The reliability and safety of doubly fed induction generators (DFIGs) becomes extremely important in wind energy conversion systems (WECS). The present paper deals with a new approach of stator current sensor faults diagnosis for a DFIG-based wind turbine (WT). This approach uses a developed state space model of the DFIG by exploiting the maximum power extracted from the WT and a bank of Luenberger observers to generate residuals. The obtained residuals are used for stator current sensor fault detection. Furthermore, a logic algorithm is used to isolate the faulty sensor for a stator phase current fault. The validity of the proposed diagnosis scheme is investigated via simulation under multiple sensor faults. Simulation results are given to show the robustness of the proposed diagnosis approach.

Keywords: Faults diagnosis, Fault detection and isolation, Doubly fed induction generator (DFIG), Faulty stator phases