IEC 61400-1:2019

Wind energy generation systems - Part 1: Design requirements

IEC 61400-1:2019 specifies essential design requirements to ensure the structural integrity of wind turbines. Its purpose is to provide an appropriate level of protection against damage from all hazards during the planned lifetime. This document is concerned with all subsystems of wind turbines such as control and protection functions, internal electrical systems, mechanical systems and support structures. This document applies to wind turbines of all sizes. For small wind turbines, IEC 61400-2 can be applied. IEC 61400-3-1 provides additional requirements to offshore wind turbine installations. This document is intended to be used together with the appropriate IEC and ISO standards mentioned in Clause 2. This edition includes the following significant technical changes with respect to the previous edition:
a) general update and clarification of references and requirements;
b) extension of wind turbine classes to allow for tropical cyclones and high turbulence;
c) Weibull distribution of turbulence standard deviation for normal turbulence model (NTM);
d) updated design load cases (DLCs), in particular DLC 2.1 and 2.2;
e) revision of partial safety factor specifications
The contents of the corrigendum of September 2019 have been included in this copy.

Systèmes de génération d'énergie éolienne - Partie 1: Exigences de conception

l'IEC 61400-1:2019 spécifie les exigences de conception essentielles pour assurer l’intégrité structurelle des éoliennes. Elle a pour objet de fournir un niveau de protection approprié contre les dommages causés par tous les dangers pendant la durée de vie prévue. Le présent document concerne tous les sous-systèmes des éoliennes tels que les fonctions de commande et de protection, les systèmes électriques internes, les systèmes mécaniques et les structures de support. Le présent document s'applique aux éoliennes de toutes dimensions. Pour les petites éoliennes, l'IEC 61400-2 peut s’appliquer. L'IEC 61400-3-1 donne les exigences supplémentaires relatives aux installations d'éoliennes en pleine mer. Le présent document est destiné à être utilisé avec les normes IEC et ISO appropriées mentionnées à l’Article  REF _Ref34379257 \r \h 2 08D0C9EA79F9BACE118C8200AA004BA90B02000000080000000D0000005F00520065006600330034003300370039003200350037000000 . Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a. mise à jour générale et clarification des références et des exigences;
b. extension des classes d'éoliennes pour les adapter aux cyclones tropicaux et aux fortes turbulences;
c. loi de Weibull de l'écart type de la turbulence pour le modèle de turbulence normale (NTM);
d. cas de charge pour la conception (DLC) mis à jour, en particulier les DLC 2.1 et 2.2;
e. révision des spécifications du facteur de sécurité partielle

General Information

• Status: Published
• Publication Date: 07-Feb-2019
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 27.180 - Wind turbine energy systems
• ICS: 31.220 - Electromechanical components for electronic and telecommunications equipment
• Technical Committee: TC 88 - Wind energy generation systems
• Drafting Committee: MT 1 - TC 88/MT 1
• Current Stage: PPUB - Publication issued
• Start Date: 09-Nov-2018
• Completion Date: 08-Feb-2019

Relations

• Corrected By: IEC 61400-1:2019/COR1:2019 - Corrigendum 1 - Wind energy generation systems - Part 1: Design requirements
• Effective Date: 05-Sep-2023
• Revises: IEC 61400-1:2005/AMD1:2010 - Amendment 1 - Wind turbines - Part 1: Design requirements
• Effective Date: 05-Sep-2023
• Revises: IEC 61400-1:2005 - Wind turbines - Part 1: Design requirements
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61400-1 ®
Edition 4.0 2019-02
INTERNATIONAL
STANDARD
colour
inside
Wind energy generation systems –
Part 1: Design requirements
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
your local IEC member National Committee for further information.

IEC Central Office Tel.: [phone]
3, rue de Varembé [e-mail]
CH-1211 Geneva 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.

