IEC_TS_60815-4-2016.pdf

IEC TS 60815-4 Edition 1.0 2016-10 TECHNICAL SPECIFICATION Selection and dimensioning of high-voltage insulators intended for use in polluted conditions Part 4:Insulators for d.c.systems IEC T S 60815-4:2016-10(en)colourinside THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2016 IEC,Geneva,Switzerland All rights reserved.Unless otherwise specified,no part of this publication may be reproduced or utilized in any form or by any means,electronic or mechanical,including photocopying and microfilm,without permission in writing from 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 rights to this publication,please contact the address below or your local IEC member National Committee for further information.IEC Central 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 the IEC The International Electrotechnical Commission(IEC)is the leading global organization that prepares and publishes International Standards for all electrical,electronic and related technologies.About IEC publications The technical content of IEC publications is kept under constant review by the IEC.Please make sure that you have the latest edition,a corrigenda or an amendment might have been published.IEC Catalogue-webstore.iec.ch/catalogue The stand-alone applica tion for consulting the entire bibliogr aphical informa tion on IEC International Standar ds,Technical Specifica tions,Technical Reports and other documents.Av ailable for PC,Mac OS,Android Tablets and iPad.IEC publications search-www.iec.ch/searchpub The adv anced sear ch enables to find IEC publications by a var iety of cr iter ia(refer ence number,text,technica l committee,).It also gives infor ma tion on pr ojects,replaced and w ithdraw n publications.IEC Just Published-webstore.iec.ch/justpublished Stay up to da te on all new IEC publications.Just Published details all new publica tions released.Av ailable online and also once a month by email.Electropedia-www.electropedia.org The w or lds leading online dictionary of electronic and electrical terms containing 20 000 terms and definitions in English and Fr ench,w ith equiv alent terms in 15 additional languages.Also know n as the Inter national Electr otechnical Vocabulary(IEV)online.IEC Glossary-std.iec.ch/glossary 65 000 electrotechnical terminology entries in English and Fr ench extracted fr om the Terms and Definitions clause of IEC publica tions issued since 2002.Some entr ies hav e been collected from ear lier publications of IEC TC 37,77,86 and CISPR.IEC Customer Serv ice Centre-webstore.iec.ch/csc If you w ish to giv e us your feedback on this publication or need fur ther assistance,plea se contact the Customer Ser v ice Centre:csciec.ch.IEC TS 60815-4 Edition 1.0 2016-10 TECHNICAL SPECIFICATION Selection and dimensioning of high-voltage insulators intended for use in polluted conditions Part 4:Insulators for d.c.systems INT ERNAT IONAL ELECT ROT ECHNICAL COMMISSION ICS 29.080.10 ISBN 978-2-8322-3704-5 Registered t rademark of the Internat ional Electrotechnica l Commission Warning!Mak e sure that you obtained this publication from an authorized distributor.colourinside 2 IEC TS 60815-4:2016 IEC 2016 CONTENTS FOREWORD.4 INTRODUCTION.6 1 Scope.7 2 Normative references.7 3 Terms,definitions and abbreviated terms.8 3.1 Terms and definitions.8 3.2 Abbreviated terms.9 4 Principles.9 4.1 General.9 4.2 Overall design process.10 5 Materials.11 6 Site severity determination.12 6.1 Input data.12 6.2 d.c.pollution accumulation correction:Kp.12 6.3 Chemical composition of the pollution layer(Type A pollution).13 6.4 Correcting for NSDD(Type A pollution).13 6.5 Correcting for CUR(Type A pollution,cap and pin insulators).14 6.6 Effect of diameter on the pollution accumulation Kd.14 6.7 Correction for the number of similar insulators in parallel:Ks.14 7 Determination of the reference d.c.site severity.15 8 Determination of the reference d.c.USCD.16 9 Correction of the RUSCD for each candidate insulator.17 9.1 Correction for the effect of diameter on pollution withstand performance Cd.17 9.2 Correction for altitude Ca.18 9.3 Determination of the required USCD for each candidate.18 10 Checking the profile parameters.19 10.1 General.19 10.2 Alternating sheds defined by shed overhang.19 10.3 Spacing versus shed overhang.20 10.4 Minimum distance between sheds.20 10.5 Creepage distance versus clearance.21 10.6 Shed angle.22 10.7 Creepage factor.22 11 Design verification.23 11.1 General.23 11.2 Operating experience.23 11.3 Laboratory testing.23 Annex A(informative)Hydrophobicity transfer materials.24 A.1 Qualitative flashover behaviour.24 Annex B(informative)Dependence of USCD on pollution severity.26 B.1 Pollution type A.26 B.2 Pollution Type B.28 Bibliographic References.29 IEC TS 60815-4:2016 IEC 2016 3 Figure 1 Overall design process for d.c.insu