SIST EN IEC 61400-12-3:2022

Wind energy generation systems - Part 12-3: Power performance - Measurement based site calibration (IEC 61400-12-3:2022)

This part of IEC 61400 specifies a measurement and analysis procedure for deriving the wind
speed correction due to terrain effects and applies to the performance testing of wind turbines
of all types and sizes connected to the electrical power network as described in IEC 61400-12-1.
The procedure applies to the performance evaluation of specific wind turbines at specific
locations.

Windenergieanlagen - Teil 12-3: Leistungsverhalten - Messbasierte Standortkalibrierung (IEC 61400-12-3:2022)

Systèmes de génération d’énergie éolienne - Partie 12-3: Performance de puissance - Étalonnage du site fondé sur le mesurage (IEC 61400-12-3:2022)

IEC 61400-12-3:2022 spécifie une procédure de mesure et d’analyse de dérivation de la correction de vitesse du vent en raison des effets de terrain, et s’applique aux essais de performance d’éoliennes raccordés au réseau électrique de tous types et de toutes tailles, comme cela est décrit dans l’IEC 61400-12-1. La procédure est applicable pour l’évaluation de la performance d'éoliennes spécifiques sur des sites spécifiques. La présente partie de l'IEC 61400 a pour objet de fournir une méthodologie uniforme qui garantit la cohérence, l’exactitude et la reproductibilité du mesurage et de l'analyse d’un étalonnage de site pour utilisation, afin de déterminer la performance de puissance des éoliennes. Le présent document fournit des recommandations relatives au mesurage, à l'analyse et à la consignation des rapports de l’étalonnage du site pour une utilisation ultérieure, dans les essais de performance de puissance des éoliennes.
La présente première édition de l’IEC 61400-12-3 fait partie d'une révision structurelle qui annule et remplace les normes de performance IEC 61400-12-1:2017 et IEC 61400-12-2:2013. Cette révision structurelle ne contient aucune modification technique par rapport à l'IEC 61400-12-1:2017 et l'IEC 61400-12 2:2013. Toutefois, les parties relatives aux mesurages du vent, au mesurage de l'étalonnage du site et à l'évaluation des obstacles et du terrain ont été extraites vers des normes distinctes.

Sistemi za proizvodnjo energije na veter - 12-3. del: Preskušanje zmogljivosti - Kalibracija mesta na podlagi meritev (IEC 61400-12-3:2022)

General Information

• Status: Published
• Publication Date: 23-Oct-2022
• ICS: 27.180 - Wind turbine energy systems
• Technical Committee: IEHT - Electrotechnics - Hydraulic turbins
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 13-Oct-2022
• Due Date: 18-Dec-2022
• Completion Date: 24-Oct-2022
• Ref Project: EN IEC 61400-12-3:2022 - Wind energy generation systems - Part 12-3: Power performance - Measurement based site calibration

Relations

• Revised: SIST EN 61400-12-1:2017/AC:2020 - Wind energy generation systems - Part 12-1: Power performance measurements of electricity producing wind turbines (IEC 61400-12-1:2017/COR2:2020)
• Effective Date: 29-Nov-2022
• Revised: SIST EN 61400-12-2:2013 - Wind turbines - Part 12-2: Power performance of electricity producing wind turbines based on nacelle anemometry
• Effective Date: 29-Nov-2022
• Revised: SIST EN 61400-12-1:2017 - Wind power generation systems - Part 12-1: Power performance measurement of electricity producing wind turbines (IEC 61400-12-1:2017)
• Effective Date: 29-Nov-2022
• Revised: SIST EN 61400-12-1:2017/AC:2021 - Wind energy generation systems - Part 12-1: Power performance measurement of electricity producing wind turbines (IEC 61400-12-1:2017/COR3:2021)
• Effective Date: 29-Nov-2022
• Revised: SIST EN 61400-12-1:2017/AC:2020 - Wind energy generation systems - Part 12-1: Power performance measurement of electricity producing wind turbines (IEC 61400-12-1:2017/COR1:2019)
• Effective Date: 29-Nov-2022
• Revised: SIST EN 61400-12-2:2013/AC:2016 - Wind turbines - Part 12-2: Power performance of electricity-producing wind turbines based on nacelle anemometry (IEC 61400-12-2:2013/COR1:2016)
• Effective Date: 29-Nov-2022

