EN 60243-3-2014 en Electric strength of insulating materials - Test methods - Part 3 Additional requirements for 1 2 50 impulse tests.pdf

1、BSI Standards PublicationElectric strength of insulatingmaterials Test methodsPart 3: Additional requirements for 1,2/50 s impulse testsBS EN 60243-3:2014National forewordThis British Standard is the UK implementation of EN 60243-3:2014. It is identical to IEC 60243-3:2013. It supersedes BS EN 60243

2、-3:2002 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee GEL/112, Evaluation and qualification of electrical insulatingmaterials and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.This publication

3、 does not purport to include all the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2014.Published by BSI Standards Limited 2014ISBN 978 0 580 83185 0ICS 17.220.99; 29.035.01Compliance with a British Standard cannot confer immu

4、nity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 March 2014.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 60243-3:2014EUROPEAN STANDARD EN 60243-3 NORME EUROPENNE EUROPISCHE

5、NORM February 2014 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 2014 CENELEC - All rights of exploitation in any form

6、 and by any means reserved worldwide for CENELEC members. Ref. No. EN 60243-3:2014 E ICS 17.220.99; 29.035.01 Supersedes EN 60243-3:2001 English version Electric strength of insulating materials - Test methods - Part 3: Additional requirements for 1,2/50 s impulse tests (IEC 60243-3:2013) Rigidit di

7、lectrique des matriaux isolants - Mthodes dessai - Partie 3: Exigences complmentaires pour les essais aux ondes de choc 1,2/50 s (CEI 60243-3:2013) Elektrische Durchschlagfestigkeit von isolierenden Werkstoffen - Prfverfahren - Teil 3: Zustzliche Festlegungen fr 1,2/50 s Stospannungsprfungen (IEC 60

8、243-3:2013) This European Standard was approved by CENELEC on 2013-12-31. 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 lists and bibl

9、iographical 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 under the re

10、sponsibility 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, Estonia, Fi

11、nland, 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. BS EN 60243-3:2014EN 60243

12、-3:2014 - 2 - Foreword The text of document 112/246/CDV, future edition 3 of IEC 60243-3, prepared by IEC/TC 112 “Evaluation and qualification of electrical insulation materials and systems“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 60243-3:2014. The following date

13、s 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) 2014-09-30 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2016-12-31 This document sup

14、ersedes EN 60243-3:2001. This standard shall be read in conjunction with EN 60243-1. 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. E

15、ndorsement notice The text of the International Standard IEC 60243-3:2013 was approved by CENELEC as a European Standard without any modification. BS EN 60243-3:2014- 3 - EN 60243-3:2014 Annex ZA (normative) Normative references to international publications with their corresponding European publica

16、tions 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 (including any amendments) applies. N

17、OTE 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 60243-1 2013 Electric strength of insulating materials - Test methods - Part 1: Tests at power frequencies EN 60243-1 2013 BS EN 6024

18、3-3:2014 2 60243-3 IEC:2013 CONTENTS 1 Scope 5 2 Normative references . 5 3 Terms and definitions 5 4 Significance of the test . 6 5 Electrodes and test specimens . 7 6 Conditioning before tests . 7 7 Surrounding medium 7 8 Electrical apparatus . 7 8.1 Voltage source . 7 8.2 Voltage measurement 8 9

19、Procedure 8 10 Application of voltage . 8 10.1 Breakdown test 8 10.2 Proof tests . 8 11 Criterion of breakdown . 9 12 Number of tests . 9 13 Report . 9 Figure 1 Full impulse-voltage wave . 6 BS EN 60243-3:201460243-3 IEC:2013 5 ELECTRIC STRENGTH OF INSULATING MATERIALS TEST METHODS Part 3: Additiona

20、l requirements for 1,2/50 s impulse tests 1 Scope This part of IEC 60243 gives requirements additional to those in IEC 60243-1 for the determination of the electric strength of solid insulating materials under 1,2/50 s impulse voltage stress. 2 Normative references The following documents, in whole

