Dynamic behavior of doubly fed induction generator wind turbines under three-phase voltage dips

Nowadays, the most widely used variable speed wind turbine type for unites above 1MW is doubly fed induction generator (DFIG). Because of the relative small rating of the power converters, wind turbines based on the DFIG are very sensitive to grid disturbances, especially to voltage dips during grid faults. In this paper, two control strategies of the stator flux, including a synchronous approach with an open-loop flux control and an asynchronous approach with a closed-loop flux control, are proposed and compared in order to show their influence on the dynamic behavior of the wind turbine system against voltage dips.