Grid fault and design-basis for wind turbines (PSO 6319)

The objectives of this project are to investigate into the consequences of the new grid connection requirements for the fatigue and extreme loads of wind turbines. The goal is also to clarify and define possible new directions in the certification process of power plant wind turbines, namely wind turbines, which participate actively in the stabilisation of power systems. Practical experience shows that there is a need for such investigations. The grid connection requirements for wind turbines have increased significantly during the last 5-10 years. Especially the requirements for wind turbines to stay connected to the grid during and after voltage sags, imply potential challenges in the design of wind turbines. These requirements pose challenges for the design of both electrical and the mechanical structure of wind turbines. An overview over the frequency of grid faults and the grid connection requirements in different relevant countries will be done in this project. Different wind turbine concepts with their control strategies for operation during and after grid faults will be considered in these investigations. The project will focus on the quantification of the loads impact on the wind turbine lifetime. The main goal of this project is to develop of a procedure for the evaluation of the consequences of grid faults on the wind turbines loads. This procedure will be used directly in the certification of wind turbines.