1、BSI Standards PublicationElectrical insulating materials and systems General method of evaluation of electrical endurance under repetitive voltage impulsesBS EN 62068:2013National forewordThis British Standard is the UK implementation of EN 62068:2013. It is identical to IEC 62068:2013. It supersede
2、s BS EN 62068-1:2003 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee GEL/112, Evaluation and qualification of electrical insulatingmaterials and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.Thi
3、s publication does not purport to include all the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2013.Published by BSI Standards Limited 2013ISBN 978 0 580 77740 0ICS 29.080.30Compliance with a British Standard cannot confer im
4、munity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 October 2013.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 62068:2013EUROPEAN STANDARD EN 62068 NORME EUROPENNE EUROPISCHE
5、NORM September 2013 CENELEC European Committee for Electrotechnical 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 for
6、m and by any means reserved worldwide for CENELEC members. Ref. No. EN 62068:2013 E ICS 29.080.30 Supersedes EN 62068-1:2003 English version Electrical insulating materials and systems - General method of evaluation of electrical endurance under repetitive voltage impulses (IEC 62068:2013) Matriaux
7、et systmes disolation lectriques - Mthode gnrale dvaluation de lendurance lectrique soumise des impulsions de tension appliques priodiquement (CEI 62068:2013) Elektrische Isolierstoffe und Isoliersysteme - Allgemeines Verfahren zur Bewertung der elektrischen Lebensdauer bei Beanspruchung mit sich wi
8、ederholenden Spannungsimpulsen (IEC 62068:2013) This European Standard was approved by CENELEC on 2013-04-15. 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 a
9、lteration. 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 Standard exists in three official versions (English, French, German). A version in any other langu
10、age 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 the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the
11、Czech Republic, Denmark, 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
12、 Kingdom. BS EN 62068:2013EN 62068:2013 - 2 - Foreword The text of document 112/234/FDIS, future edition 1 of IEC 62068, prepared by IEC TC 112 “Evaluation and qualification of electrical insulating materials and systems“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 6
13、2068:2013. 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) 2014-03-27 latest date by which the national standards conflicting with the document have to be withdrawn (dow)
14、 2016-04-15 This document supersedes EN 62068-1:2003. EN 62068:2013 includes the following significant technical changes with respect to EN 62068-1:2003: The main changes with regard to EN 62068-1:2003 concern the terms and definitions which are now aligned, in part, on IEC/TS 61934 and CLC/TS 60034
15、-18-42. 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 International Standard IEC 62068:2013 was a
16、pproved 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/TS 60034-18-42:2008 NOTE Harmonised as CLC/TS 60034-18-42:2011 (not modified). IEC 60505:2011 NOTE Harmonised as EN 605
17、05:2011 (not modified). IEC 60270:2000 NOTE Harmonised as EN 60270:2001 (not modified). BS EN 62068:2013- 3 - EN 62068:2013 Annex ZA (normative) Normative references to international publications with their corresponding European publications The following documents, in whole or in part, are normati
18、vely 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 When an international publication has been modified by comm
19、on modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 62539 - Guide for the statistical analysis of electrical insulation breakdown data - - BS EN 62068:2013 2 62068 IEC:2013 CONTENTS 1 Scope . 5 2 Normative references . 5 3 Terms and definitions . 5
20、 4 General test procedures . 8 4.1 Overview . 8 4.2 Test object 9 4.3 Screening test method . 9 4.3.1 General . 9 4.3.2 Test procedure 9 4.3.3 RPDIV and RPDEV measurements 9 4.3.4 Data processing 9 4.3.5 Evaluation . 10 4.4 Endurance test method 10 4.4.1 Reference EIS . 10 4.4.2 Comparison test 10 5
21、 Test impulse-voltage characteristics . 11 Annex A (informative) Impulse ageing 12 Bibliography 15 Table 1 Test impulse-voltage characteristics 11 BS EN 62068:201362068 IEC:2013 5 ELECTRICAL INSULATING MATERIALS AND SYSTEMS GENERAL METHOD OF EVALUATION OF ELECTRICAL ENDURANCE UNDER REPETITIVE VOLTAG
22、E IMPULSES 1 Scope This International Standard applies to electrical equipment, regardless of voltage, containing an insulation system, which is connected to an electronic power supply, and requires an evaluation of insulation endurance under repetitive voltage impulses. This standard proposes a gen
23、eral test procedure to facilitate screening of electrical insulating materials (EIM) and systems (EIS) and to achieve a relative evaluation of insulation endurance under conditions of repetitive impulses. 2 Normative references The following documents, in whole or in part, are normatively referenced
24、 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. IEC 62539, Guide for the statistical analysis of electrical insulation breakdow
25、n data 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 electrical insulating material EIM material with negligibly low electric conductivity, used to separate conducting parts at different electrical potentials SOURCE: IEC 60505:2011, definit
26、ion 3.1.2 3 23.2 electrical insulation system EIS insulating structure containing one or more electrical insulating materials (EIM) together with associated conducting parts employed in an electrotechnical device SOURCE: IEC 60505:2011, definition 3.1.1 2 3.3 candidate EIS EIS under evaluation to de
27、termine its electrical endurance when exposed to repetitive voltage impulses _ 2Figures in square brackets refer to the Bibliography. BS EN 62068:2013 6 62068 IEC:2013 3.4 reference EIS evaluated and established EIS with either a known service experience or a known comparative functional evaluation
28、under repetitive voltage impulses 3.5 partial discharge PD electric discharge that only partially bridges the insulation between electrical conductors SOURCE: IEC 60270:2000, definition 3.1 modified 4 the word “localized“ (electrical discharge) omitted from source definition, and definition shortene