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN IEC 61400-12-3:2022
01-december-2022
Sistemi za proizvodnjo energije na veter - 12-3. del: Preskušanje zmogljivosti -
Kalibracija mesta na podlagi meritev (IEC 61400-12-3:2022)
Wind energy generation systems - Part 12-3: Power performance - Measurement based
site calibration (IEC 61400-12-3:2022)
Windenergieanlagen - Teil 12-3: Leistungsverhalten - Messbasierte Standortkalibrierung
(IEC 61400-12-3:2022)
Systèmes de génération d’énergie éolienne - Partie 12-3: Performance de puissance -
Étalonnage du site fondé sur le mesurage (IEC 61400-12-3:2022)
Ta slovenski standard je istoveten z: EN IEC 61400-12-3:2022
ICS:
27.180 Vetrne elektrarne Wind turbine energy systems
SIST EN IEC 61400-12-3:2022 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 61400-12-3:2022


EUROPEAN STANDARD EN IEC 61400-12-3

NORME EUROPÉENNE

EUROPÄISCHE NORM October 2022
ICS 27.180

English Version
Wind energy generation systems - Part 12-3: Power
performance - Measurement based site calibration
(IEC 61400-12-3:2022)
Systèmes de génération d'énergie éolienne - Partie 12-3: Windenergieanlagen - Teil 12-3: Leistungsverhalten -
Performance de puissance - Étalonnage du site fondé sur le Messbasierte Standortkalibrierung
mesurage (IEC 61400-12-3:2022)
(IEC 61400-12-3:2022)
This European Standard was approved by CENELEC on 2022-10-03. 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,
Türkiye 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
© 2022 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 61400-12-3:2022 E

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SIST EN IEC 61400-12-3:2022
EN IEC 61400-12-3:2022 (E)
European foreword
The text of document 88/824/CDV, future edition 1 of IEC 61400-12-3, prepared by IEC/TC 88 "Wind
energy generation systems" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 61400-12-3:2022.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2023-07-03
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2025-10-03
document have to be withdrawn

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.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 61400-12-3:2022 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
IEC 61400-50 NOTE Harmonized as EN IEC 61400-50
2

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SIST EN IEC 61400-12-3:2022
EN IEC 61400-12-3:2022 (E)
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 61400-12-1 - Wind energy generation systems - Part 12- EN IEC 61400-12-1 -
1: Power performance measurement of
electricity producing wind turbines
IEC 61400-12-5 - Wind energy generation systems - Part 12- EN IEC 61400-12-5 -
5: Power performance - Assessment of
obstacles and terrain
1
IEC 61400-50-1 - Wind energy generation systems - Part 50- EN IEC 61400-50-1 -
1: Wind Measurement - Application of
Meteorological Mast, Nacelle and Spinner
Mounted Instruments
ISO/IEC Guide 98-3 2008 Uncertainty of measurement - Part 3: - -
Guide to the expression of uncertainty in
measurement (GUM:1995)


1
Under preparation. Stage at time of publication: FprEN IEC 61400-50-1:2022.
3

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SIST EN IEC 61400-12-3:2022




IEC 61400-12-3

®


Edition 1.0 2022-08




INTERNATIONAL



STANDARD




NORME


INTERNATIONALE
colour

inside










Wind energy generation systems –

Part 12-3: Power performance – Measurement based site calibration



Systèmes de génération d'énergie éolienne –

Partie 12-3: Performance de puissance – Étalonnage du site fondé sur le

mesurage















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 27.180 ISBN 978-2-8322-5596-4




