SIST EN IEC 61400-27-1:2020

Wind energy generation systems - Part 27-1: Electrical simulation models - Generic models (IEC 61400-27-1:2020)

IEC 61400-27-1:2020 defines standard electrical simulation models for wind turbines and wind power plants. The specified models are time domain positive sequence simulation models, intended to be used in power system and grid stability analyses. The models are applicable for dynamic simulations of short term stability in power systems. This document defines the generic terms and parameters for the electrical simulation models.
This document specifies electrical simulation models for the generic wind power plant topologies / configurations currently on the market. The wind power plant models include wind turbines, wind power plant control and auxiliary equipment. The wind power plant models are described in a modular way which can be applied for future wind power plant concepts and with different wind turbine concepts.

Windenergieanlagen - Teil 27-1: Elektrische Simulationsmodelle - Generische Modelle (IEC 61400-27-1:2020)

Systèmes de génération d’énergie éolienne - Partie 27-1: Modèles de simulation électrique - Modèles génériques (IEC 61400-27-1:2020)

IEC 61400-27-1:2020 définit des modèles de simulation électrique normalisés pour les éoliennes et les centrales éoliennes. Il s'agit de modèles de simulation directe dans le domaine temporel, destinés à être utilisés dans des analyses de stabilité du réseau d'énergie électrique et du réseau de distribution. Ces modèles s'appliquent à des simulations dynamiques de la stabilité à court terme des réseaux d'énergie électrique.
Le présent document définit les termes et paramètres génériques pour les modèles de simulation électrique.
Il spécifie des modèles de simulation électrique pour les topologies/configurations génériques de centrales éoliennes actuellement disponibles sur le marché. Les modèles de centrales éoliennes comprennent les éoliennes, la commande de centrale éolienne et les matériels auxiliaires. Les modèles de centrales éoliennes sont décrits de manière modulaire avec différents concepts d’éoliennes et peuvent être appliqués aux futurs concepts de centrales éoliennes.
Cette deuxième édition annule et remplace la première édition parue en 2015. Cette édition constitue une révision technique et une restructuration du contenu en deux parties. La nouvelle structure regroupe les modèles dans la partie 27-1 et les procédures de validation dans la partie 27-2.
Cette édition inclut les modifications techniques majeures suivantes par rapport à l’édition précédente:
a. "Éoliennes" a été modifié en "Modèles génériques" en raison de l’ajout de modèles de centrales éoliennes, et du transfert de la validation du modèle dans l’IEC 61400-27-2;
b. des modèles de centrales éoliennes ont été spécifiés, y compris la commande d’installation, le modèle de système de communication et la procédure d’agrégation pour le système de collecte de puissance, en plus des modèles d’éoliennes présentés dans l’édition précédente;
c. les procédures de validation des modèles d’éoliennes de la présente édition ont été transférées dans la partie 27-2;
d. la structure modulaire qui sépare la commande d’éolienne entre commande de pas et commande de l’aérogénérateur a été précisée, et les modules de mesure du réseau ont été extraits des modules de commande. Les figures ont été révisées en conséquence;
e. un modèle pour STATCOM a été ajouté;
f. des modules de composants électriques ont été ajoutés.

Sistemi za proizvodnjo energije na veter - 27-1. del: Električni simulacijski modeli - Splošni modeli (IEC 61400-27-1:2020)

General Information

• Status: Published
• Publication Date: 21-Sep-2020
• ICS: 21.180 - Housings, enclosures, other machine parts
• ICS: 27.180 - Wind turbine energy systems
• Technical Committee: IEHT - Electrotechnics - Hydraulic turbins
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 21-Sep-2020
• Due Date: 26-Nov-2020
• Completion Date: 22-Sep-2020
• Ref Project: EN IEC 61400-27-1:2020 - Wind energy generation systems - Part 27-1: Electrical simulation models - Generic models

Relations

• Replaces: SIST EN 61400-27-1:2015 - Wind turbines - Part 27-1: Electrical simulation models - Wind turbines
• Effective Date: 15-Sep-2020
• Revised: SIST EN 61400-27-1:2015 - Wind turbines - Part 27-1: Electrical simulation models - Wind turbines
• Effective Date: 18-Oct-2016

Overview

EN IEC 61400-27-1:2020 specifies standardized electrical simulation models for wind turbines and wind power plants. Published by CLC and identical to IEC 61400-27-1:2020, the standard defines time‑domain positive‑sequence models for use in power system and grid stability analyses, focusing on short‑term dynamic (stability) simulations. Models are given in a modular, generic form to represent current market wind power plant topologies and to accommodate future concepts.

