CLC/TC 88 - Wind turbines

IEC 61400-8:2024 outlines the minimum requirements for the design of wind turbine nacelle-based structures and is not intended for use as a complete design specification or instruction manual. This document focuses on the structural integrity of the structural components constituted within and in the vicinity of the nacelle, including the hub, mainframe, main shaft, associated structures of direct-drives, gearbox structures, yaw structural connection, nacelle enclosure. It also addresses connections of the structural components to control and protection mechanisms, as well as structural connections of electrical units and other mechanical systems. This document focuses primarily on ferrous material-based nacelle structures but can apply to other materials also as appropriate

IEC 61400-21-2 - Wind energy generation systems - Measurement and assessment of electrical characteristics - Wind power plants - has the following scope: IEC 61400-21-2 defines and specifies the quantities that shall be determined to characterize the electrical characteristics of grid-connected power plants (PP). IEC 61400-21-2 defines the measurement and test procedures for quantifying the electrical characteristics as basis for the verification of compliance of PP, including: - Power quality aspects - Steady state operation - Dynamic response (undervoltage and overvoltage fault ride-through) - Disconnection from grid (Grid protection) - Control performance IEC 61400-21-2 defines a uniform functionality test and measurement procedure for the power plant controller (PPC), as a basis for the unit test of the power plant controller. IEC 61400-21-2 defines the procedures for assessing compliance with electrical connection requirements, including the aggregation methods for power quality aspects such as voltage variations, flicker, harmonics and interharmonics. IEC 61400-21-2 defines the procedures for measurement and fault recording for the verification of power plant electrical simulation models in relation to undervoltage and overvoltage ride through events. These measurement procedures are valid for power plants, including the power plant controller and other connected equipment, necessary for the operation of the Power Plant. The measurement procedures are valid for any size of power plant connected to the point of connection (POC) at one connection point. The procedures for assessing and verifying the compliance with grid connection requirements are valid for power plants in power systems with fixed frequency and a sufficient short-circuit power. Out of the scope of this standard are: - Multi park control, i.e. cluster management of several power plants (PP) or several connection points - Compliance test and performance requirements, including pass or fail criteria - Specific component test and validation of the PP equipment (switchgear, cables, transformers, etc.), which are covered by other IEC standards - Wind power plant model validation, as defined in the IEC 61400-27-2 - Load flow calculation methods and load flow study guidelines - Test and measurement of the communication interface and system of the PP as defined in the IEC 61400-25 series NOTE For the purposes of this document, the following terms for system voltage apply, based on IEC 60038 Low voltage (LV) refers to 100 V  230 kV

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).

The IEC 61400 series of standards addresses wind energy generation technical requirements up to the point of interconnection with the utility grid system. Part 12 of the IEC 61400 series of standards comprises a sub-set of standards which are to be used in the evaluation and measurement of the power performance characteristics of wind turbines. The power performance characterisation of wind turbines of all types and sizes is covered. Wind turbine power performance characteristics are determined from a measured power curve and an associated estimated annual energy production (AEP) and its uncertainty. The measured power curve, defined as the relationship between the wind speed and the wind turbine power output, is determined by collecting simultaneous measurements of meteorological variables (including wind speed), as well as wind turbine signals (including power output) at the test site 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 AEP is calculated by applying the measured power curve to reference wind speed frequency distributions, assuming 100 % availability. Part 12-0 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. Although the -12 series also defines the specifications of the meteorological variables (and in particular wind speed) required for the power performance evaluation, the methods and procedures for measuring or otherwise acquiring the wind speed data are defined in the IEC 61400-50 wind measurement series of standards. The evaluation of the wind turbine power performance characteristic according to this series of standards requires the measured power curve and derived energy production figures to be supplemented by an assessment of uncertainty sources and their combined effects. The basis of the uncertainty assessment is ISO/IEC Guide 98-3. The wind measurement uncertainty sources shall be identified and quantified from procedures described in the relevant wind measurement standards contained in the IEC 61400-50 series. The wind measurement uncertainties shall be propagated through to and combined with the other sources of uncertainty in the power curve and annual energy production using methods and assumptions described in the IEC 61400-12 series of standards.

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 61400-12-2:2022 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.