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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SIST EN IEC 61400-12-3:2022
– 2 – IEC 61400-12-3:2022 © IEC 2022
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 8
4 Symbols, units and abbreviated terms . 10
5 General . 12
6 Overview of the procedure . 13
7 Test set-up . 14
7.1 Considerations for selection of the test wind turbine and location of the
meteorological mast . 14
7.1.1 General . 14
7.1.2 Type A: . 14
7.1.3 Type B: . 14
7.1.4 Type C:. 15
7.2 Instrumentation . 15
8 Data acquisition and rejection criteria . 16
9 Analysis . 17
9.1 General . 17
9.2 Assessment of site shear conditions . 17
9.2.1 Shear calculations and characterisation plots . 17
9.2.2 Assess significance of shear . 17
9.2.3 Establish correlation of shear between locations . 18
9.3 Method 1: Bins of wind direction and wind shear . 19
9.4 Method 2: Linear regression method where wind shear is not a significant
influence . 19
9.5 Additional calculations . 20
10 Site calibration uncertainty . 21
10.1 Site calibration category A uncertainty . 21
10.1.1 Site calibration K-fold analysis . 21
10.1.2 Site calibration statistical uncertainty for each fold. 22
10.2 Site calibration category B uncertainty . 23
10.2.1 General . 23
10.2.2 Anemometer – Pre-calibration . 23
10.2.3 Anemometer – Post-calibration . 23
10.2.4 Anemometer – Classification . 23
10.2.5 Anemometer – Mounting . 24
10.2.6 Anemometer – Data acquisition . 24
10.2.7 Anemometer – Lightning finial. 25
10.3 Combining uncertainties in the wind speed measurement from flow distortion
due to site calibration u . 25
VT,i
10.4 Combined uncertainty . 26
11 Quality checks and additional uncertainties . 26
11.1 Convergence check . 26
11.2 Correlation check for linear regression (see 9.4) . 26
11.3 Change in correction between adjacent wind direction bins . 26

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11.3.1 General . 26
11.3.2 Removal of the wind direction sensor between site calibration and
power performance test . 27
11.4 Site calibration and power performance measurements in different seasons . 28
Annex A (informative) Verification of results . 29
Annex B (informative) Site calibration examples . 31
B.1 Example A . 31
B.1.1 Site description: . 31
B.1.2 Site calibration setup: . 31
B.1.3 Site calibration evaluation: . 31
B.1.4 Step 1: Check the significance of wind shear at the site according to
9.2.2: . 31
B.1.5 Step 2: Verify correlation of wind shear at wind turbine and reference

meteorological mast locations – Example A . 32
B.1.6 Step 3: Calculate results according to 9.2.3 . 33
B.1.7 Step 4: Quality checks and additional uncertainties . 33
B.2 Example B . 35
B.2.1 Site description: . 35
B.2.2 Site calibration setup: . 35
B.2.3 Step 1: Check the significance of wind shear at the site:. 36
B.2.4 Step 2A: Verify correlation of wind shear at wind turbine and reference
meteorological mast locations, example B . 36
B.2.5 Step 2B: Attempt to remove non-correlating wind shear data . 38
B.2.6 Step 3: Calculate results . 39
B.2.7 Step 4: Additional uncertainties: . 39
B.3 Example C . 41
B.3.1 Site description: . 41
B.3.2 Site calibration setup: . 41
B.3.3 Step 1: Check the significance of wind shear at the site:. 42
B.3.4 Step 2: Verify correlation of wind shear at wind turbine and reference
meteorological mast locations, example C . 42
B.3.5 Step 3: Calculate results . 42
B.3.6 Step 4: Quality checks and uncertainty . 42
B.3.7 Anemometer operational uncertainty: . 42
B.3.8 Convergence check: . 42
B.3.9 Change in magnitude of correction between bins: . 43
B.3.10 Wind vane adjustment: . 43
B.3.11 Seasonal uncertainty adjustment: . 43
Bibliography . 44

Figure 1 – Site calibration flow chart . 13
Figure 2 – Terrain types . 15
Figure A.1 – Example of the results of a verification test . 30
Figure B.1 – Wind shear exponent vs. time of day, Example A . 32
Figure B.2 – Wind shear exponents at wind turbine location vs. reference
meteorological mast, example A where the colour axis = wind speed (m/s) . 32
Figure B.3 – Wind speed ratios and number of data points vs. wind shear exponent
and wind direction bin – wind speed ratios (full lines), number of data points (dotted
lines) . 33

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Figure B.4 – Data convergence check for 190° bin . 35
Figure B.5 – Wind shear exponent vs. time of day, example B . 36
Figure B.6 – Wind shear exponents at wind turbine location vs. reference
meteorological mast, example B . 36
Figure B.7 – Linear regression of wind turbine location vs. reference meteorological

mast hub height wind speeds for 330° bin . 37
Figure B.8 – Wind speed ratios vs. wind speed for the 330° bin . 37
Figure B.9 – Wind speed ratios vs. wind shear for the 330° bin . 38
Figure B.10 – Wind shear exponents at wind turbine location vs. reference
meteorological mast post-filtering . 38
Figure B.11 – Linear regression of wind turbine location vs. reference meteorological
mast hub height wind speeds for 330° bin, post-filtering . 39
Figure B.12 – Wind speed ratios vs. wind speed for the 330° bin, post-filtering . 39
Figure B.13 – Data convergence check for 330° bin . 40
Figure B.14 – Site calibration wind shear vs. power curve test wind shear . 41
Figure B.15 – Convergence check for 270° bin . 43

