IEC 61400-21:2008
Wind turbines - Part 21: Measurement and assessment of power quality characteristics of grid connected wind turbines

Standard No.

IEC 61400-21:2008

Release Date

2008

Published By

International Electrotechnical Commission (IEC)

Latest

IEC 61400-21:2008

Replace

IEC 88/317/FDIS:2008 IEC 61400-21:2001

Scope

This part of IEC 61400 includes: ~ 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; ~ procedures for assessing compliance with power quality requirements, including estimation of the power quality expected from the wind turbine type when deployed at a specific site, possibly in groups. The measurement procedures are valid for single wind turbines with a three-phase grid connection. The measurement procedures are valid for any size of wind turbine, though this part of IEC 61400 only requires wind turbine types intended for PCC (Point of Common Coupling) at MV or HV to be tested and characterized as specified in this part of IEC 61400. The measured characteristics are valid for the specific configuration and operational mode of the assessed wind turbine type only. Other configurations, including altered control parameters that cause the wind turbine to behave differently with respect to power quality, require separate assessment. The measurement procedures are designed to be as non-site-specific as possible, so that power quality characteristics measured at for example a test site can be considered valid also at other sites. The procedures for assessing compliance with power quality requirements are valid for wind turbines with PCC at MV or HV in power systems with fixed frequency within +1 Hz, and sufficient active and reactive power regulation capabilities. In other cases, the principles for assessing compliance with power quality requirements may still be used as a guidance. This part of IEC 61400 is for testing of wind turbines, though it contains information that may also be useful for testing of wind farms. NOTE This part of IEC 61400 uses the following terms for system voltage: - Iow voltage (LV) refers to Un ≤ 1 kV; - medium voltage (MV) refers to 1 kV < Un ≤ 35 kV; - high voltage (HV) refers to Un ＞ 35 kV.

IEC 61400-21:2008 Referenced Document

• IEC 60044-1 Instrument transformers - Part 1: Current transformers
• IEC 60044-2 Instrument transformers - Part 2: Inductive voltage transformers
• IEC 61000-4-7:2002 Electromagnetic compatibility (EMC) - Part 4-7: Testing and measurement techniques; General guide on harmonics and interharmonics measurements and instrumentation, for power supply systems and equipment connected thereto
• IEC 61400-12-1 Wind energy generation systems - Part 12-1: Power performance measurement of electricity producing wind turbines*， 2022-09-05 Update
• IEC 61800-3:2004 Adjustable speed electrical power drive systems - Part 3: EMC requirements and specific test methods
• IEC 62008 Performance characteristics and calibration methods for digital data acquisition systems and relevant software

IEC 61400-21:2008 history

• 2008 IEC 61400-21:2008 Wind turbines - Part 21: Measurement and assessment of power quality characteristics of grid connected wind turbines
• 2001 IEC 61400-21:2001 Wind turbine generator systems - Part 21: Measurement and assessment of power quality characteristics of grid connected wind turbines