Part 50 of IEC 61400 specifies methods and requirements for the application of instruments to measure wind speed (and related parameters, e.g. wind direction and 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 testing) described by other standards in the IEC 61400 series. Part 50-2 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.

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 61400-12-6:2022 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 61400-12-3:2022 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.

This part of IEC 61400 specifies additional requirements for assessment of the external conditions at an offshore wind turbine site and specifies essential design requirements to ensure the engineering integrity of fixed offshore wind turbines. Its purpose is to provide an appropriate level of protection against damage from all hazards during the planned lifetime. This document focuses on the engineering integrity of the structural components of an offshore wind turbine but is also concerned with subsystems such as control and protection mechanisms, internal electrical systems and mechanical systems. A wind turbine shall be considered as a fixed offshore wind turbine if the support structure is subject to hydrodynamic loading and it is founded on the seabed. The design requirements specified in this document are not sufficient to ensure the engineering integrity of floating offshore wind turbines. For floating installations, reference is made to IEC 61400-3-2. In the remainder of this document, the term "offshore wind turbine" is assumed to refer to those that are fixed to the seabed. This document should be used together with the appropriate IEC and ISO standards mentioned in Clause 2. In particular, this document is fully consistent with the requirements of IEC 61400-1. The safety level of the offshore wind turbine designed according to this document shall be at or exceed the level inherent in IEC 61400-1. In some clauses, where a comprehensive statement of requirements aids clarity, replication of text from IEC 61400-1 is included.

IEC 61400-24:2019 applies to lightning protection of wind turbine generators and wind power systems. Refer to guidelines for small wind turbines in annex. This document defines the lightning environment for wind turbines and risk assessment for wind turbines in that environment. It defines requirements for protection of blades, other structural components and electrical and control systems against both direct and indirect effects of lightning. Test methods to validate compliance are included. Guidance on the use of applicable lightning protection, industrial electrical and EMC standards including earthing is provided. This second edition cancels and replaces the first edition, published in 2010. This edition includes the following significant technical changes with respect to the previous edition: a) it is restructured with a main normative part, while informative information is placed in annexes.

IEC 61400-26-1:2019 defines an information model from which time-based, and production-based availability indicators for services can be derived and reported. The purpose is to provide standardised metrics that can be used to create and organise methods for availability calculation and reporting according to the user’s needs. The document provides information categories, which unambiguously describe how data is used to characterise and categorise the operation. The information model specifies category priority for discrimination between possible concurrent categories. Further, the model defines entry and exit criteria to allocate fractions of time and production values to the proper information category. A full overview of all information categories, exit and entry criteria is given in Annex. The document can be applied to any number of WTGSs, whether represented by an individual turbine, a fleet of wind turbines, a wind power station or a portfolio of wind power stations. A wind power station is typically made up of all WTGSs, functional services and balance of plant elements as seen from the point of common coupling. This first edition cancels and replaces IEC TS 61400-26-1:2011, IEC TS 61400-26-2:2014 and IEC TS 61400-26-3:2016.

IEC 61400-21-1:2019 includes: · definition and specification of the quantities to be determined for characterizing the electrical characteristics of a grid-connected wind turbine; · measurement procedures for quantifying the electrical characteristics; · procedures for assessing compliance with electrical connection requirements, including estimation of the power quality expected from the wind turbine type when deployed at a specific site. 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 connection to an electricity supply network to be tested and characterized as specified in this part of IEC 61400. This first edition cancels and replaces the second edition of 61400-21 published in 2008. This edition includes the following new items with respect to 61400-21: a) frequency control measurement; b) updated reactive power control and capability measurement, including voltage and cos φ control; c) inertia control response measurement; d) overvoltage ride through test procedure; e) updated undervoltage ride through test procedure based on Wind Turbine capability; f) new methods for the harmonic assessment.

IEC 61400-1:2019 is available as IEC 61400-1:2019 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 61400-1:2019 specifies essential design requirements to ensure the structural integrity of wind turbines. Its purpose is to provide an appropriate level of protection against damage from all hazards during the planned lifetime. This document is concerned with all subsystems of wind turbines such as control and protection functions, internal electrical systems, mechanical systems and support structures. This document applies to wind turbines of all sizes. For small wind turbines, IEC 61400-2 can be applied. IEC 61400-3-1 provides additional requirements to offshore wind turbine installations. This document is intended to be used together with the appropriate IEC and ISO standards mentioned in Clause 2. This edition includes the following significant technical changes with respect to the previous edition: a) general update and clarification of references and requirements; b) extension of wind turbine classes to allow for tropical cyclones and high turbulence; c) Weibull distribution of turbulence standard deviation for normal turbulence model (NTM); d) updated design load cases (DLCs), in particular DLC 2.1 and 2.2; e) revision of partial safety factor specifications The contents of the corrigendum of September 2019 have been included in this copy.

