IEC 61400-11:2012/AMD1:2018
(Amendment)Amendment 1 - Wind turbines - Part 11: Acoustic noise measurement techniques
Amendment 1 - Wind turbines - Part 11: Acoustic noise measurement techniques
The contents of the corrigendum of October 2019 have been included in this copy.
Amendement 1 - Éoliennes - Partie 11: Techniques de mesure du bruit acoustique
Le contenu du corrigendum d'octobre 2019 a été pris en considération dans cet exemplaire.
General Information
Relations
Standards Content (Sample)
IEC 61400-11 ®
Edition 3.0 2018-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
A MENDMENT 1
AM ENDEMENT 1
Wind turbines –
Part 11: Acoustic noise measurement techniques
Éoliennes –
Partie 11: Techniques de mesure du bruit acoustique
IEC 61400-11:2012-11/AMD1:2018-06(en-fr)
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.
Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des
questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez
les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.
IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
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.
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 corrigenda or an amendment might have been published.
IEC Catalogue - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
The stand-alone application for consulting the entire The world's leading online dictionary of electronic and
bibliographical information on IEC International Standards, electrical terms containing 21 000 terms and definitions in
Technical Specifications, Technical Reports and other English and French, with equivalent terms in 16 additional
documents. Available for PC, Mac OS, Android Tablets and languages. Also known as the International Electrotechnical
iPad. Vocabulary (IEV) online.
IEC publications search - webstore.iec.ch/advsearchform IEC Glossary - std.iec.ch/glossary
The advanced search enables to find IEC publications by a 67 000 electrotechnical terminology entries in English and
variety of criteria (reference number, text, technical French extracted from the Terms and Definitions clause of
committee,…). It also gives information on projects, replaced IEC publications issued since 2002. Some entries have been
and withdrawn publications. collected from earlier publications of IEC TC 37, 77, 86 and
CISPR.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Customer Service Centre - webstore.iec.ch/csc
details all new publications released. Available online and If you wish to give us your feedback on this publication or
also once a month by email. need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC
La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des
Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.
A propos des publications IEC
Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la
plus récente, un corrigendum ou amendement peut avoir été publié.
Catalogue IEC - webstore.iec.ch/catalogue Electropedia - www.electropedia.org
Application autonome pour consulter tous les renseignements
Le premier dictionnaire en ligne de termes électroniques et
bibliographiques sur les Normes internationales,
électriques. Il contient 21 000 termes et définitions en anglais
Spécifications techniques, Rapports techniques et autres
et en français, ainsi que les termes équivalents dans 16
documents de l'IEC. Disponible pour PC, Mac OS, tablettes
langues additionnelles. Egalement appelé Vocabulaire
Android et iPad.
Electrotechnique International (IEV) en ligne.
Recherche de publications IEC -
Glossaire IEC - std.iec.ch/glossary
webstore.iec.ch/advsearchform
67 000 entrées terminologiques électrotechniques, en anglais
La recherche avancée permet de trouver des publications IEC et en français, extraites des articles Termes et Définitions des
en utilisant différents critères (numéro de référence, texte, publications IEC parues depuis 2002. Plus certaines entrées
comité d’études,…). Elle donne aussi des informations sur les antérieures extraites des publications des CE 37, 77, 86 et
projets et les publications remplacées ou retirées. CISPR de l'IEC.
IEC Just Published - webstore.iec.ch/justpublished Service Clients - webstore.iec.ch/csc
Restez informé sur les nouvelles publications IEC. Just Si vous désirez nous donner des commentaires sur cette
Published détaille les nouvelles publications parues. publication ou si vous avez des questions contactez-nous:
Disponible en ligne et aussi une fois par mois par email. sales@iec.ch.
IEC 61400-11 ®
Edition 3.0 2018-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
A MENDMENT 1
AM ENDEMENT 1
Wind turbines –
Part 11: Acoustic noise measurement techniques
Éoliennes –
Partie 11: Techniques de mesure du bruit acoustique
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 27.180 ISBN 978-2-8322-5760-9
– 2 – IEC 61400-11:2012/AMD1:2018
© IEC 2018
FOREWORD
This amendment has been prepared IEC technical committee 88: Wind energy generation
systems.
The text of this amendment is based on the following documents:
CDV Report on voting
88/615/CDV 88/644A/RVC
Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this amendment and the base publication will
remain unchanged until the stability date indicated on the IEC website 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.
The contents of the corrigendum of October 2019 have been included in this copy.
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.
_____________
INTRODUCTION to the Amendment
This amendment to IEC 61400-11:2012 addresses the situation where a measurement
consists of measurements series on different days or with substantially different conditions.
Furthermore, clarifications have been introduced on tonality analysis and reporting. Editorial
changes have been made.
6 Instrumentation
6.1.2 Equipment for the determination of the equivalent continuous A-weighted
sound pressure level
Add "relevant to this document" after "requirements".
6.1.3 Equipment for the determination of A-weighted 1/3-octave band spectra
Add, in the second sentence, "relevant to this document" after "requirements".
© IEC 2018
7 Acoustic measurements and measurement procedures
7.1 Acoustic measurement positions
Add, at the end of the second paragraph after 2 %, the following new text:
The measurement distance shall be as close as possible to R . The allowed tolerance should
only be used where it is essential to obtain valid data and, where this is done, clear evidence
shall be reported to justify the decision made.
