IEC IEC 61400-24 Edition 2.02019-07 INTERNATIONAL STANDARD colour inside Wind energy generation systems - Part 24: Lightning protection IEC 61400-24:2019-07(en) nal Electrotechnical Commissior by IHS Mark license from IHS THIS PUBLICATION IS COPYRIGHTPROTECTED Copyright @ 2019 IEC, Geneva, Switzerland either IEC or IEC's 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, piease 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 Varembé [email protected] CH-1211Geneva 20 www.iec.ch Switzerland 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 latestedition,a corrigendumoranamendmentmighthavebeenpublished. IECpublicationssearch-webstore.iec.ch/advsearchform Electropedia -www.electropedia.org The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology, variety of criteria (reference number, text,technical containing more than 22 000 terminoiogical entries in English committee,..). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages. and withdrawn publications. Also known as the International Electrotechnical Vocabulary (IEV) online. IECJustPublished-webstore.iec.ch/justpublished Stayuptodateonall newIECpublications.JustPublished IECGlossary-std.iec.ch/glossary details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and once a month by email. French extracted from the Terms and Definitions clause of iEC publications issued since 2002. Some entries have been IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and If you wish to give us your feedback on this publication or CISPR. need further assistance, please contact the Customer Service Centre: [email protected]. Copyright International Electrotechnical Commission vided by IHS Markit under license with IEC ense from IHS Not for Resale, 07/07/2019 16:35:31 MDT JEC IEC 61400-24 Edition 2.02019-07 INTERNATIONAL STANDARD colour inside Windenergygenerationsystems- Part 24: Lightning protection INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 27.180 ISBN 978-2-8322-6599-4 Warning! Make sure that you obtained this publication from an authorized distributor. ? Registered trademark of the International Electrotechnical Commission tional Electrotechnical Commission ense from IHS Not for Resale, 07/07/2019 16:35:31 MDT - 2 - IEC 61400-24:2019 @ IEC 2019 CONTENTS FOREWORD 11 1 Scope. .13 2 Normative references .13 3 Terms and definitions .15 4 Symbols and units . .21 5 Abbreviated terms . 6 Lightning environment for wind turbine . ..25 6.1 General.. ..25 6.2 Lightning current parameters and lightning protection levels (LPL). .25 Lightning exposure assessment.. .26 7.1 General.. ..26 7.2 Assessing the frequency of lightning affecting a single wind turbine or a group of wind turbines.... ..28 7.2.1 Categorization of lightning events ..28 7.2.2 Estimation of average number of lightning flashes to a single or a group of wind turbines.. ...28 7.2.3 Estimation of average annual number of lightning flashes near the wind turbine (NM) . .31 7.2.4 Estimation of average annual number of lightning flashes tothe service lines connecting the wind turbines (NL) ..... ...32 7.2.5 Estimation of average annual number of lightning flashes near the service lines connecting the wind turbine (Nj) ... .32 7.3 Assessing the risk of damage .. .33 7.3.1 Basic equation... ..33 7.3.2 Assessmen