1、 IEC/TS 61251Edition 2.0 2008-05TECHNICAL SPECIFICATION Electrical insulating materials A.C.voltage endurance evaluation Introduction IEC/TS 61251:2008(E)LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.THIS PUBLICATION IS COPYRIGHT PRO
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9、ed.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.IEC/TS 61251Edition 2.0 2008-05TECHNICAL SPECIFICATION Electrical insulating materials A.C.voltage endurance evaluation Introduction INTERNATIONAL ELECTROTECHNICAL COMMISSION RICS 29.035.01;17.220.99 PRICE CODE
10、ISBN 2-8318-9777-7LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.2 TS 61251 IEC:2008(E)CONTENTS FOREWORD.3 1 Scope and object.5 2 Normative references.5 3 Terms and definitions.5 4 Voltage endurance.7 4.1 Voltage endurance testing.7 4
11、.2 Electrical stress.7 4.3 Voltage endurance(VE)graph.7 4.4 Short-time electric strength.8 4.5 Voltage endurance coefficient(VEC)n.8 4.6 Differential VEC(nd).8 4.7 Electrical threshold stress(Et).9 4.8 Voltage endurance relationship.9 5 Test methods.10 5.1 Introductory remark.10 5.2 Tests at constan
12、t stress.11 5.2.1 Conventional VE test.11 5.2.2 Diagnostic measurements.11 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.14 5.6 Suggested test method.14 6 Evaluation of
13、 voltage endurance.15 6.1 Significance of the VEC.15 6.2 Significance of the electrical threshold stress.15 6.3 Dispersion of data and precision requirements.15 6.4 Presentation of the results.16 Annex A(informative)The Weibull distribution.17 Bibliography.19 Figure 1 General voltage endurance line.
14、8 Figure 2 Determination of the differential VEC nd at a generic point P of the VE line.9 Figure 3 Plotting the VE line with progressive stress.13 LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.TS 61251 IEC:2008(E)3 INTERNATIONAL ELEC
15、TROTECHNICAL COMMISSION _ ELECTRICAL INSULATING MATERIALS A.C.VOLTAGE ENDURANCE EVALUATION INTRODUCTION FOREWORD 1)The International Electrotechnical Commission(IEC)is a worldwide organization for standardization comprising all national electrotechnical committees(IEC National Committees).The object
16、 of IEC is to promote international co-operation 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“IEC Publication(s)”).Their preparation is entrusted to technical committees;any IEC National Committee interested in the subject dealt with may participate in this