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IEC 61400-1 ®
Edition 4.0 2019-02
INTERNATIONAL
STANDARD
colour
inside
Wind energy generation systems –

Part 1: Design requirements
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.180 ISBN 978-2-8322-6253-5

– 2 – IEC 61400-1:2019 © IEC 2019
CONTENTS
FOREWORD . 10
INTRODUCTION . 12
1 Scope . 13
2 Normative references . 13
3 Terms and definitions . 15
4 Symbols and abbreviated terms . 23
4.1 Symbols and units. 23
4.2 Abbreviated terms . 26
5 Principal elements . 27
5.1 General . 27
5.2 Design methods . 27
5.3 Safety classes . 27
5.4 Quality assurance . 27
5.5 Wind turbine markings . 27
6 External conditions . 28
6.1 General . 28
6.2 Wind turbine classes . 28
6.3 Wind conditions . 30
6.3.1 General . 30
6.3.2 Normal wind conditions . 31
6.3.3 Extreme wind conditions . 33
6.4 Other environmental conditions . 38
6.4.1 General . 38
6.4.2 Normal other environmental conditions . 39
6.4.3 Extreme other environmental conditions . 39
6.5 Electrical power network conditions . 39
7 Structural design . 40
7.1 General . 40
7.2 Design methodology . 40
7.3 Loads. 40
7.3.1 General . 40
7.3.2 Gravitational and inertial loads . 41
7.3.3 Aerodynamic loads . 41
7.3.4 Actuation loads . 41
7.3.5 Other loads . 41
7.4 Design situations and load cases . 41
7.4.1 General . 41
7.4.2 Power production (DLC 1.1 to 1.5) . 44
7.4.3 Power production plus occurrence of fault or loss of electrical network
connection (DLC 2.1 to 2.5) . 45
7.4.4 Start-up (DLC 3.1 to 3.3) . 47
7.4.5 Normal shutdown (DLC 4.1 to 4.2) . 47
7.4.6 Emergency stop (DLC 5.1) . 48
7.4.7 Parked (standstill or idling) (DLC 6.1 to 6.4) . 48
7.4.8 Parked plus fault conditions (DLC 7.1) . 49
7.4.9 Transport, assembly, maintenance and repair (DLC 8.1 and 8.2) . 49

7.5 Load calculations . 49
7.6 Ultimate limit state analysis. 50
7.6.1 Method . 50
7.6.2 Ultimate strength analysis . 53
7.6.3 Fatigue failure . 56
7.6.4 Stability . 57
7.6.5 Critical deflection analysis . 57
7.6.6 Special partial safety factors . 58
8 Control system . 58
8.1 General . 58
8.2 Control functions . 58
8.3 Protection functions . 59
8.4 Control system failure analysis . 59
8.4.1 General . 59
8.4.2 Independence and common-cause failures . 60
8.4.3 Fault exclusions . 60
8.4.4 Failure mode return periods . 60
8.4.5 Systematic failures . 60
8.5 Manual operation . 60
8.6 Emergency stop button function . 60
8.7 Manual, automatic, and remote restart . 61
8.8 Braking system . 62
9 Mechanical systems . 62
9.1 General . 62
9.2 Errors of fitting . 63
9.3 Hydraulic or pneumatic systems . 63
9.4 Main gearbox . 63
9.5 Yaw system . 63
9.6 Pitch system . 64
9.7 Protection function mechanical brakes . 64
9.8 Rolling element bearings . 64
9.8.1 General . 64
9.8.2 Main shaft bearings . 64
9.8.3 Generator bearings . 64
9.8.4 Pitch and yaw bearings . 65
10 Electrical system . 65
10.1 General . 65
10.2 General requirements for the electrical system . 65
10.3 Internal environmental conditions . 65
10.4 Protective devices . 67
10.5 Disconnection from supply sources . 67
10.6 Earth system . 67
10.7 Lightning protection . 67
10.8 Electrical cables . 68
10.9 Self-excitation . 68
10.10 Protection against lightning electromagnetic impulse . 68
10.11 Power quality . 68
10.12 Electromagnetic compatibil
...