The purpose of this part of IEC 61400 is to describe procedures and methods that ensure that wind measurements using nacelle-mounted wind lidars are carried out and reported consistently and according to best practice. This document does not prescribe the purpose or use case of the wind measurements. However, as this document forms part of the IEC 61400 series of standards, it is anticipated that the wind measurements will be used in relation to some form of wind energy test or resource assessment. The scope of this document is limited to forward-looking nacelle-mounted wind lidars (i.e. the measurement volume is located upstream of the turbine rotor). This document aims to be applicable to any type and make of nacelle-mounted wind lidar. The method and requirements provided in this document are independent of the model and type of instrument, and also of the measurement principle and should allow application to new types of nacelle-mounted lidar. This document aims to describe wind measurements using nacelle-mounted wind lidar with sufficient quality for the use case of power performance testing (according to IEC 61400-12-1:2017). Readers of this document should consider that other use cases may have other specific requirements. This document only provides guidance for measurements in flat terrain and offshore as defined in IEC 61400-12-1:2017, Annex B. Application to complex terrain has been excluded from the scope due to limited experience at the time of writing this document. Corrections for induction zone or blockage effects are not included in the scope of this document. However, such correction or uncertainty estimation due to blockage effects may be applied if required by the use case, under the responsibility of the user. The purpose of this document is to provide guidance for wind measurements. HSE requirements (e.g. laser operation) are out of the scope of this document although they are important.

The contents of the corrigendum of October 2019 have been included in this copy.

2021-06-11 - IEC Corrected version

TAN - // IEC Corrigendum

NEW!IEC 61400-25-1:2017 is available as IEC 61400-25-1:2017 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 61400-25-1:2017 gives an overall description of the principles and models used in the IEC 61400­25 series, which is designed for a communication environment supported by a client-server model. Three areas are defined, that are modelled separately to ensure the scalability of implementations: wind power plant information models, information exchange model, and mapping of these two models to a standard communication profile. This new edition includes the following significant technical changes with respect to the previous edition: general harmonization of text and overview models with the other parts of the IEC 61400­25 series, harmonization of definitions in other related standards.

2020-05-07: When amdt is published, add supersession link between PR=64419 and PR=21139

2020-05-07: When amdt is published, add supersession link between PR=65214 and PR=21445

IEC 61400-25-5:2017 specifies standard techniques for testing of compliance of implementations, as well as specific measurement techniques to be applied when declaring performance parameters. The use of these techniques will enhance the ability of users to purchase systems that integrate easily, operate correctly, and support the applications as intended. This part of IEC 61400-25 defines: the methods and abstract test cases for compliance testing of server and client devices used in wind power plants; the metrics to be measured in said devices according to the communication requirements specified in IEC 61400-25 (all parts). This new edition includes the following significant technical changes with respect to the previous edition: - harmonization with structure and test cases in IEC 61850-10:2012; - reduction of overlap between standards and simplification by increased referencing to the IEC 61850 standard series.

IEC 61400-27-2:2020 specifies procedures for validation of electrical simulation models for wind turbines and wind power plants, intended to be used in power system and grid stability analyses. The validation procedures are based on the tests specified in IEC 61400-21 (all parts). The validation procedures are applicable to the generic models specified in IEC 61400-27-1 and to other fundamental frequency wind power plant models and wind turbine models. The validation procedures for wind turbine models focus on fault ride through capability and control performance. The fault ride through capability includes response to balanced and unbalanced voltage dips as well as voltage swells. The control performance includes active power control, frequency control, synthetic inertia control and reactive power control. The validation procedures for wind turbine models refer to the tests specified in IEC 61400-21-1. The validation procedures for wind turbine models refer to the wind turbine terminals.