Key topics and requirements

• Model scope and format
  • Time‑domain positive‑sequence simulation models for wind turbines, plant controls, and auxiliary equipment.
  • Formal, modular specification of model structures and blocks to ensure interoperable implementations.
• Wind turbine classifications
  • Generic module definitions for turbine generator/converter types (Type 1 through Type 4) and associated control modules.
• Functional modules
  • Aerodynamic, mechanical (e.g., two‑mass), generator/converter systems, pitch control, P/Q control, current limitation and grid‑interface modules.
• Wind power plant (WPP) models
  • Models for basic collection systems, WPP control and communication, reactive compensation, and auxiliary devices (e.g., STATCOM).
• Implementation and parameter guidance
  • Annexes include parameter estimation for collection systems, a two‑dimensional aerodynamic model, generator systems with external impedance, and a block symbol library for model building.
• Standards compliance
  • Normative references include relevant IEC publications (e.g., IEC 61970 series for CIM) and aligns with the IEC 61400 series.

Applications and who uses it

EN IEC 61400-27-1:2020 is used by:

• Power system planners and grid operators for dynamic stability and interconnection studies.
• Wind farm designers and OEMs to create validated, interoperable electrical models of turbines and plants.
• Simulation tool vendors and model developers implementing standard blocks and interfaces.
• Testing labs and researchers performing Hardware‑in‑the‑Loop (HIL) and control verification.
• Transmission system operators (TSOs) and regulators assessing grid‑code compliance and stability impact.

Practical applications include grid integration studies, short‑term stability analysis, control tuning, fault and protection simulations, and aggregation/parameter estimation of collection networks.

Related standards

• IEC 61400 family (wind energy generation systems)
• IEC 61970-301 / 61970-302 (Energy Management System - CIM and dynamics)
• IEC 60050-415 (Electrotechnical vocabulary - wind turbine generator systems)

Keywords: EN IEC 61400-27-1:2020, electrical simulation models, wind power plant models, time domain positive sequence, wind turbine models, grid stability analysis, modular wind plant models.

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2020
Nadomešča:
SIST EN 61400-27-1:2015
Sistemi za proizvodnjo energije na veter - 27-1. del: Električni simulacijski modeli -
Splošni modeli (IEC 61400-27-1:2020)
Wind energy generation systems - Part 27-1: Electrical simulation models - Generic
models (IEC 61400-27-1:2020)
Windenergieanlagen - Teil 27-1: Elektrische Simulationsmodelle - Generische Modelle
(IEC 61400-27-1:2020)
Systèmes de génération d’énergie éolienne - Partie 27-1: Modèles de simulation
électrique - Modèles génériques (IEC 61400-27-1:2020)
Ta slovenski standard je istoveten z: EN IEC 61400-27-1:2020
ICS:
27.180 Vetrne elektrarne Wind turbine energy systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 61400-27-1

NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2020
ICS 21.180 Supersedes EN 61400-27-1:2015 and all of its
amendments and corrigenda (if any)
English Version
Wind energy generation systems - Part 27-1: Electrical
simulation models - Generic models
(IEC 61400-27-1:2020)
Systèmes de génération d'énergie éolienne - Partie 27-1: Windenergieanlagen - Teil 27-1: Elektrische
Modèles de simulation électrique - Modèles génériques Simulationsmodelle - Generische Modelle
(IEC 61400-27-1:2020) (IEC 61400-27-1:2020)
This European Standard was approved by CENELEC on 2020-09-03. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61400-27-1:2020 E

European foreword
The text of document 88/762/FDIS, future edition 2 of IEC 61400-27-1, prepared by IEC/TC 88 "Wind
energy generation systems" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 61400-27-1:2020.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2021-06-03
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2023-09-03
document have to be withdrawn
This document supersedes EN 61400-27-1:2015 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice
The text of the International Standard IEC 61400-27-1:2020 was approved by CENELEC as a
European Standard without any modification.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1 Where an International Publication has been modified by common modifications, indicated by (mod), the
relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60050-415 1999 International Electrotechnical Vocabulary - - -
Part 415: Wind turbine generator systems
IEC 61970-301 - Energy management system application EN IEC 61970-301 -
program interface (EMS-API) - Part 301:
Common information model (CIM) base
IEC 61970-302 - Energy management system application EN IEC 61970-302 -
program interface (EMS-API) - Part 302:
Common information model (CIM)
dynamics
IEC 61400-27-1 ®
Edition 2.0 2020-07
INTERNATIONAL
STANDARD
Wind energy generation systems –

