IEC TS 61400-21-4:2025 specifies a uniform methodology, defining measurement, testing and assessment procedures of electrical characteristics of wind turbine components and subsystems, as basis for the verification of the electrical capabilities of wind turbines and wind turbine. IEC TS 61400-21-4:2025 specifies a uniform methodology, defining measurement, testing and assessment procedures of electrical characteristics of wind turbine components and subsystems, as basis for the verification of the electrical capabilities of wind turbines and wind turbine. ergy from EC co c r addresses the seventh of these effor emb nd areas in need of elivered by a single grid-connected WECS. for obtaining power quality data which can be used t co nt d ss it large WECS with Power Cond tioning Units. -. Wind turbine standards address design requirements and considerations, as well as associated components, systems, and technologies that have an impact on the reliable functioning of wind turbines. With the extensive IEC 61400 series covering topics as far ranging as full-scale structural testing. This standard BS EN IEC 61400-15-1:2025 Wind energy generation systems is classified in these ICS categories: IEC 61400-15-1:2025 defines a framework for assessment and reporting of the wind turbine suitability conditions for both onshore and offshore wind power plants. The power performance characterization of wind turbines of all types and sizes is covered.