ecessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 87580 9ICS 17.220.99; 29.035.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This Britis
4、h Standard was published under the authority of theStandards Policy and Strategy Committee on 31 March 2016.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 61251:2016EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 61251 February 2016 ICS 17.220.99; 29.035.0
5、1 English Version Electrical insulating materials and systems - A.C. voltage endurance evaluation (IEC 61251:2015) Systmes et matriaux isolants lectriques - valuation de lendurance a la tension alternative (IEC 61251:2015) Elektrische Isolierstoffe und -systeme - Ermittlung der Wechselspannungsbestn
6、digkei (IEC 61251:2015) This European Standard was approved by CENELEC on 2015-12-23. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date li
7、sts 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 Standard exists in three official versions (English, French, German). A version in any other language made by translation
8、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 the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark,
9、 Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Commi
10、ttee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENE
11、LEC Members. Ref. No. EN 61251:2016 E BS EN 61251:2016EN 61251:2016 2 European foreword The text of document 112/338/FDIS, future edition 1 of IEC 61251, prepared by IEC/TC 112 “Evaluation and qualification of electrical insulating materials and systems“ was submitted to the IEC-CENELEC parallel vot
12、e and approved by CENELEC as EN 61251:2016. 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) 2016-09-23 latest date by which the national standards conflicting with the do
13、cument have to be withdrawn (dow) 2018-12-23 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 the Intern
14、ational Standard IEC 61251:2015 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 60243-1 NOTE Harmonized as EN 60243-1. IEC 60243-2 NOTE Harmonized as EN 60243-2.
15、IEC 60243-3 NOTE Harmonized as EN 60243-3. IEC 60343 NOTE Harmonized as EN 60343. IEC 61649 NOTE Harmonized as EN 61649. BS EN 61251:2016EN 61251:2016 3 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following documents, in
16、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 (including any amendments) applies. NOTE 1 When an International Public
17、ation has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here: www.cenelec.eu. Publication Year Title EN/HD Year IEC 62539 - Guide for the statisti
18、cal analysis of electrical insulation breakdown data - - BS EN 61251:2016 2 IEC 61251:2015 IEC 2015 CONTENTS FOREWORD . 3 INTRODUCTION . 5 1 Scope 6 2 Normative references 6 3 Terms, definitions and symbols 6 3.1 Terms and definitions 6 3.2 Symbols 7 4 Voltage endurance 7 4.1 Voltage endurance testi
19、ng 7 4.2 Electrical stress 7 4.3 Voltage endurance (VE) graph 8 4.4 Short-time electric strength . 8 4.5 Voltage endurance coefficient (VEC) . 9 4.6 Differential VEC (nd) . 9 4.7 Electrical threshold stress (Et) 9 4.8 Voltage endurance relationship . 10 5 Test methods . 11 5.1 Introductory remarks .
20、 11 5.2 Tests at constant stress 11 5.2.1 Conventional VE test . 11 5.2.2 Diagnostic measurements 12 5.2.3 Detection of an electrical threshold 12 5.3 Tests at higher frequency 12 5.4 Progressive stress tests 13 5.5 Preliminary tests to determine the initial part of the VE line . 15 5.6 Recommended
21、test procedure 15 6 Evaluation of voltage endurance 15 6.1 Significance of the VEC 15 6.2 Significance of the electrical threshold stress 16 6.3 Dispersion of data and precision requirements 16 6.4 Presentation of the results 16 Annex A (informative) The Weibull distribution . 18 A.1 Weibull distrib
22、ution times to dielectric breakdown . 18 A.2 Weibull distribution dielectric breakdown stresses . 18 A.3 Generalized Weibull distribution of the dielectric breakdown stresses . 18 A.4 Inverse power model for the time to dielectric breakdown . 19 Bibliography 20 Figure 1 General voltage endurance lin
23、e 8 Figure 2 Determination of the differential VEC ndat a generic point P of the VE line 9 Figure 3 Plotting the VE line in a progressive stress test using different rates of stress rise . 14 BS EN 61251:2016IEC 61251:2015 IEC 2015 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ ELECTRICAL INSULATING
24、MATERIALS AND SYSTEMS AC VOLTAGE ENDURANCE EVALUATION FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operat
25、ion on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “
26、IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this prepar
27、ation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consen
28、sus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees. 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts ar
29、e made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications tr