Part 27-1: Electrical simulation models – Generic models

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.180 ISBN 978-2-8322-8505-3

– 2 – IEC 61400-27-1:2020 © IEC 2020
CONTENTS
FOREWORD . 8
INTRODUCTION . 10
1 Scope . 12
2 Normative references . 12
3 Terms, definitions, abbreviations and subscripts . 12
3.1 Terms and definitions . 12
3.2 Abbreviations and subscripts . 16
3.2.1 Abbreviations . 16
3.2.2 Subscripts . 18
4 Symbols and units . 19
4.1 General . 19
4.2 Symbols (units) . 19
5 Functional specification of models . 23
5.1 General specifications . 23
5.2 Wind turbine models . 24
5.3 Wind power plant models . 25
6 Formal specification of modular structures of models . 25
6.1 General . 25
6.2 Wind turbine models . 26
6.2.1 General . 26
6.2.2 Type 1 . 26
6.2.3 Type 2 . 28
6.2.4 Type 3 . 30
6.2.5 Type 4 . 32
6.3 Auxiliary equipment models . 37
6.3.1 STATCOM . 37
6.3.2 Other auxiliary equipment . 38
6.4 Wind power plant models . 38
6.4.1 General . 38
6.4.2 Wind power plant control and communication . 39
6.4.3 Basic wind power plant . 40
6.4.4 Wind power plant with reactive power compensation . 41
7 Formal specification of modules . 42
7.1 General . 42
7.2 Aerodynamic modules . 43
7.2.1 Constant aerodynamic torque module . 43
7.2.2 One-dimensional aerodynamic module . 44
7.2.3 Two-dimensional aerodynamic module . 44
7.3 Mechanical modules . 46
7.3.1 Two mass module . 46
7.3.2 Other mechanical modules . 46
7.4 Generator and converter system modules . 46
7.4.1 Asynchronous generator module . 46
7.4.2 Type 3A generator system module . 47
7.4.3 Type 3B generator system module . 48
7.4.4 Type 4 generator system module . 49

IEC 61400-27-1:2020 © IEC 2020 – 3 –
7.4.5 Reference frame rotation module . 50
7.5 Electrical systems modules . 51
7.5.1 Electrical systems gamma module . 51
7.5.2 Other electrical systems modules . 52
7.6 Pitch control modules . 52
7.6.1 Pitch control power module . 52
7.6.2 Pitch angle control module. 53
7.7 Generator and converter control modules . 54
7.7.1 Rotor resistance control module . 54
7.7.2 P control module type 3 . 55
7.7.3 P control module type 4A . 58
7.7.4 P control module type 4B . 59
7.7.5 Q control module . 60
7.7.6 Current limitation module . 63
7.7.7 Constant Q limitation module . 64
7.7.8 QP and QU limitation module . 65
7.8 Grid interfacing modules . 66
7.8.1 Grid protection module . 66
7.8.2 Grid measurement module . 67
7.9 Wind power plant control modules. 68
7.9.1 WP P control module . 68
7.9.2 WP Q control module . 69
7.10 Communication modules . 71
7.10.1 General . 71
7.10.2 Communication delay module . 71
7.10.3 Linear communication module . 71
7.11 Electrical components modules . 72
7.11.1 Line module . 72
7.11.2 Transformer module . 72
7.11.3 Other electrical components modules . 72
Annex A (informative) Estimation of parameters for single branch power collection
system model. 73
A.1 General . 73
A.2 Description of method . 73
A.2.1 General . 73
A.2.2 Lines aggregation . 73
A.2.3 Wind turbine transformers aggregation . 74
A.3 Numerical example . 75
Annex B (informative) Two-dimensional aerodynamic model . 78
B.1 Objective . 78
B.2 Wind speed input model . 78
B.3 Parameters for power input module . 80
Annex C (informative) Implementation of generator systems modules with external

impedance . 81
Annex D (normative) Block symbol library . 84
D.1 General . 84
D.2 Switch . 84
D.3 Time step delay . 84
D.4 Stand-alone ramp rate limiter . 85

