IEC 61400-24:2019

Wind energy generation systems - Part 24: Lightning protection

IEC 61400-24:2019 applies to lightning protection of wind turbine generators and wind power systems. Refer to guidelines for small wind turbines in annex.
This document defines the lightning environment for wind turbines and risk assessment for wind turbines in that environment. It defines requirements for protection of blades, other structural components and electrical and control systems against both direct and indirect effects of lightning. Test methods to validate compliance are included.
Guidance on the use of applicable lightning protection, industrial electrical and EMC standards including earthing is provided.
This second edition cancels and replaces the first edition, published in 2010. This edition includes the following significant technical changes with respect to the previous edition:
a) it is restructured with a main normative part, while informative information is placed in annexes.

Systèmes de génération d’énergie éolienne - Partie 24: Protection contre la foudre

l’IEC 61400-24:2019 s’applique à la protection des aérogénérateurs et des parcs éoliens contre la foudre. Se reporter à l’Annexe M pour les lignes directrices applicables aux éoliennes de petite taille.Le présent document définit l’environnement de foudre applicable aux éoliennes et l’appréciation du risque pour ces mêmes éoliennes dans cet environnement. Il définit les exigences concernant la protection des pales, des autres composants structurels, ainsi que des réseaux de puissance et de commande contre les effets directs et indirects de la foudre. Les méthodes d’essai pour validation de la conformité sont incluses dans le présent document.Des recommandations relatives à l’utilisation des normes applicables en matière de protection contre la foudre, ainsi que des normes électriques industrielles et de CEM, y compris la mise à la terre sont fournies.
Cette deuxième édition annule et remplace la première édition parue en 2010. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) sa restructuration comprend une partie normative principale, les informations informatives étant intégrées dans des annexes.

General Information

• Status: Published
• Publication Date: 02-Jul-2019
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 27.180 - Wind turbine energy systems
• ICS: 29.060.10 - Wires
• Technical Committee: TC 88 - Wind energy generation systems
• Drafting Committee: MT 24 - TC 88/MT 24
• Current Stage: PPUB - Publication issued
• Start Date: 22-Mar-2019
• Completion Date: 03-Jul-2019

Relations

• Revises: IEC 61400-24:2010 - Wind turbines - Part 24: Lightning protection
• Effective Date: 05-Sep-2023
• Revises: IEC TR 61400-24:2002 - Wind turbine generator systems - Part 24: Lightning protection
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61400-24 ®
Edition 2.0 2019-07
INTERNATIONAL
STANDARD
colour
inside
Wind energy generation systems –
Part 24: Lightning protection
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 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, please contact the address below or
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About the IEC
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International Standards for all electrical, electronic and related technologies.

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IEC 61400-24 ®
Edition 2.0 2019-07
INTERNATIONAL
STANDARD
colour
inside
Wind energy generation systems –

Part 24: Lightning protection
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.180 ISBN 978-2-8322-6599-4

– 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 . 24
6 Lightning environment for wind turbine . 25
6.1 General . 25
6.2 Lightning current parameters and lightning protection levels (LPL) . 25
7 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 (N ) . 31
M
7.2.4 Estimation of average annual number of lightning flashes to the service
lines connecting the wind turbines (N ) . 32
L
7.2.5 Estimation of average annual number of lightning flashes near the
service lines connecting the wind turbine (N ) . 32
I
7.3 Assessing the risk of damage . 33
7.3.1 Basic equation . 33
7.3.2 Assessment of risk components due to flashes to the wind turbine (S1) . 34
7.3.3 Assessment of the risk component due to flashes near the wind turbine
(S2) . 34
7.3.4 Assessment of risk components due to flashes to a service line
connected to the wind turbine (S3) . 35
7.3.5 Assessment of risk component due to flashes near a service line
connected to the wind turbine (S4) . 35
8 Lightning protection of subcomponents . 36
8.1 General . 36
8.1.1 Lightning protection level (LPL) . 36
8.1.2 Lightning protection zones (LPZ) . 37
8.2 Blades . 37
8.2.1 General . 37
8.2.2 Requirements . 37
8.2.3 Verification . 38
8.2.4 Protection design considerations . 38
8.2.5 Test methods . 41
8.3 Nacelle and other structural components . 42
8.3.1 General . 42
8.3.2 Hub . 42
8.3.3 Spinner . 42
8.3.4 Nacelle . 43
8.3.5 Tower . 43
8.3.6 Verification methods . 44