IEC 61400-1 ®
Edition 4.0 2019-02
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Wind turbines energy generation systems –
Part 1: Design requirements
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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International Standards for all electrical, electronic and related technologies.

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latest edition, a corrigendum or an amendment might have been published.

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and withdrawn publications. Also known as the International Electrotechnical Vocabulary

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IEC 61400-1 ®
Edition 4.0 2019-02
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Wind turbines energy generation systems –

Part 1: Design requirements
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.180 ISBN 978-2-8322-6571-0

– 2 – IEC 61400-1:2019 RLV © IEC 2019
CONTENTS
FOREWORD . 10
INTRODUCTION . 13
1 Scope . 14
2 Normative references . 14
3 Terms and definitions . 16
4 Symbols and abbreviated terms . 25
4.1 Symbols and units. 25
4.2 Abbreviated terms . 28
5 Principal elements . 29
5.1 General . 29
5.2 Design methods . 29
5.3 Safety classes . 29
5.4 Quality assurance . 29
5.5 Wind turbine markings . 29
6 External conditions . 30
6.1 General . 30
6.2 Wind turbine classes . 30
6.3 Wind conditions . 32
6.3.1 General . 32
6.3.2 Normal wind conditions . 34
6.3.3 Extreme wind conditions . 36
6.4 Other environmental conditions . 41
6.4.1 General . 41
6.4.2 Normal other environmental conditions . 42
6.4.3 Extreme other environmental conditions . 42
6.5 Electrical power network conditions . 42
7 Structural design . 43
7.1 General . 43
7.2 Design methodology . 43
7.3 Loads. 43
7.3.1 General . 43
7.3.2 Gravitational and inertial loads . 44
7.3.3 Aerodynamic loads . 44
7.3.4 Actuation loads . 44
7.3.5 Other loads . 44
7.4 Design situations and load cases . 44
7.4.1 General . 44
7.4.2 Power production (DLC 1.1 to 1.5) . 47
7.4.3 Power production plus occurrence of fault or loss of electrical network
connection (DLC 2.1 to 2.4 2.5) . 48
7.4.4 Start-up (DLC 3.1 to 3.3) . 50
7.4.5 Normal shutdown (DLC 4.1 to 4.2) . 50
7.4.6 Emergency shutdown stop (DLC 5.1) . 51
7.4.7 Parked (standstill or idling) (DLC 6.1 to 6.4) . 51
7.4.8 Parked plus fault conditions (DLC 7.1) . 52
7.4.9 Transport, assembly, maintenance and repair (DLC 8.1 and 8.2) . 52

7.5 Load calculations . 53
7.6 Ultimate limit state analysis. 54
7.6.1 Method . 54
7.6.2 Ultimate strength analysis . 56
7.6.3 Fatigue failure . 60
7.6.4 Stability . 61
7.6.5 Critical deflection analysis . 61
7.6.6 Special partial safety factors . 62
8 Control and protection system . 63
8.1 General . 63
8.2 Control functions . 63
8.3 Protection functions . 64
8.4 Control system failure analysis . 65
8.4.1 General . 65
8.4.2 Independence and common-cause failures . 65
8.4.3 Fault exclusions . 66
8.4.4 Failure mode return periods . 66
8.4.5 Systematic failures . 66
8.5 Manual operation . 66
8.6 Emergency stop button function . 66
8.7 Manual, automatic, and remote restart . 67
8.8 Braking system . 68
9 Mechanical systems . 68
9.1 General . 68
9.2 Errors of fitting . 69
9.3 Hydraulic or pneumatic systems . 69
9.4 Main gearbox . 69
9.5 Yaw system . 69
9.6 Pitch system . 70
9.7 Protection function mechanical brakes . 70
9.8 Rolling element bearings . 71
9.8.1 General . 71
9.8.2 Main shaft bearings . 71
9.8.3 Generator bearings . 71
9.8.4 Pitch and yaw bearings . 71
10 Electrical system . 72
10.1 General . 72
10.2 General requirements for the electrical system . 72
10.3 Internal environmental conditions . 72
10.4 Protective devices . 74
10.5 Disconnection devices from supply sources . 74
10.6 Earth system . 74
10.7 Lightning protection . 75
10.8 Electrical cables . 75
10.9 Self-excitation . 75
10.10 Protection against lightning electromagnetic impulse . 76
10.11 Power quality . 76
10.12 Electromagnetic compatibility . 76
10.13 Power electronic converter systems and equipment . 76
...