7.2.2 Acoustic measurement requirements
Add "(see 7.2.8)" at the end of 6th bullet of the first paragraph.
Add the following new subclause after 7.2.7:
7.2.8 Combining measurement series
When there are data available from different measurement series with differing environmental
conditions, then the data can only be combined using expert judgement. This may involve
pooling all the available data and analysing collectively, or it may involve analysing the
periods separately and combining the results. In the latter case, when there are overlapping
results then the method of weighted means, defined in Annex H, shall be used to combine
these into a single result.
The tonal analysis should always be based on pooling all the available data.
Where this is done, clear evidence shall be provided to justify the decisions made. This may,
for example, be accomplished by showing a scatter plot of the raw data colour coded for the
measurement series.
8 Non-acoustic measurements
8.2.1.1 Determination of wind speed through power curve
Add, in third sentence of the first paragraph, "closed" before the term "intervals" to read
"closed intervals".
Add, at the end of the first paragraph, the following new text:
Within the allowed range of the power curve, piece-wise linear interpolation shall be used to
define a continuous function between interval supporting points.
8.2.2 Wind speed measurements during background noise measurements
Replace, in the second paragraph, "κz" by "κ ".
Z
9 Data reduction procedures
9.2.4 Calculation of noise levels at bin centres including uncertainty
Replace Equation (20) by the following new equation:
L (t)= (1− t)⋅ L + t⋅ L (20)
i,k i,k+1
V,i
– 4 – IEC 61400-11:2012/AMD1:2018
© IEC 2018
Replace Equation (22) by the following new equation:
cov (t)
LV,i
u (t)= u (t)− (22)
L L,i
V,i
u (t)
V
where
2 2 2 2 2
u (t)= (1− t) ⋅ u + t ⋅ u
L,i com,L,i,k
com,L, i, k+1
cov cov
LV , i, k LV ,i, k+1
2 2
( ) ( )
cov t = 1− t ⋅ + t ⋅
LV ,i
N N
k k+1
2 2 2 2 2
u (t)= (1− t) ⋅ u + t ⋅ u
V com,V,k
com,V ,k+1
© IEC 2018
Replace Figure 7 by the following:
Procedure for tonality assessment
For each wind speed bin
Measuring
Spectra
10 or more
No
spectra
Yes
Identify possible
tones from local
maxima
If no possible tones,
Classify spectral
leave spectrum out of
lines in critical band
tonal audibility
through L
70%
analysis
If no identified tones,
Determine tone level,
leave spectrum out of
masking noise level,
tonal audibility
tonality and tonal
analysis
audibility
Average tonality for
tones of same "origin"
Average
No
∆L ≥ –3 dB
a
Yes
≥ 20 %
of all measured
No
spectra having an
identified tone
Yes
6 or more
spectra having an
No 30 or more measured No
identified tone
spectra
Yes
Yes
Report tone and tonal Report: No
audibility relevant tones
Finished
IEC
Tonality analysis procedure for each spectrum
– 6 – IEC 61400-11:2012/AMD1:2018
© IEC 2018
9.5.3 Classification of spectral lines within the critical band
Replace the third bulleted item under b) by the following:
• Where there are several lines classified as “tone”, the line having the greatest level is
identified. Lines are then only classified as “tone” if their levels are within 10 dB of the
highest level.
9.5.5 Determination of the tone level
Replace, in the first sentence of the first paragraph, 9.5.2 by 9.5.3.
Replace in the first paragraph, the sentence reading "This requires dividing the energy sum by
1,5" by the following:
This corresponds to subtracting –10·log(1/1,5) or 1,8 dB (1,76 dB) from the tone level.
9.5.8 Determination of audibility
Add, after "The Δl are energy averaged to one Δl for each tone of the same origin in
a,j,k a,k
each bin", the following new text:
For the tones of the same origin, the corresponding frequency to report is the range of
frequencies of the tone maxima of the individual spectra from Equation (34).
10 Information to be reported
10.5 Acoustic data
th
Replace the 9 bulleted item by the following:
• ΔL for each identified tone (as table or plot);
a,j,k
th
Delete the 10 bulleted item.
th
Replace the 11 bulleted item by the following:
• ΔL for each tone of the same origin;
a,k
th
Replace the 12 bulleted item by the following:
• frequency for each tone of the same origin;
© IEC 2018
Annex F – Small wind turbines
F.5 Tonal audibility
Replace the first sentence by the following:
The general methodology will be followed with the option of determination of tonal audibility
as follows.
F.6 Information to be reported
Replace the second paragraph by the following:
For small wind turbines, an immission map based on the determined sound power levels can
be reported. The immission map shall cover the wind speed range for which reportable sound
power levels are available. On the horizontal axis, the minimal value shall be the tower height
of the test turbine and the maximum value shall be chosen such that a representative part of
the 35 dB(A) contour line is showing. The sound pressure levels shall be calculated using
spherical spreading with a ground reflection correction of 1,5 dB. Sound pressure contours
shall be drawn for multiples of 5 dB (e.g. 30 dB(A), 35 dB(A), 40 dB(A) and 45 dB(A)). Note
that the immission map does not include penalties for tonality or similar as penalties are
subject to local regulations. If penalties from local regulations are included in the immission
map, a statement of this shall follow the map.
– 8 – IEC 61400-11:2012/AMD1:2018
© IEC 2018
Add the following new Annex H after Annex G:
Anne
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.