LAUSR

In recent years, a faulty leg is mostly replaced by a healthy leg for current fault-tolerant control of power converters, and its fault diagnosis only needs to confirm the fault leg. For fault-tolerant control, this paper proposed a real-time, robust and accurate diagnosis method for the legs of insulated gate bipolar transistor open-circuit faults in the pulse-width-modulated voltage source inverters for vector-controlled induction motors based on three-phase current. The covariance of three-phase current is used to diagnose and locate faults by analyzing the correlation between them, and its performance is explained specifically under both health condition and fault conditions. The proposed method is simple and no additional current or voltage sensors are required. The fault diagnosis time is about half a current cycle. Experiments are conducted and the obtained results demonstrate the effectiveness and merit of the proposed method.