International Standards and Conformity Assessment for all electrical, electronic and related technologies



Reference EN 61400-21:2008
Title Wind turbines - Part 21: Measurement and assessment of power quality characteristics of grid connected wind turbines
Project Number 21139
Abstract/Scope IEC 61400-21:2008 covers the definition and specification of the quantities to be determined for characterizing the power quality of a grid connected wind turbine; measurement procedures for quantifying the characteristics; and procedures for assessing compliance with power quality requirements, including estimation of the power quality expected from the wind turbine type. The main changes with respect to the previous edition deal with interharmonics and current distortions (<9 kHz); response to voltage dips; active power ramp rate limitation and set-point control; reactive power capabilities and set-point control; grid protection and reconnection time after grid faults.


Current Stage code 6060
Current Stage code date 2008-11-07
Current Stage code deadline 2009-07-01
Deadline date for vote  


Order Voucher  


IEC Technical Body IEC/TC 88
Reference Document IEC 61400-21:2008 (EQV)
ICS 27.180 - Wind turbine systems and other alternative sources of energy
Keywords Wind; Turbine; Power quality; Grid connected
Special National Condition(s)  


Categories - Aspects
Product Life Cycle


Deadline Date
6060 2008-11-07 2009-07-01 export to doc file  EN  FR  DE
5099 2008-10-01 2008-12-01  
5061 2008-08-26 2008-10-01  
5060 2008-07-15 2008-07-29 export to doc file  EN
5020 2008-05-09 2008-07-11  
3090 2008-02-22 2008-02-29  
5060 2007-07-16 2007-07-30 export to doc file  EN
5020 2007-02-09 2007-07-13  
1090 2007-02-06 2007-02-09  

Implementation Dates

date of Ratification (DOR) (1) 2008-10-01
date of Availability (DAV) (2) 2008-11-07
date of Announcement (DOA) (3) 2009-01-01
date of Publication (DOP) (4) 2009-07-01
date of Withdrawal (DOW) (5) 2011-10-01


Supersedes EN 61400-21:2002
Superseded by  
Normative reference (6) EN 60044-1:1999
EN 60044-2:1999
IEC 60050-161:1990
IEC 60050-415:1999
EN 61000-4-7:2002
EN 61000-4-15:1998
EN 61400-12-1:2006
EN 61800-3:2004
EN 62008:2005

(1) Date of ratification (dor) date when the Technical Board notes the approval of an EN (and HD for CENELEC), from which time the standard may be said to be approved

(2) Date of availability (dav) date when the definitive text in the official language versions of an approved CEN/CENELEC publication is distributed by the Central Secretariat

(3) Date of announcement (doa) latest date by which the existence of an EN (and HD for CENELEC), a TS or a CWA has to be announced at national level

(4) Date of publication (dop) latest date by which an EN has to be implemented at national level by publication of an identical national standard or by endorsement

(5) Date of withdrawal (dow) latest date by which national standards conflicting with an EN (and HD for CENELEC) have to be withdrawn

(6) This list of normative references is purely indicative. The only official list of normative reference is the list of the published standard.