WG 26 - TC 88/WG 26

IEC TS 61400-26-4:2024, which is a Technical Specification, specifies terms and information categories for identification and reporting of reliability metrics. The definitions are applicable to key components, any number of wind turbines, fleets of wind turbine types, a wind power station or a portfolio of wind power stations. The wind power station is made up of all WTGSs (Wind Turbine Generator Systems), functional services and balance of plant elements as seen from the point of common coupling.
This document provides guidelines regarding reliability methodologies with informative annexes regarding use.
It expands on the information model in IEC 61400-26-1, recognizing that availability and reliability are interrelated.

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 TS 61400-26-3:2016(E) provides a framework from which time-based and production-based availability indicators of a wind power station can be derived. It unambiguously describes how data is categorised and provides examples of how the data can be used to derive availability indicators. The approach is to apply the terms and definitions for the applied information models introduced in IEC TS 61400-26-1 and IEC TS 61400-26-2 to a wind power station.

IEC TS 61400-26-2:2014 provides a framework from which production-based performance indicators of a wind turbine generator system can be derived. It unambiguously describes how data is categorised and provides examples of how the data can be used to derive performance indicators. The approach of this part of IEC 61400 is to expand the time allocation model, introduced in IEC TS 61400-26-1, with two additional layers for recording of the actual energy production and potential energy production associated with the concurrent time allocation. This document also includes informative annexes with:
- examples of determination of lost production,
- examples of algorithms for production-based indicators,
- examples of other performance indicators,
- examples of application scenarios.

IEC 61400-26-1:2011(E) defines generic information categories to which fractions of time can be assigned for a wind turbine generating system (WTGS) considering internal and external conditions based on fraction of time and specifying the following:
- generic information categories of a WTGS considering availability and other performance indicators;
- information category priority in order to discriminate between concurrent categories;
- entry and exit point for each information category in order to allocate designation of time;
- informative annexes providing various examples.