MT 12-1 - TC 88/MT 12-1

IEC 61400-50-1:2022 specifies methods and requirements for the application of instruments to measure wind speed (and related parameters, e.g. wind direction, turbulence intensity). Such measurements are required as an input to some of the evaluation and testing procedures for wind energy and wind turbine technology (e.g. resource evaluation and turbine performance testing) described by other standards in the IEC 61400 series. This document is applicable specifically to the use of wind measurement instruments mounted on meteorological masts, turbine nacelles or turbine spinners which measure the wind at the location at which the instruments are mounted. This document excludes remote sensing devices which measure the wind at some location distant from the location at which the instrument is mounted (e.g. vertical profile or forward facing lidars).

IEC 61400-12-1:2022 specifies a procedure for measuring the power performance characteristics of a single wind turbine and applies to the testing of wind turbines of all types and sizes connected to the electrical power network. In addition, this document defines a procedure to be used to determine the power performance characteristics of small wind turbines (as defined in IEC 61400-2) when connected to either the electric power network or a battery bank. This document defines a measurement methodology that requires the measured power curve and derived energy production figures to be supplemented by an assessment of uncertainty sources and their combined effects. This third edition of IEC 61400-12-1 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.

IEC 61400-12:2022 defines procedures for assessing the power performance characteristics of wind turbines. This document provides a general introduction to the available options for power performance measurement and the contributing evaluations which are further detailed in the other parts of the IEC 61400-12 series. This first edition of IEC 61400-12 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.

IEC 61400-12-2:2022 specifies a procedure for verifying the power performance characteristics of a single electricity-producing, horizontal axis wind turbine that is not considered to be a small wind turbine per IEC 61400-2. It is expected that this document be used when the specific operational or contractual specifications do not comply with the requirements set out in IEC 61400-12-1. The purpose of this document is to provide a uniform methodology of measurement, analysis, and reporting of power performance characteristics for individual electricity producing wind turbines utilising nacelle-anemometry methods. This document is intended to be applied only to horizontal axis wind turbines of sufficient size that the nacelle-mounted anemometer does not significantly affect the flow through the turbine’s rotor and around the nacelle and hence does not affect the wind turbine’s performance. This second edition of IEC 61400-12-2 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.

IEC 61400-12-5:2022 specifies the procedures for assessing the significance of obstacles and terrain variations on a proposed power performance measurement site and applies to the performance testing of wind turbines of all types and sizes connected to the electrical power network as described in other parts of the IEC 61400 series. The procedure applies to the performance evaluation of specific wind turbines at specific locations.
This first edition of IEC 61400-12-5 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.

IEC 61400-12-6:2022 specifies a procedure for measuring the nacelle transfer function of a single electricity-producing, horizontal axis wind turbine, which is not considered to be a small wind turbine in accordance with IEC 61400-2. It is expected that this document be used when a valid nacelle transfer function is needed to execute a power performance measurement according to IEC 61400-12-2. This document specifies how to characterise a wind turbine's nacelle transfer function. The nacelle transfer function is determined by collecting simultaneous measurements of nacelle‑measured wind speed and free stream wind speed (as measured on a meteorological mast) for a period that is long enough to establish a statistically significant database over a range of wind speeds and under varying wind and atmospheric conditions. The procedure also provides guidance on determination of measurement uncertainty including assessment of uncertainty sources and recommendations for combining them.
This first edition of IEC 61400-12-6 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.

IEC 61400-50-2:2022 is applicable specifically to the use of ground-mounted remote sensing wind measurement instruments, i.e. devices which measure the wind at some location generally above and distant from the location at which the instrument is mounted (e.g. sodars, vertical profiling lidars). This document specifically excludes other types of RSD such as forward facing or scanning lidars. This document specifies the following: a. the procedure and requirements for classifying ground-based RSDs in order to assess the uncertainty pertaining from sensitivity of the RSD response to meteorological conditions that can vary between the RSD calibration place and time and the use case (specific measurement campaign – SMC) place and time; b. the procedures and requirements for calibration of RSDs; c. the assessment of wind speed measurement uncertainty; d. additional checks of the RSD performance and measurement uncertainty during the SMC; e. application of the wind speed uncertainty derived from the RSD calibration and classification to the measurements taken during the SMC (e.g. interpolation of uncertainty or calibration results to different heights); f. requirements for reporting. This first edition of IEC 61400-50-2 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.

IEC 61400-50:2022 provides a general introduction to the options that are available for wind measurement, which are further detailed in the other parts of the IEC 61400-50 series. Tandis que ces autres normes définissent les cas d’utilisation relatifs aux mesurages du vent, la série IEC 61400-50 établit des exigences de mesure du vent qui sont indépendantes des cas d’utilisation. Son objectif est d’assurer que les mesurages du vent et l’évaluation des incertitudes (relative à ces mesurages) sont effectués de manière cohérente dans tout le secteur éolien; et d’assurer que ces mesurages du vent sont effectués de telle sorte que les incertitudes pouvant être quantifiées soient dans une plage acceptable.
This first edition of IEC 61400-50 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.

IEC 61400-12-3:2022 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. 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 provides guidance in the measurement, analysis, and reporting of the site calibration for subsequent use in power performance testing for wind turbines.
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.

IEC 61400-12-1:2017 is also available as IEC 61400-12-1:2017 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 61400-12-1:2017 specifies a procedure for measuring the power performance characteristics of a single wind turbine and applies to the testing of wind turbines of all types and sizes connected to the electrical power network. In addition, this standard describes a procedure to be used to determine the power performance characteristics of small wind turbines (as defined in IEC 61400-2) when connected to either the electric power network or a battery bank. The procedure can be used for performance evaluation of specific wind turbines at specific locations, but equally the methodology can be used to make generic comparisons between different wind turbine models or different wind turbine settings when site-specific conditions and data filtering influences are taken into account. This new edition includes the following significant technical changes with respect to the previous edition: new definition of wind speed, inclusion of wind shear and wind veer, revision of air density correction, revision of site calibration, revision to definition of power curve, interpolation to bin centre method, revision of obstacle model, etc.
Key words: Wind turbines, Wind energy, renewable energy, performance, efficiency
The contents of the corrigendum 1 of September 2019, corrigendum 2 of March 2020 and corrigendum 3 of May 2021 have been included in this copy.