IEC 61400-27-1:2020 defines standard electrical simulation models for wind turbines and wind power plants. The specified models are time domain positive sequence simulation models, intended to be used in power system and grid stability analyses. The models are applicable for dynamic simulations of short term stability in power systems. This document defines the generic terms and parameters for the electrical simulation models. This document specifies electrical simulation models for the generic wind power plant topologies / configurations currently on the market. The wind power plant models include wind turbines, wind power plant control and auxiliary equipment. The wind power plant models are described in a modular way which can be applied for future wind power plant concepts and with different wind turbine concepts.

IEC 61400-5:2020 specifies requirements to ensure the engineering integrity of wind turbine blades as well as an appropriate level of operational safety throughout the design lifetime. It includes requirements for:  
aerodynamic and structural design,
material selection, evaluation and testing,
manufacture (including associated quality management),
transportation, installation, operation and maintenance of the blades.  The purpose of this document is to provide a technical reference for designers, manufacturers, purchasers, operators, third party organizations and material suppliers, as well as to define requirements for certification.

IEC 61400-6:2020 specifies requirements and general principles to be used in assessing the structural integrity of onshore wind turbine support structures (including foundations). The scope includes the geotechnical assessment of the soil for generic or site specific purposes. The strength of any flange and connection system connected to the rotor nacelle assembly (including connection to the yaw bearing) are designed and documented according to this document or according to IEC 61400-1. The scope includes all life cycle issues that may affect the structural integrity such as assembly and maintenance.

TAN - // IEC Corrigendum

NEW!IEC 61400-12-1:2017 is 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

IEC 61400-25-6:2016(E) specifies the information models related to condition monitoring for wind power plants and the information exchange of data values related to these models. This standard is to be used with other standards of the IEC 61400-25 series. This new edition includes the following significant technical changes with respect to the previous edition: - major restructuring of the data model to accommodate flexibility; removal of UFF58 format; - access to data using the standard reporting and logging functions; - recommendations for creating data names to accommodate flexibility.

IEC 61400-25-4:2008(E) specifies the specific mappings to protocol stacks encoding the messages required for the information exchange between a client and a remote server for data access and retrieval, device control, event reporting and logging, publisher/subscriber, self-description of devices (device data dictionary), data typing and discovery of data types. Covers several mappings, one of which shall be selected in order to be compliant with this part of IEC 61400-25. The IEC 61400-25 series is designed for a communication environment supported by a client-server model. Three areas are defined, that are modelled separately to ensure the scalability of implementations: wind power plant information model, information exchange model, and mapping of these two models to a standard communication profile. This publication is of high relevance for Smart Grid.

This document presents measurement procedures that enable noise emissions of a wind turbine to be characterised. This involves using measurement methods appropriate to noise emission assessment at locations close to the machine, in order to avoid errors due to sound propagation, but far away enough to allow for the finite source size. The procedures described are different in some respects from those that would be adopted for noise assessment in community noise studies. They are intended to facilitate characterisation of wind turbine noise with respect to a range of wind speeds and directions. Standardisation of measurement procedures will also facilitate comparisons between different wind turbines. The procedures present methodologies that will enable the noise emissions of a single wind turbine to be characterised in a consistent and accurate manner. These procedures include the following: - location of acoustic measurement positions; - requirements for the acquisition of acoustic, meteorological, and associated wind turbine operational data; - analysis of the data obtained and the content for the data report; and - definition of specific acoustic emission parameters, and associated descriptors which are used for making environmental assessments. This International Standard is not restricted to wind turbines of a particular size or type. The procedures described in this standard allow for the thorough description of the noise emission from a wind turbine. A method for small wind turbines is described in Annex F.