8.4 Mechanical drive train and yaw system . 44
8.4.1 General . 44
8.4.2 Bearings . 44
8.4.3 Hydraulic systems . 45
8.4.4 Spark gaps and sliding contacts . 46
8.4.5 Verification . 46
8.5 Electrical low-voltage systems and electronic systems and installations . 46
8.5.1 General . 46
8.5.2 Equipotential bonding within the wind turbine . 50
8.5.3 LEMP protection and immunity levels . 51
8.5.4 Shielding and line routing . 52
8.5.5 SPD protection . 53
8.5.6 Testing methods for system immunity tests . 57
8.6 Electrical high-voltage (HV) power systems . 57
9 Earthing of wind turbines . 59
9.1 General . 59
9.1.1 Purpose and scope . 59
9.1.2 Basic requirements . 59
9.1.3 Earth electrode arrangements . 59
9.1.4 Earthing system impedance . 60
9.2 Equipotential bonding . 60
9.2.1 General . 60
9.2.2 Lightning equipotential bonding for metal installations . 60
9.3 Structural components . 61
9.3.1 General . 61
9.3.2 Metal tubular type tower . 61
9.3.3 Metal reinforced concrete towers . 61
9.3.4 Lattice tower . 61
9.3.5 Systems inside the tower . 62
9.3.6 Concrete foundation . 62
9.3.7 Rocky area foundation . 62
9.3.8 Metal mono-pile foundation . 63
9.3.9 Offshore foundation . 63
9.4 Electrode shape dimensions . 63
9.5 Execution and maintenance of the earthing system . 64
10 Personal safety . 64
11 Documentation of lightning protection system . 66
11.1 General . 66
11.2 Documentation necessary during assessment for design evaluation. 66
11.2.1 General . 66
11.2.2 General documentation . 66
11.2.3 Documentation for rotor blades . 66
11.2.4 Documentation of mechanical systems . 67
11.2.5 Documentation of electrical and electronic systems . 67
11.2.6 Documentation of earthing and bonding systems . 67
11.2.7 Documentation of nacelle cover, hub and tower lightning protection
systems . 67
11.3 Site-specific information . 68
11.4 Documentation to be provided in the manuals for LPS inspections . 68

– 4 – IEC 61400-24:2019 © IEC 2019
11.5 Manuals . 68
12 Inspection of lightning protection system . 68
12.1 Scope of inspection . 68
12.2 Order of inspections .
...

IEC 61400-24 ®
Edition 2.0 2019-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Wind energy generation systems –
Part 24: Lightning protection
Systèmes de génération d’énergie éolienne –
Partie 24: Protection contre la foudre

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
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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.

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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 corrigendum or an amendment might have been published.

IEC publications search - 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 terminological 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.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
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once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
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IEC 61400-24 ®
Edition 2.0 2019-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Wind energy generation systems –

Part 24: Lightning protection
Systèmes de génération d’énergie éolienne –

Partie 24: Protection contre la foudre

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 27.180 ISBN 978-2-8322-8688-3

– 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 . 24
6 Lightning environment for wind turbine . 25
6.1 General . 25
6.2 Lightning current parameters and lightning protection levels (LPL) . 25
7 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 (N ) . 31
M
7.2.4 Estimation of average annual number of lightning flashes to the service
lines connecting the wind turbines (N ) . 31
L
7.2.5 Estimation of average annual number of lightning flashes near the
service lines connecting the wind turbine (N ) . 32
I
7.3 Assessing the risk of damage . 33
7.3.1 Basic equation . 33
7.3.2 Assessment of risk components due to flashes to the wind turbine (S1) . 34
7.3.3 Assessment of the risk component due to flashes near the wind turbine
(S2) . 34
7.3.4 Assessment of risk components due to flashes to a service line
connected to the wind turbine (S3) . 35
7.3.5 Assessment of risk component due to flashes near a service line
connected to the wind turbine (S4) . 35
8 Lightning protection of subcomponents . 36
8.1 General . 36
8.1.1 Lightning protection level (LPL) . 36
8.1.2 Lightning protection zones (LPZ) . 37
8.2 Blades . 37
8.2.1 General . 37
8.2.2 Requirements . 37
8.2.3 Verification . 38
8.2.4 Protection design considerations . 38
8.2.5 Test methods . 41
8.3 Nacelle and other structural components . 42
8.3.1 General . 42
8.3.2 Hub . 42
8.3.3 Spinner . 42
8.3.4 Nacelle . 43
8.3.5 Tower . 43
8.3.6 Verification methods . 44

8.4 Mechanical drive train and yaw system . 44
8.4.1 General . 44
8.4.2 Bearings . 44
8.4.3 Hydraulic systems . 45
8.4.4 Spark gaps and sliding contacts . 46
8.4.5 Verification . 46
8.5 Electrical low-voltage systems and electronic systems and installations . 47
8.5.1 General . 47
8.5.2 Equipotential bonding within the wind turbine . 51
8.5.3 LEMP protection and immunity levels . 52
8.5.4 Shielding and line routing . 53
8.5.5 SPD protection . 54
8.5.6 Testing methods for system immunity tests . 58
8.6 Electrical high-voltage (HV) power systems . 58
9 Earthing of wind turbines . 60
9.1 General . 60
9.1.1 Purpose and scope . 60
9.1.2 Basic requirements . 60
9.1.3 Earth electrode arrangements . 60
9.1.4 Earthing system impedance . 61
9.2 Equipotential bonding . 61
9.2.1 General . 61
9.2.2 Lightning equipotential bonding for metal installations . 61
9.3 Structural components . 62
9.3.1 General . 62
9.3.2 Metal tubular type tower . 62
9.3.3 Metal reinforced concrete towers . 62
9.3.4 Lattice tower . 62
9.3.5 Systems inside the tower . 63
9.3.6
...