21、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. IEC 60243-1:2013, Electric strength of in

22、sulating materials Test methods Part 1: Tests at power frequencies 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60243-1, together with the following, apply. 3.1 full impulse-voltage wave aperiodic transient voltage that rises rapidly to a maximum

23、value, then falls less rapidly to zero (see Figure 1) 3.2 peak value (of an impulse-voltage wave) UPmaximum value of voltage 3.3 virtual peak value (of an impulse-voltage wave) U1value derived from a recording of an impulse-voltage wave on which high-frequency oscillations, or overshoot of a limited

24、 magnitude, may be present 3.4 virtual origin (of an impulse-voltage wave) O1point of intersection O1with the line of zero voltage of a line drawn through the points of 0,3 and 0,9 times the virtual peak value on the front of an impulse-voltage wave (see Figure 1) BS EN 60243-3:2014 6 60243-3 IEC:20

25、13 3.5 virtual front time (of an impulse-voltage wave) t1equal to 1,67 times the interval tfbetween the instants when the voltage is 0,3 and 0,9 times the peak value (tf, Figure 1) 3.6 virtual time to half-value t2time interval t2between the virtual origin O1and the instant on the tail when the volt

26、age has decreased to half the peak value 3.7 impulse breakdown voltage nominal peak voltage that the wave causing breakdown would have reached if breakdown had not occurred 3.8 withstand voltage highest nominal peak voltage of a set of three impulses which did not cause breakdown tft1t2t1,00,90,50,3

27、0O1t1= 1,67 tfBAU/UpIEC 1085/01Figure 1 Full impulse-voltage wave 4 Significance of the test In addition to the information of Clause 4 of IEC 60243-1:2013, the following points are of importance in connection with impulse-voltage tests. High-voltage equipment may be subjected to transient voltage s

28、tresses resulting from such causes as nearby lightning strokes. This is particularly true of apparatus such as transformers and switchgears used in electrical power transmission and distribution systems. The ability of insulating materials to withstand these transient voltages is important in establ

29、ishing the reliability of apparatus insulated with these materials. Transient voltages caused by lightning may be of either positive or negative polarity. In a symmetrical field between identical electrodes, the polarity has no effect on the electric BS EN 60243-3:201460243-3 IEC:2013 7 strength. Ho

30、wever, with dissimilar electrodes, there may be a pronounced polarity effect. When asymmetrical electrodes are used for testing materials with which the tester has no previous experience or knowledge, it is recommended that comparative tests be made with both directions of polarity. The standard wav

31、e shape is a 1,2/50 s wave, reaching peak voltage in approximately 1,2 s, and decaying to 50 % of peak value in approximately 50 s after the beginning of the wave. This wave is intended to simulate a lightning stroke that may strike a system without breakdown. NOTE If the object being tested has app

32、reciable inductive characteristics, it may be difficult or impossible to attain the specified wave shape with less than 5 % oscillations, as prescribed in 8.2. However, the procedures given in this standard are expected ordinarily to be applied to configurations of test specimens and electrodes whic

33、h are primarily capacitive. Testing of more complex configurations, such as between coils of completed apparatus or models of such apparatus, should be performed in accordance with the specifications for that apparatus. Because of the short time involved, dielectric heating, other thermal effects an

34、d the influence of injected space-charges may be reduced during impulse testing of most materials. Thus, impulse tests usually give higher values than the peak voltage of short-term ac tests. From comparisons of the impulse electric strength with the values drawn from longer time tests, inferences m

35、ay be drawn as to the modes of failure under the various tests for a given material. 5 Electrodes and test specimens Clause 5 of IEC 60243-1:2013 is applicable. 6 Conditioning before tests Clause 6 of IEC 60243-1:2013 is applicable. 7 Surrounding medium Clause 7 of IEC 60243-1:2013 is applicable. 8