This part of IEC 61400 deals with safety philosophy, quality assurance, and engineering
integrity and specifies requirements for the safety of small wind turbines (SWTs) including
design, installation, maintenance and operation under specified external conditions. Its
purpose is to provide the appropriate level of protection against damage from hazards from
these systems during their planned lifetime.
This standard is concerned with all subsystems of SWTs such as protection mechanisms,
internal electrical systems, mechanical systems, support structures, foundations and the
electrical interconnection with the load. A small wind turbine system includes the wind turbine
itself including support structures, the turbine controller, the charge controller / inverter (if
required), wiring and disconnects, the installation and operation manual(s) and other
documentation.
While this standard is similar to IEC 61400-1, it does simplify and make significant changes in
order to be applicable to small wind turbines. Any of the requirements of this standard may be
altered if it can be suitably demonstrated that the safety of the turbine system is not
compromised. This provision, however, does not apply to the classification and the associated
definitions of external conditions in Clause 6. Compliance with this standard does not relieve
any person, organisation, or corporation from the responsibility of observing other applicable
regulations.
This standard applies to wind turbines with a rotor swept area smaller than or equal to
200 m2, generating electricity at a voltage below 1 000 V a.c. or 1 500 V d.c. for both on-grid
and off-grid applications.
This standard should be used together with the appropriate IEC and ISO standards (see
Clause 2).

This part of IEC 61400 specifies essential design requirements to ensure the structural
integrity of wind turbines. Its purpose is to provide an appropriate level of protection against
damage from all hazards during the planned lifetime.
This document is concerned with all subsystems of wind turbines such as control and
protection functions, internal electrical systems, mechanical systems and support structures.
This document applies to wind turbines of all sizes. For small wind turbines, IEC 61400-2 can
be applied. IEC 61400-3-1 provides additional requirements to offshore wind turbine
installations.
This document is intended to be used together with the appropriate IEC and ISO standards
mentioned in Clause 2.

IEC 61400-13:2015(B) describes the measurement of fundamental structural loads on wind turbines for the purpose of the load simulation model validation. The standard prescribes the requirements and recommendations for site selection, signal selection, data acquisition, calibration, data verification, measurement load cases, capture matrix, post-processing, uncertainty determination and reporting. Informative annexes are also provided to improve understanding of testing methods. This standard replaces IEC TS 61400-13 published in 2001; it constitutes a technical revision and transition from technical specification to International Standard.

IEC 61400-25-3:2015 is available as IEC 61400-25-3:2015 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition. IEC 61400-25-3:2015 specifies an abstract communication service interface describing the information exchange between a client and a server for: - data access and retrieval, - device control, - event reporting and logging, - self-description of devices (device data dictionary), - data typing and discovery of data types. Main changes with respect to the previous edition consist of: - harmonization with newer editions of IEC 61850 standards; - reduction of overlap between standards and simplification by increased referencing, etc.

IEC 61400-25-2:2015 specifies the information model of devices and functions related to wind power plant applications. In particular, it specifies the compatible logical node names, and data names for communication between wind power plant components. This includes the relationship between logical devices, logical nodes and data. The names defined in the IEC 61400-25 series are used to build the hierarchical object references applied for communicating with components in wind power plants. Main changes with respect to the previous edition consist of: - harmonization with newer editions of IEC 61850 standards; - reduction of overlap between standards and simplification by increased referencing, - extension of data objects for operation of smart grids, - extended and enhanced semantics for existing data objects, etc.

Gives guidelines for declaring the apparent sound power level and tonality of a batch of wind turbines. Is to be used in conjunction with IEC 61400-11 which gives measurement procedures for apparent sound power level and tonality. This publication is of high relevance for Smart Grid.

Is a technical specification providing guidelines for the full-scale structural testing of wind turbine blades and for the interpretation or evaluation of results, as a possible part of a design verification of the integrity of the blade. Includes static strength tests, fatigue tests, and other tests determining blade properties. This publication is of high relevance for Smart Grid.

IEC 61400-2:2013 deals with safety philosophy, quality assurance, and engineering integrity and specifies requirements for the safety of small wind turbines (SWTs) including design, installation, maintenance and operation under specified external conditions. It provides the appropriate level of protection against damage from hazards from these systems during their planned lifetime. This standard is concerned with all subsystems of SWTs such as protection mechanisms, internal electrical systems, mechanical systems, support structures, foundations and the electrical interconnection with the load. While this standard is similar to IEC 61400-1, it does simplify and make significant changes in order to be applicable to small wind turbines. The main changes with respect to the previous edition are as follows: - the title has been modified to better reflect the scope; - restructured into a part Design evaluation and a part Type testing to harmonise use with IEC 61400-22 conformity testing and certification; - caution provided regarding the use of simplified equations; - added various annexes (wind conditions, tropical storms, extreme environmental conditions, EMC testing, dynamic behavior, etc.).

