Open-circuit fault diagnosis of transistor in inverter based on wavelet neural network

The paper presents a technique of fault detection and diagnosis for open-circuit fault of power device in inverter-fed motor drives based on wavelet neural network. The output current of the inverter is processed, and the recursive wavelet transform is used for fault detection. The layer detail coefficient and its energy are obtained by wavelet transform and the fault features are got by normalized the energy. BP neural network is used to isolate switch faults by input the fault features to the input layer of the network. The simulation result shows that the method can detect and isolate the faults effectively.