36、Electrical apparatus 8.1 Voltage source The test voltage applied to the electrodes shall be provided by an impulse generator having the following characteristics. A choice of either positive or negative polarity shall be provided, one of the connections to the electrodes being earthed. Controls with

37、in the generator shall be capable of adjusting the shape of the wave applied to the test specimen under test to have a virtual front time t1of (1,2 0,36) s, and virtual time to half-value t2of (50 10) s (see Figure 1). The voltage capability and energy-storage capacity of the generator shall be suff

38、icient to apply impulse waves of the proper shape to any test specimens to be tested, up to the breakdown voltage or specified proof voltage of the material. The peak value of the voltage is taken as the virtual peak value, provided that the conditions of 8.2 are satisfied. BS EN 60243-3:2014 8 6024

39、3-3 IEC:2013 8.2 Voltage measurement Provisions shall be made for recording the voltage wave as applied to the test specimen, and for measuring the virtual peak voltage, the virtual front time and the virtual time to half-value within 5 % of the true values. If the voltage wave has oscillations with

40、 a magnitude of no more than 5 % of the peak value, and a frequency of at least 0,5 MHz, a mean curve may be drawn, the maximum amplitude of which is the virtual peak value. If the oscillations are of greater magnitude, or of lower frequency, the voltage wave is not acceptable for a standard test. 9

41、 Procedure Clause 9 of IEC 60243-1:2013 is applicable. However, the application of the voltage shall be as shown in Clause 10. 10 Application of voltage 10.1 Breakdown test Breakdown tests shall be in accordance with Clause 11 of IEC 60243-1:2013. The voltage impulses shall be applied in an increasi

42、ng series of sets of three waves of equal peak voltages. The peak voltage of the initial set should be approximately 70 % of the expected breakdown voltage. Increase the peak voltage of successive sets by 5 % to 10 % of the peak value of the first set. Table 1 of IEC 60243-1:2013 is applicable. Allo

43、w sufficient time between successive impulses for the generator to become completely charged. Normally, a time of three times the charging time constant for the generator is sufficient. Sufficient time shall also be allowed between successive impulses to allow dissipation of any injected space-charg

44、e. For many materials, the charging time of the generator will cover this eventuality. For materials having a longer space-charge retention time, the necessary time shall be specified in the material specification sheet. If this information is not known, but a long space-charge retention period is s

45、uspected, then additional tests should be run with longer intervals between impulses, to determine if a significant difference in breakdown values is obtained. A valid test on a test specimen is one in which impulse waves are applied at at least two voltage levels without breakdown, before breakdown

46、 occurs at the third or a subsequent level. The electric strength shall be based on the virtual peak voltage of the last set of three waves which was applied without breakdown. The breakdown voltage is the nominal voltage of the next set of waves causing breakdown. When using asymmetrical electrode

47、systems, preliminary tests shall be conducted to determine the polarity which yields the lower breakdown voltage. If significant differences are obtained, the polarity giving the lower test results should be used. 10.2 Proof tests One set of three impulses of specified proof voltage (virtual value)

48、shall be applied to the test specimen in accordance with Clause 11 of IEC 60243-1:2013. When necessary for calibration BS EN 60243-3:201460243-3 IEC:2013 9 purposes, up to three impulses with peak voltages not exceeding 80 % of the proof voltage may be applied prior to the application of the proof v

49、oltage waves. 11 Criterion of breakdown Clause 11 of IEC 60243-1:2013 is applicable. 12 Number of tests Clause 12 of IEC 60243-1:2013 is applicable. 13 Report Unless otherwise specified, the report shall include the following: a) a complete identification of the material tested, a description of the test specimens and the method of their preparation; b) the polarity of the impulse waves; c) the median (central value) of the electric strengths in kV/mm and/or of the breakdown voltages in kV (not