Variable Speed Wind Turbine DFIG Back to Back Converters Open-Circuit Fault Diagnosis by Using of Combiniation Signal-Based and Model-Based Methodes

Condition monitoring (CM) and Fault Detection (FD) of wind turbine lead to increase in reliability and availability of turbine. IGBT open circuit of wind turbine converter will bring about depletion in output current of converter and as a result, reduction in production of wind turbine power. In this research, back to back converter IGBT open - gate fault for wind turbine based on DFIG is detection at first and then it is isolated. The proposed method is low cost and it does not use extra sensor for fault detection and isolation. Fault detection is based on model-based strategy, for residual generation an observer based on Kalman model are used, this model is based on the extraction grid side and rotor side DFIG three-phase currents state matrix and then residual evaluation is conducted. Fault location is determined on signal-based strategy and mean feature extraction of time signal. To evaluate the suggested structure, a 2.5MW wind turbine simulator is used according to real data. Simulations have shown that the proposed method, diagnostics the synchronous and multiple faults in one LEG or different LEGs of grid side and rotor side.