IEC_62979-2017.pdf

IEC 62979 Edition 1.0 2017-08 INTERNA TIONAL STA NDA RD Photov oltaic modules Bypass diode Thermal runaway test IEC 62979:2017-08(en)Copyright International Electrotechnical Commission THIS PUBLICA TION IS COPYRIGHT PROTECTED Copyright 2017 IEC,Geneva,Switzerland All rights reserved.Unless otherwise specified,no par t of this publication may be reproduced or utilized in any for m or by any means,electronic or mechanical,including photocopying and microfilm,without per mission in writing fr om either IEC or IECs member National Committee in the country of the requester.If you have any questions about IEC copyright or have an enquiry about obtaining additional r ights to this publication,please contact the address below or your local IEC member National Committee for further infor mation.IEC Centr al Office Tel.:+41 22 919 02 11 3,rue de Varemb Fax:+41 22 919 03 00 CH-1211 Geneva 20 infoiec.ch Switzerland www.iec.ch About t he IEC The International Electr otechnical Commission(IEC)is the leading global organization that prepar es and publishes Inter national Standards for all electr ical,electronic and related technologies.A bout IEC publications The technical content of IEC publications is kept under constant review by the IEC.Please make sur e that you have the latest edition,a cor rigenda or an amendment might have been published.IEC Cat alogue-webstore.iec.ch/cat alogue The stand-alone application for consulting the entire bibliographical information on IEC International Standards,Technical Specifications,Technical R eports and other documents.A v ailable for PC,Mac OS,A ndroid Tablets and iPad.IEC publications search-w w w.iec.ch/searchpub The adv anced search enables to find IEC publications by a variety of criteria(reference number,text,technical committee,).It also gives information on projec ts,replaced and withdrawn publications.IEC Just Published-webstore.iec.ch/justpublished Stay up to date on all new IEC publications.Just Published details all new publications released.A v ailable online and also once a month by email.Elect ropedia-w w w.elect ropedia.org The worlds leading online dic tionary of elec tronic and electrical terms containing 20 000 terms and definitions in English and French,with equiv alent terms in 16 additional languages.Also known as the International Electrotechnical Vocabulary (IEV)online.IEC Glossar y-st d.iec.ch/glossary 65 000 elec trotechnical terminology entries in English and French extracted from the Terms and Definitions clause of IEC publications issued since 2002.Some entries hav e been collected from earlier publications of IEC TC 37,77,86 and CISPR.IEC Customer Service Cent re-webstore.iec.ch/csc If y ou wish to giv e us y our feedback on this publication or need further assistance,please contact the Customer Serv ice Centre:csciec.ch.Copyright International Electrotechnical Commission IEC 62979 Edit ion 1.0 2017-08 INTER NA TIONAL STA NDA R D Photov oltaic modules By pass diode Thermal runaway test INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 27.160 ISBN 978-2-8322-4587-3 R egist er ed tr ademar k of t he Int er national Electr ot echnical Commission W arning!Make sure that y ou obtained this publication from an authorized distributor.Copyright International Electrotechnical Commission 2 IEC 62979:2017 IEC 2017 CONTENTS FOREWORD.3 INTRODUCTION.5 1 Scope.6 2 Normative references.6 3 Terms and definitions.6 4 Thermal runaway test.7 4.1 Diode thermal runaway.7 4.2 Test conditions.8 4.3 Preparation of test specimen.8 4.4 Test equipment.9 4.5 Test procedure.10 5 Pass or fail criteria.12 6 Test report.12 Figure 1 Illustration of how thermal runaway occurs.7 Figure 2 Circuit for measurement of Tlead and forward voltage.9 Figure 3 Circuit for flowing a forward current to the bypass diode.10 Figure 4 Circuit for applying a reverse bias voltage to the bypass diode.10 Figure 5 The typical pattern of thermal runaway.11 Figure 6 The pattern of non-thermal runaway.11 Copyright International Electrotechnical Commission IEC 62979:2017 IEC 2017 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ PHOTOVOLTAIC MODULES BYPASS DIODE THERMAL RUNAWAY TEST 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-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 preparatory work.International,governmental and non-governmental organizations liaising with the IEC also participate in this preparation.IEC collaborates