IEC Corrigendum

IEC 61400-12-2:2013 specifies a procedure for verifying the power performance characteristics of a single electricity-producing, horizontal axis wind turbine, which is not considered to be a small wind turbine per IEC 61400-2. This standard is intended to be used when the specific operational or contractual specifications may not comply with the requirements set forth in IEC 61400-12-1:2005. The procedure can be used for power performance evaluation of specific turbines at specific locations, but equally the methodology can be used to make generic comparisons between different turbine models or different turbine settings.

IEC 61400-4:2012(E) is applicable to enclosed speed increasing gearboxes for horizontal axis wind turbine drivetrains with a power rating in excess of 500 kW. This standard applies to wind turbines installed onshore or offshore. It Standard provides guidance on the analysis of the wind turbine loads in relation to the design of the gear and gearbox elements. The gearing elements covered by this standard include such gears as spur, helical or double helical and their combinations in parallel and epicyclic arrangements in the main power path. The standard is based on gearbox designs using rolling element bearings. Also included is guidance on the engineering of shafts, shaft hub interfaces, bearings and the gear case structure in the development of a fully integrated design that meets the rigours of the operating conditions. Lubrication of the transmission is covered along with prototype and production testing. Finally, guidance is provided on the operation and maintenance of the gearbox.

IEC 61400-11:2012(E) presents measurement procedures that enable noise emissions of a wind turbine to be characterised. This involves using measurement methods appropriate to noise emission assessment at locations close to the machine, in order to avoid errors due to sound propagation, but far away enough to allow for the finite source size. The procedures described are different in some respects from those that would be adopted for noise assessment in community noise studies. They are intended to facilitate characterisation of wind turbine noise with respect to a range of wind speeds and directions. Standardisation of measurement procedures will also facilitate comparisons between different wind turbines. This new edition constitutes a technical revision, introducing new principles for data reduction procedures.

This European Standard specifies requirements for protective measures relating to the health and safety of personnel, relevant to commissioning, operation and maintenance of wind turbines. It does not describe instructions and provisions for safe working during manufacture, transport, assembly and installation of the wind turbine. Requirements are specified regarding – hardware provisions being a part of the turbine such as platforms, ladders, lighting, – manuals and warning signs to accommodate safe and quick operation, inspection and maintenance. The requirements and/or measures specified account for the hazards – of mechanical origin such as falling, slipping, locking in, – of thermal origin (fire) such as burns by flames or explosions, – of electricity such as contact with live parts, – generated by noise such as stress and loss of hearing, – generated by neglecting ergonomic principles in machine design such as unhealthy postures or human errors. This standard is prepared for horizontal axis, grid connected wind turbines. For other concepts (e.g. vertical axis turbines) the principles are still valid, but the specific rules or requirements have to be adjusted to the actual concept. Additional provisions and procedures are necessary for turbines installed in water or offshore. The present document only draws attention to these. Provisions and procedures for lifts and Suspended Access Equipment (SAE) in the turbine tower are not included in this standard. This standard is not applicable to wind turbines manufactured before the date of its publication by CENELEC.

This Technical Report provides guidance on requirements for the electromagnetic compatibility of wind turbines of all sizes, to assist with achieving compliance with EMC standards. This Technical Report includes guidance on emissions, and for immunity to external disturbances. Safety related aspects are not included in this Technical Report. They are the subject of relevant parts of EN 61400. This Technical Report is applicable to electromagnetic emissions and immunity, both conducted and radiated, in the range 0 Hz to 400 GHz (although generally EMC standards do not at present contain test methods or limits at frequencies above 1 GHz). Fault conditions are not taken into account. This Technical Report does not include test procedures, conditions, limits, or reference values; these requirements are included in relevant parts of EN 61000, which are referred to in this Technical Report where necessary. This Technical Report also provides guidance for wind turbine installations (wind farms or single machines). The electromagnetic compatibility of components within the wind turbine (i.e. within enclosed parts of the wind turbine, which may include the hub, nacelle and tubular tower) with each other is solely a matter for the wind turbine manufacturer. The physical impact of the structure on the reception of radio services in the vicinity needs to be considered as a separate issue, and is not dealt with in this Technical Report. It should be noted that although experience to date has shown that physical interference to broadcasting services has caused the majority of complaints, wind turbines are capable of interfering with all radio services to some extent.