29、d to omit reference to “which can or can not occur adjacent to a conductor“. Also the three NOTES after the term have been omitted 3.6 partial discharge pulse current pulse in an object under test that results from a partial discharge occurring within the object under test Note 1 to entry: The pulse
30、 is measured using suitable detector circuits, which have been introduced into the test circuit for the purpose of the test. Note 2 to entry: A detector in accordance with the provisions of this standard produces a current or a voltage signal at its output related to the PD pulse at its input. SOURC
31、E: IEC/TS 61934:2011, definition 3.3, modified In Note 2 to entry, “provisions“ of this technical specification“ edited to read “of this standard“ 3.7 repetitive partial discharge inception voltage RPDIV minimum peak-to-peak impulse voltage at which more than five PD pulses occur on ten voltage impu
32、lses of the same polarity Note 1 to entry: This is a mean value for the specified test time and a test arrangement where the voltage applied to the test object is gradually increased from a value at which no partial discharge can be detected. SOURCE: IEC/TS 61934:2011, definition 3.4 3.8 repetitive
33、partial discharge extinction voltage RPDEV maximum peak-to-peak impulse voltage at which less than five PD pulses occur on ten voltage impulses of the same polarity Note 1 to entry: This is a mean value for the specified test time and a test arrangement where the voltage applied to the test object i
34、s gradually decreased from a value at which PD have been detected. SOURCE: IEC/TS 61934:2011, definition 3.5 3.9 partial discharge inception voltage PDIV lowest voltage at which partial discharges are initiated in the test arrangement, when the voltage applied to the object is gradually increased fr
35、om a lower value at which no such discharges are observed BS EN 62068:201362068 IEC:2013 7 3.10 partial discharge extinction voltage PDEV highest voltage at which partial discharges are extinguished in the test arrangement, when the voltage applied to the object is gradually decreased from a higher
36、value at which such discharges are observed 3.11 unipolar impulse voltage impulse, the polarity of which is either positive or negative 3.12 bipolar impulse voltage impulse, the polarity of which alternates from positive to negative or vice versa 3.13 impulse-voltage polarity polarity of the applied
37、 impulse, with respect to earth 3.14 impulse-voltage repetition rate inverse of the time between two successive impulses when the time intervals are the same, whether unipolar or bipolar 3.15 impulse rise time 1,25 times the time interval between 10 % and 90 % of the zero-to-peak impulse voltage, on
38、 the leading edge of the impulse 3.16 impulse decay time time interval between the instants at which the instantaneous value of an impulse decreases from a specified upper value to a specified lower value Note 1 to entry: Unless otherwise specified, the upper and lower values are fixed at 90 % and 1
39、0 % of the impulse magnitude. SOURCE: IEC/TS 61934:2011, definition 3.11 3.17 impulse width interval of time between the first and last instants at which the instantaneous value of an impulse reaches a specified fraction of impulse magnitude or a specified threshold SOURCE: IEC/TS 61934:2011, defini
40、tion 3.12 3.18 impulse duty cycle ratio, for a given time interval,of the impulse width to the total time SOURCE: IEC/TS 61934-2011, definition 3.13 3.19 peak partial discharge magnitude largest magnitude of any quantity related to PD pulses observed in a test object at a specified voltage following
41、 a specified conditioning and test BS EN 62068:2013 8 62068 IEC:2013 Note 1 to entry: For impulse voltage tests, the peak magnitude of the PD is the largest repeatedly occurring PD magnitude. SOURCE: IEC/TS 61934:2011, definition 3.14 3.20 rate of voltage rise 0,8 times the impulse-voltage magnitude
42、 divided by the time interval between the 10 % and 90 % magnitude of the zero-to-peak impulse voltage 3.21 voltage endurance coefficient VEC exponent of the inverse power model or exponential model, which together with the coefficient k, describes the relationship between life and voltage 3.22 life
43、either time or number of impulses to failure 4 General test procedures 4.1 Overview Clause 4 describes the general procedures for evaluating the ability of an EIS to resist deterioration due to repetitive impulse voltages. There are two methods, depending on the desired outcome: a) A screening test
44、can be carried out at a single test voltage to assess alternative EIMs or different physical constructions by comparison with the previously evaluated EIS. The purpose is to find the EIM (or construction) which yields better endurance. In addition, a single EIS can be evaluated at a single test volt
45、age under variable test conditions, such as different humidity, different impulse repetition rates, etc. to determine the effect of the variable. NOTE IEC/TS 60034-18-42 gives an example of a screening test for stator winding stress grading coating. b) An endurance test can be conducted to estimate
46、the relationship between impulse voltage and life for each EIS to be evaluated. The EIS is evaluated at several voltage levels, with the other conditions being usually constant. A possible relationship between voltage endurance and voltage magnitude can be represented by an inverse power law: L = kU
47、 n(1) where L is the time to failure or number of impulses to failure of the test object (at a given probability); U is the applied impulse voltage; n is the voltage endurance coefficient (VEC); k is a constant. Other relationships are also possible. For example, the exponential model is: L = Ae hU(
48、2) where A and h are constants. BS EN 62068:201362068 IEC:2013 9 The results from an impulse electrical endurance or screening test depend on a large number of factors in addition to the inherent capability of an EIS. These factors shall be specified and controlled in any impulse-ageing test. Annex
49、A reviews these factors. The following subclauses describe the general test procedures for impulse screening and endurance testing. The design and the number of the test object and the impulse-voltage characteristics depend on the EIS that is being modelled. 4.2 Test object The test object includes a conductor separated from the earth conductor by electrical insulation. A greater number of test objects are needed when greater statistical significance is required
