EN 61400-11:2003

SLOVENSKI SIST EN 61400-11:2003

STANDARD
oktober 2003
Sistemi generatorjev vetrne turbine – 11. del: Tehnike merjenja hrupa (IEC
61400-11:2002)
Wind turbine generator systems - Part 11: Acoustic noise measurement techniques
ICS 17.140.20; 27.180 Referenčna številka
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

EUROPEAN STANDARD EN 61400-11
NORME EUROPÉENNE
EUROPÄISCHE NORM May 2003
ICS 27.180 Supersedes EN 61400-11:1998

English version
Wind turbine generator systems
Part 11: Acoustic noise measurement techniques
(IEC 61400-11:2002)
Aérogénérateurs Windenergieanlagen
Partie 11: Techniques de mesure Teil 11: Schallmessverfahren
du bruit acoustique (IEC 61400-11:2002)
(CEI 61400-11:2002)
This European Standard was approved by CENELEC on 2003-03-18. 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 Central Secretariat 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 Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta,
Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2003 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 61400-11:2003 E
Foreword
The text of document 88/166/FDIS, future edition 2 of IEC 61400-11, prepared by IEC TC 88, Wind
turbines, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as
EN 61400-11 on 2003-03-18.
This European Standard supersedes EN 61400-11:1998.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2003-12-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) -

Annexes designated "normative" are part of the body of the standard.
Annexes designated "informative" are given for information only.
In this standard, annex ZA is normative and annexes A to D are informative.
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 61400-11:2002 was approved by CENELEC as a European
Standard without any modification.
__________
- 3 - EN 61400-11:2003
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of any
of these publications apply to this European Standard only when incorporated in it by amendment or
revision. For undated references the latest edition of the publication referred to applies (including
amendments).
NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
Publication Year Title EN/HD Year
IEC 60386 1972 Method of measurement of speed - -
fluctuations in sound recording and
reproducing equipment
IEC 60651 1979 Sound level meters EN 60651 1994

IEC 60688 1992 Electrical measuring transducers for EN 60688 1992
converting a.c. electrical quantities to
analogue or digital signals
IEC 60804 2000 Integrating-averaging sound level EN 60804 2000
meters
1)
IEC 60942 1997 Electroacoustics - Sound calibrators EN 60942 1998

IEC 61260 1995 Electroacoustics - Octave-band and EN 61260 1995
fractional-octave-band filters

IEC 61400-12 1998 Wind turbine generator systems EN 61400-12 1998
Part 12: Wind turbine power
performance testing
1)
EN 60942 is superseded by EN 60942:2003, which is based on IEC 60942:2003.

INTERNATIONAL IEC
STANDARD
61400-11
Second edition
2002-12
Wind turbine generator systems –
Part 11:
Acoustic noise measurement techniques
Aérogénérateurs –
Partie 11:
Techniques de mesure du bruit acoustique
 IEC 2002  Copyright - all rights reserved
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 the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch  Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale
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International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – 61400-11  IEC:2002(E)
CONTENTS
FOREWORD . 4
INTRODUCTION .5
1 Scope . 6
2 Normative references. 6
3 Definitions . 7
4 Symbols and units . 8
5 Outline of method . 9
6 Instrumentation.10
6.1 Acoustic instruments.10
6.2 Non-acoustic Instruments .11
6.3 Traceable calibration .12
7 Measurements and measurement procedures .12
7.1 Measurement positions.12
7.2 Acoustic measurements.13
7.3 Non-acoustic measurements.15
8 Data reduction procedures.17
8.1 Wind speed .17
8.2 Correction for background noise .18
8.3 Apparent sound power levels.18
8.4 One-third octave band levels .19
8.5 Tonality .19
8.6 Directivity (optional).22
9 Information to be reported.23
9.1 Characterisation of the wind turbine.23
9.2 Physical environment.24
9.3 Instrumentation.24
9.4 Acoustic data.24
9.5 Non-acoustic data.25
9.6 Uncertainty .25
Annex A (informative) Other possible characteristics of wind turbine noise emission
and their quantification.35
Annex B (informative) Criteria for recording/playback equipment.37
Annex C (Informative) Assessment of turbulence intensity .39
Annex D (informative) Assessment of measurement uncertainty.40
Bibliography.43
Figure 1 – Mounting of the microphone .26
Figure 2 − Picture of microphone and board .27
Figure 3 − Standard pattern for microphone measurement positions (plan view).28
Figure 4 − Illustration of the definitions of R and slant distance R .29
0 1
61400-11  IEC:2002(E) – 3 –
Figure 5 − Allowable region for meteorological mast position as a function of β –
plan view.30
Figure 6 − Allowable range for anemometer height – cross section .31
Figure 7 – Workflow chart for tonality procedure .32
Figure 8 – Illustration of L level in the critical band .33
70 %
Figure 9 – Illustration of lines below the L + 6dB criterion .33
70 %
Figure 10 – Illustration of L level and lines classified as masking.34
pn,avg
Figure 11 – Illustration of classifying all spectral lines .34
Figure B.1 − Tolerances for frequency characteristic, IEC 60651 type 1 .37
Table 1 − Roughness length.18
Table 2 − Frequency resolution .19
Table D.1 − Examples of possible values of type B uncertainty components relevant for
apparent sound power level .41

– 4 – 61400-11  IEC:2002(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
WIND TURBINE GENERATOR SYSTEMS –
Part 11: Acoustic noise measurement techniques
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of the IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, the IEC publishes International Standards. Their preparation is
entrusted to technical committees; any IEC National Committee interested in the subject dealt with may
participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. The IEC collaborates closely with the International
Organization for Standardization (ISO) in accordance with conditions determined by agreement between the
two organizations.
2) The formal decisions or agreements of the 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 National Committees.
3) The documents produced have the form of recommendations for international use and are published in the form
of standards, technical specifications, technical reports or guides and they are accepted by the National
Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
5) The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
6) Attention is drawn to the possibility that some of the elements of this International Standard may be the subject
of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61400-11 has been prepared by IEC technical committee 88: Wind
turbine systems.
This second edition of IEC 61400-11 cancels and replaces the first edition published in 1998
and constitutes a technical revision.
The text of thi
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