In this report the present-day design and testing methods of wind turbine components are presented with a particular focus on the wind turbine gearbox, pitch system and yaw system. The report lists the common drive train concepts and describes the actual component design procedure starting from aeroelastic turbine simulations to limit states analysis and verification. Specific attention is given to the present-day method of load transfer from the global aeroelastic simulations to the component design loads and the pitfalls in the current design procedure. Furthermore, the report presents the state-ofthe- art measurement approach and how the measurements are used to support the design process and certification of a wind turbine and its components. Special attention is given to the procedures that derive life time loads from measurement loads.
As another main focus of this report, different load validation procedures are discussed. Since measurement data are used for the validation of design loads, different approaches are currently used to compare the measurement quantities and the design values. The design and certification of wind turbines is based on a number of guidelines and standards. These are summarised and evaluated in this report. Also, the practice of wind turbine type certification and project certification is taken into account.
The conclusions of this report will establish why the PROTEST project is necessary, and proposals for improved design as well as for the measurement and certification approaches are derived from the conclusions of this report.