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D.5 First order filter . 85
D.6 Lookup table . 86
D.7 Comparator . 86
D.8 Timer . 87
D.9 Anti windup integrator . 88
D.10 Integrator with reset . 88
D.11 First order filter with limitation detection . 89
D.12 Rising edge detection . 89
D.13 Falling edge detection . 90
D.14 Delay flag . 90
D.15 Variable delay flag . 91
D.16 Dead band . 92
D.17 Circuit breaker . 92
Bibliography . 93

Figure 1 – Classification of power system stability according to IEEE/CIGRE Joint Task
Force on Stability Terms and Definitions [9] . 10
Figure 2 – Generic structure of WT models . 26
Figure 3 – Modular structure of the type 1A WT model . 27
Figure 4 – Modular structure of the type 1B WT model . 28
Figure 5 – Modular structure of the type 2 WT model . 29
Figure 6 – Modular structure of the type 3A and type 3B WT models . 30
Figure 7 – Modular generator control sub-structure of the type 3A and type 3B models. 31
Figure 8 – Modular structure of the type 4A WT model . 33
Figure 9 – Modular generator control sub-structure of the type 4A model . 34
Figure 10 – Modular structure of the type 4B WT model . 35
Figure 11 – Modular generator control sub-structure of the type 4B model . 36
Figure 12 – Modular structure of STATCOM model . 37
Figure 13 – Modular structure of the STATCOM control model . 37
Figure 14 – General structure of WP model . 38
Figure 15 – General modular structure of WP control and communication block . 39
Figure 16 – Single line diagram for basic WP model . 40
Figure 17 – Single line diagram for WP model with reactive power compensation . 41
Figure 18 – Block diagram for constant aerodynamic torque module . 44
Figure 19 – Block diagram for one-dimensional aerodynamic module . 44
Figure 20 – Block diagram for two-dimensional aerodynamic module . 45
Figure 21 – Block diagram for two mass module . 46
Figure 22 – Block diagram for type 3A generator system module . 47
Figure 23 – Block diagram for type 3B generator system module . 49
Figure 24 – Block diagram for type 4 generator system module . 50
Figure 25 – Block diagram for the reference frame rotation module . 51
Figure 26 – Single line diagram for electrical systems gamma module . 52
Figure 27 – Block diagram for pitch control power module . 53
Figure 28 – Block diagram for pitch angle control module . 54
Figure 29 – Block diagram for rotor resistance control module . 55

IEC 61400-27-1:2020 © IEC 2020 – 5 –
Figure 30 – Block diagram for type 3 P control module . 57
Figure 31 – Block diagram for type 3 torque PI . 58
Figure 32 – Block diagram for type 4A P control module . 59
Figure 33 – Block diagram for type 4B P control module . 60
Figure 34 – Block diagram for Q control module . 62
Figure 35 – Block diagram for current limiter . 64
Figure 36 – Block diagram for constant Q limitation module . 65
Figure 37 – Block diagram for QP and QU limitation module . 65
Figure 38 – Block diagram for grid protection system . 67
Figure 39 – Block diagram for u-f measurement . 68
Figure 40 – Block diagram for WP power/frequency control module . 69
Figure 41 – Block diagram for WP reactive power/voltage control module . 70
Figure 42 – Block diagram for communication delay module . 71
Figure 43 – Block diagram for linear communication module for an example with N
communication variables . 72
Figure A.1 – WP power collection system example . 75
Figure B.1 – Turbine aerodynamics model proposed by Fortmann (2014) . 78
Figure C.1 – Type 3A generator system module with parallel reactance . 81
Figure C.2 – Type 3B generator system module with parallel reactance . 82
Figure C.3 – Type 4 generator system module with parallel reactance . 83
Figure D.1 – Block symbol for switch with a) a variable flag input and b) a constant

mode . 84
Figure D.2 – Block symbol for single integration time step delay . 84
Figure D.3 – Block symbol for stand-alone ramp rate limiter . 85
Figure D.4 – Block diagram for implementation of the stand-alone ramp rate limiter . 85
Figure D.5 – Block symbol for first order filter with absolute limits, rate limits and
freeze flag . 85
Figure D.6 – Block diagram for implementation of the first order filter with absolute
limits, rate limits and freeze state. 86
Figure D.7 – Block diagram for implementation of the freeze state without filter (T = 0) . 86
Figure D.8 – Block symbol for lookup table . 86
Figure D.9 – Block symbols for comparators . 87
Figure D.10 – Block symbol for timer . 87
Figure D.11 – Function of timer . 87
Figure D.12 – Block symbol for anti windup integrator . 88
Figure D.13 – Block diagram for implementation of anti windup integrator . 88
Figure D.14 – Block symbol for integrator with reset . 88
Figure D.15 – Block symbol for first order filter with limitation detection . 89
Figure D.16 – Block diagram for implementation of first order filter with limitation