30、ansparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC itself does not provide any attestation of conformity. Independen
31、t certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 6) All users should ensure that they have the latest edition of this publication. 7) No liabil
32、ity shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (includ
33、ing legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications. 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of t
34、his publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights. International Standard IEC 61251 has been prepared by IEC technical commit
35、tee 112: Evaluation and qualification of electrical insulating materials and systems. This first edition of IEC 61251 cancels and replaces the second edition of IEC TS 61251, published in 2008. This edition constitutes a technical revision. This edition includes the following significant technical c
36、hanges with respect to the second edition of IEC TS 61251: a) upgrade from Technical Specification to an International Standard; b) clarification of issues raised since publication of IEC TS 61251. BS EN 61251:2016 4 IEC 61251:2015 IEC 2015 The text of this standard is based on the following documen
37、ts: FDIS Report on voting 112/338/FDIS 112/347/RVD Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. The committee has decided that t
38、he contents of this publication will remain unchanged until the stability date indicated on the IEC website under “http:/webstore.iec.ch“ in the data related to the specific publication. At this date, the publication will be reconfirmed, withdrawn, replaced by a revised edition, or amended. BS EN 61
39、251:2016IEC 61251:2015 IEC 2015 5 INTRODUCTION This International Standard covers insulating materials and systems. Voltage endurance tests are used to compare and evaluate insulating materials and systems. It is complex to determine the capability of electrical insulating materials and systems to e
40、ndure a.c. voltage stress. The results of voltage endurance tests are influenced by many factors. Therefore this International Standard can be considered as an attempt to present a unified view of voltage endurance for simplified planning and analysis. BS EN 61251:2016 6 IEC 61251:2015 IEC 2015 ELEC
41、TRICAL INSULATING MATERIALS AND SYSTEMS AC VOLTAGE ENDURANCE EVALUATION 1 Scope This International Standard describes many of the factors involved in voltage endurance tests on electrical insulating materials and systems. It describes the voltage endurance graph, lists test methods illustrating thei
42、r limitations and gives guidance for evaluating the sinusoidal a.c. voltage endurance of insulating materials and systems from the results of the tests. This International Standard is applicable over the voltage frequency range 20 Hz to 1 000 Hz. The general principles can also be applicable to othe
43、r voltage shapes, including impulse voltages. The terminology to be used in voltage endurance is defined and explained. 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, on
44、ly the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 62539, Guide for the statistical analysis of electrical insulation dielectric breakdown data 3 Terms, definitions and symbols 3.1 Terms and definitions For the
45、purposes of this document, the following terms and definitions apply. 3.1.1 voltage endurance VE measures of the capability of a solid insulating material to endure voltage Note 1 to entry: In this International Standard, only a.c. voltage is considered. Note 2 to entry: This note only applies to th
46、e French language. 3.1.2 life time to dielectric breakdown 3.1.3 voltage endurance coefficient VEC numerical value of the reciprocal of the slope of a straight line log-log VE plot Note 1 to entry: This note only applies to the French language. 3.1.4 specimen representative test object for assessing
47、 the value of one or more physical properties BS EN 61251:2016IEC 61251:2015 IEC 2015 7 3.1.5 sample group of nominally identical specimens extracted randomly from the same manufacturing batch 3.2 Symbols c, c constants in the inverse-power model E electric stress Eo short-time electric strength Et
48、electric threshold stress f frequency h, k constants in the exponential model L life m scale parameter in the Weibull distribution (one variable) M scale parameter in the generalized Weibull distribution (two variables) n exponent of stress in the inverse-power model coinciding with the VEC nd diffe
49、rential VEC R dimensional ratio t time tc time to dielectric breakdown at constant stress to time to dielectric breakdown at constant stress Eotp time to dielectric breakdown with progressive stress tan dissipation factor scale parameter (63,2 percentile) in the Weibull distribution of times to dielectric breakdown at constant stress shape parameter in the Weibull distribution of times to dielectric breakdown at constant stress shape parameter of the Weibull distribution of the dielectr