IEC 61400-1 ®
Edition 4.0 2019-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Wind energy generation systems –
Part 1: Design requirements
Systèmes de génération d'énergie éolienne –
Partie 1: Exigences de conception

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
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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.

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The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
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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

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IEC publications issued since 2002. Some entries have been
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IEC 61400-1 ®
Edition 4.0 2019-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Wind energy generation systems –

Part 1: Design requirements
Systèmes de génération d'énergie éolienne –

Partie 1: Exigences de conception

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 27.180 ISBN 978-2-8322-7972-4

– 2 – IEC 61400-1:2019 © IEC 2019
CONTENTS
FOREWORD . 10
INTRODUCTION . 12
1 Scope . 13
2 Normative references . 13
3 Terms and definitions . 15
4 Symbols and abbreviated terms . 23
4.1 Symbols and units. 23
4.2 Abbreviated terms . 26
5 Principal elements . 27
5.1 General . 27
5.2 Design methods . 27
5.3 Safety classes . 27
5.4 Quality assurance . 27
5.5 Wind turbine markings . 28
6 External conditions . 28
6.1 General . 28
6.2 Wind turbine classes . 29
6.3 Wind conditions . 30
6.3.1 General . 30
6.3.2 Normal wind conditions . 31
6.3.3 Extreme wind conditions . 33
6.4 Other environmental conditions . 38
6.4.1 General . 38
6.4.2 Normal other environmental conditions . 39
6.4.3 Extreme other environmental conditions . 39
6.5 Electrical power network conditions . 40
7 Structural design . 40
7.1 General . 40
7.2 Design methodology . 41
7.3 Loads. 41
7.3.1 General . 41
7.3.2 Gravitational and inertial loads . 41
7.3.3 Aerodynamic loads . 41
7.3.4 Actuation loads . 41
7.3.5 Other loads . 42
7.4 Design situations and load cases . 42
7.4.1 General . 42
7.4.2 Power production (DLC 1.1 to 1.5) . 44
7.4.3 Power production plus occurrence of fault or loss of electrical network
connection (DLC 2.1 to 2.5) . 45
7.4.4 Start-up (DLC 3.1 to 3.3) . 47
7.4.5 Normal shutdown (DLC 4.1 to 4.2) . 47
7.4.6 Emergency stop (DLC 5.1) . 48
7.4.7 Parked (standstill or idling) (DLC 6.1 to 6.4) . 48
7.4.8 Parked plus fault conditions (DLC 7.1) . 49
7.4.9 Transport, assembly, maintenance and repair (DLC 8.1 and 8.2) . 49

7.5 Load calculations . 49
7.6 Ultimate limit state analysis. 50
7.6.1 Method . 50
7.6.2 Ultimate strength analysis . 53
7.6.3 Fatigue failure . 56
7.6.4 Stability . 57
7.6.5 Critical deflection analysis . 57
7.6.6 Special partial safety factors . 58
8 Control system . 58
8.1 General . 58
8.2 Control functions . 58
8.3 Protection functions . 59
8.4 Control system failure analysis . 59
8.4.1 General . 59
8.4.2 Independence and common-cause failures . 60
8.4.3 Fault exclusions . 60
8.4.4 Failure mode return periods . 60
8.4.5 Systematic failures . 60
8.5 Manual operation . 60
8.6 Emergency stop button function . 60
8.7 Manual, automatic, and remote restart . 61
8.8 Braking system . 62
9 Mechanical systems . 62
9.1 General . 62
9.2 Errors of fitting . 63
9.3 Hydraulic or pneumatic systems . 63
9.4 Main gearbox .
...