detection . 89
Figure D.17 – Block symbol rising edge detection . 89
Figure D.18 – Block diagram for rising edge detection . 90
Figure D.19 – Block symbol falling edge detection . 90
Figure D.20 – Block diagram for falling edge detection . 90
Figure D.21 – Block symbol for delay flag . 90

– 6 – IEC 61400-27-1:2020 © IEC 2020
Figure D.22 – Block diagram for implementation of delay flag . 91
Figure D.23 – Block symbol for delay flag . 91
Figure D.24 – Block diagram for implementation of variable delay flag . 92
Figure D.25 – Block symbol dead band . 92
Figure D.26 – Block symbol for circuit breaker . 92

Table 1 – Modules used in type 1A model . 27
Table 2 – Modules used in type 1B model . 28
Table 3 – Modules used in type 2 model . 29
Table 4 – Modules used in type 3A model . 31
Table 5 – Modules used in type 3B model . 32
Table 6 – Modules used in type 4A model . 34
Table 7 – Modules used in type 4B model . 36
Table 8 – Modules used in STATCOM model . 38
Table 9 – Modules used in WP control and communication model . 40
Table 10 – Models and additional modules used in the basic WP model . 41
Table 11 – Models and modules used in the WP model with reactive power
compensation . 42
Table 12 – Global model parameters . 42
Table 13 – Initialisation variable used in module block diagrams . 43
Table 14 – Parameter list for one-dimensional aerodynamic module . 44
Table 15 – Parameter list for two-dimensional aerodynamic module. 45
Table 16 – Parameter list for two-mass module . 46
Table 17 – Parameter list for type 3A generator system module . 47
Table 18 – Parameter list for type 3B generator system module . 48
Table 19 – Parameter list for type 4 generator system module . 50
Table 20 – Parameter list for reference frame rotation module . 50
Table 21 – Parameter list for electrical systems gamma module . 51
Table 22 – Parameter list for pitch control power module . 52
Table 23 – Parameter list for pitch angle control module . 53
Table 24 – Parameter list for rotor resistance control module . 54
Table 25 – Parameter list for P control module type 3 . 55
Table 26 – Parameter list for P control module type 4A . 58
Table 27 – Parameter list for P control module type 4B . 59
Table 28 – General WT Q control modes M . 60
qG
Table 29 – Reactive current injection for each FRT Q control modes M . 60
qFRT
Table 30 – Parameter list for Q control module . 61
Table 31 – Description of F flag values. 63
FRT
Table 32 – Parameter list for current limiter module . 63
Table 33 – Parameter list for constant Q limitation module . 64
Table 34 – Parameter list for QP and QU limitation module . 65
Table 35 – Parameter list for grid protection module . 66
Table 36 – Parameter list for grid measurement module . 67

IEC 61400-27-1:2020 © IEC 2020 – 7 –
Table 37 – Parameter list for power/frequency control module . 68
Table 38 – Parameter list for reactive power/voltage control module . 69
Table 39 – Parameter list for communication delay module . 71
Table 40 – Parameter list for linear communication module. 71
Table A.1 – Lines parameters and aggregation calculations. The data is in per-units
using WP base values . 76
Table A.2 – Transformers parameters . 76
Table A.3 – Estimated parameters for the single branch collection system model in
6.4.3 . 77
Table B.1 – Lookup table specifying the function ∂p (ν ) . 79
ω 0
Table B.2 – Parameter list for the wind speed input model . 79

– 8 – IEC 61400-27-1:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_____________
WIND ENERGY GENERATION SYSTEMS –

Part 27-1: Electrical simulation models –
Generic models
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
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Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61400-27-1 has been prepared by IEC technical committee 88: Wind
energy generation systems.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
The text of this International Standard is based on the following documents:
FDIS Report on voting
88/762/FDIS 88/771/RVD
Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