Table B.1 – Site calibration flow corrections (wind speed ratio) . 34
Table B.2 – Site calibration data count . 34
2
Table B.3 – r values for each wind direction bin . 40
Table B.4 – Additional uncertainty due to change in bins for example B . 40
Table B.5 – Additional uncertainty due to change in bins for example C . 43

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SIST EN IEC 61400-12-3:2022
IEC 61400-12-3:2022 © IEC 2022 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

WIND ENERGY GENERATION SYSTEMS –

Part 12-3: Power performance –
Measurement based site calibration

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
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interested IEC National Committees.
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6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
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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.
IEC 61400-12-3 has been prepared by IEC technical committee 88: Wind energy generation
systems. It is an International Standard.
This first edition of IEC 61400-12-3 is part of a structural revision that cancels and replaces the
performance standards IEC 61400-12-1:2017 and IEC 61400-12-2:2013. The structural revision
contains no technical changes with respect to IEC 61400-12-1:2017 and IEC 61400-12-2:2013,
but the parts that relate to wind measurements, measurement of site calibration and assessment
of obstacle and terrain have been extracted into separate standards.
The purpose of the re-structure was to allow the future management and revision of the power
performance standards to be carried out more efficiently in terms of time and cost and to provide
a more logical division of the wind measurement requirements into a series of separate
standards which could be referred to by other use case standards in the IEC 61400 series and
subsequently maintained and developed by appropriate experts.

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– 6 – IEC 61400-12-3:2022 © IEC 2022
The text of this International Standard is based on the following documents:
Draft Report on voting
88/824/CDV 88/869/RVC

Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
A list of all parts in the IEC 61400 series, published under the general title Wind energy
generation systems, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.

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SIST EN IEC 61400-12-3:2022
IEC 61400-12-3:2022 © IEC 2022 – 7 –
INTRODUCTION
The purpose of this part of IEC 61400 is to provide a uniform methodology that will ensure
consistency, accuracy and reproducibility in the measurement and analysis of a site calibration
for use in the determination of the power performance of wind turbines. This document has
been prepared with the anticipation that it would be applied by:
a) a wind turbine manufacturer striving to meet well-defined power performance requirements
and/or a possible declaration system;
b) a wind turbine purchaser in specifying such performance requirements;
c) a wind turbine operator who may be required to verify that stated, or required, power
performance specifications are met for new or refurbished units;
d) a wind turbine planner or regulator who will need to be able to accurately and fairly define
power performance characteristics of wind turbines in response to regulations or permit
requirements for new or modified installations.
This document provides guidance in the measurement, analysis, and reporting of the site
calibration for subsequent use in power performance testing for wind turbines. This document
will benefit those parties involved in the manufacture, installation planning and permitting,
operation, utilization, and regulation of wind turbines. The technically accurate measurement
and analysis techniques recommended in this document should be applied by all parties to
ensure that continuing development and operation of wind turbines is carried out in an
atmosphere of consistent and accurate communication relative to wind turbine performance.
This document presents measurement and reporting procedures expected to provide accurate
results that can be replicated by others. Meanwhile, a user of this document should be aware
of differences that arise from large variations in wind shear and turbulence. Therefore, a user
should consider the influence of these differences and the data selection criteria in relation to
the purpose of the test before contracting the power performance measurements.
The committee recognizes that the restructuring of the IEC 61400-12 series represents a
significant increase in complexity and perhaps greater difficulty to implement. However, it
represents the committee’s best attempt to address issues introduced by larger wind turbines
operating in significant wind shear and complex terrain. The committee recommends that the
new techniques introduced be validated immediately by test laboratories through inter-lab
proficiency testing. The committee recommends a Maintenance Cycle Report be written within
three years of the publication of this document which includes recommendations, clarifications
and simplifications that will improve the practical implementation of this document. If necessary
a revision should be proposed at the same time to incorporate these recommendations,
clarifications and simplifications.

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WIND ENERGY GENERATION SYSTEMS –

Part 12-3: Power performance –
Measurement based site calibration



1 Scope
This part of IEC 61400 specifies a measurement and analysis procedure for deriving the wind
speed correction due to terrain effects and applies to t
...