IEC 61400-27-1:2020 © IEC 2020 – 9 –
This second edition cancels and replaces the first edition, published in 2015. This edition
constitutes a technical revision and a restructure of the content into two parts. The new structure
joins the models in part 27-1 and the validation procedures in part 27-2.
This edition includes the following significant technical changes with respect to the previous
edition:
a) "Wind turbines" changed to "Generic models" because wind power plant models are also
included, and the model validation is moved to IEC 61400-27-2;
b) specification of models for wind power plants including plant control, communication system
model and aggregation procedure for power collection system in addition to the wind turbine
models in the previous edition;
c) moving validation prodedures for wind turbine models from this edition to part 27-2;
d) a more detailed modular structure separating wind turbine control into pitch control and
generator system control and extracting grid measurement modules from the control
modules. Figures are revised accordingly;
e) inclusion of model for STATCOM;
f) inclusion of electrical components modules.
A list of all parts in the IEC 61400, published under the general title Wind energy generation
systems, can be found on the IEC website.
Future standards in this series will carry the new general title as cited above. Titles of existing
standards in this series will be updated at the time of the next edition.
The committee has decided that the contents of this publication will remain unchanged until the
stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to
the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 10 – IEC 61400-27-1:2020 © IEC 2020
INTRODUCTION
IEC 61400-27-1 specifies standard dynamic electrical simulation models for wind turbines and
wind power plants. The specified wind turbine models can either be used in wind power plant
models or to represent wind turbines without wind power plant relationships. Apart from the
wind turbine models, the wind power plant model may include models for auxiliary equipment
such as STATCOMs which are often used in wind power plants.
The increasing penetration of wind energy in power systems implies that Transmission System
Operators (TSOs) and Distribution System Operators (DSOs) need to use dynamic models of
wind power generation for power system stability studies. The models developed by the wind
turbine manufacturers reproduce the behaviour of their machines with a high level of detail.
Such level of detail is not suitable for stability studies of large power systems with a huge
number of wind power plants, firstly because the high level of detail increases the complexity
and thus computer time dramatically, and secondly because the use of detailed manufacturer
specific models requires a substantial amount of input data to represent the individual wind
turbine types.
The purpose of this International Standard is to specify generic dynamic models, which can be
applied in power system stability studies. The IEEE/CIGRE Joint Task Force on Stability Terms
and Definitions [11] has classified power system stability in categories according to
Figure 1.
Figure 1 – Classification of power system stability according to IEEE/CIGRE Joint Task
Force on Stability Terms and Definitions [11]
Referring to these categories, the models are developed to represent wind power generation in
studies of large-disturbance short term stability phenomena, i.e. short term voltage stability,
short term frequency stability and short term transient stability studies referring to the definitions
of IEEE/CIGRE Joint Task Force on Stability Terms and Definitions in Figure 1. Thus, the
models are applicable for dynamic simulations of power system events such as short-circuits
(low voltage ride through), loss of generation or loads [12], and system separation of a
synchronous system into more synchronous areas.
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The numbers in square brackets refer to the Bibliography.

IEC 61400-27-1:2020 © IEC 2020 – 11 –
The models shall be complete enough to represent the dynamic behavior of the wind power
plant at the point of connection and of the wind turbine at the wind turbine terminals, but shall
also be suitable for large-scale grid studies. Therefore, simplified models are specified to
perform the typical response of known technologies.
The wind power plant models specified in this document are for fundamental frequency positive
sequence response .
The models have the following limitations:
– The models are not intended for long term stability analysis.
– The models are not intended for investigation of sub-synchronous interaction phenomena.
– The models are not intended for investigation of the fluctuations originating from wind speed
variability in time and space. This implies that the models do not include phenomena such
as turbulence, tower shadow, wind shear and wakes.
– The models do not cover phenomena such as harmonics, flicker or any other EMC emissions
included in the IEC 61000 series.
– The wind generation systems are highly non-linear and simplifications have been made in
the development of the models. Thus, linearisation for eigenvalue analysis is not trivial nor
necessarily appropriate based on these simplified models.
– This document does not address the specifics of short-circuit calculations.
– The models are not applicable to studies where wind turbines are islanded without
synchronous generation.
– The models are not intended for studies of situations with short-circuit ratios less than 3.
The short circuit limitation depends on wind turbine types, control modes and other settings.
The WT manufacturer can specify a lower limit for the applicable short-circuit ratio provided
that this application is validated according to part 27-2.
– The models are limited by the functi
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