Single-phase PWM Open Circuit Fault Diagnosis Based on Improved ResNet-50

Single-phase PWM is an important part of the traction drive system, its performance will directly affect the performance of the whole system. IGBT fault has become the mainstream of research, when the circuit device short circuit fault, the voltage and current will rise rapidly in a short time, and eventually lead to the occurrence of an open circuit fault. Therefore, particular attention is given to the open circuit failure of IGBT. This paper proposed a fault diagnosis method based on an improved ResNet-50 algorithm. First, to obtain the characteristic information of the signal, the input signal of the network side is converted into grayscale images by signal reconstruction, which preserves the information contained in the signal to a large extent. Second, in the diagnostic model, the attention mechanism is added to the original ResNet-50, and the network parameters are optimized to improve the network performance. Ultimately, the accuracy of the simulation experiment reaches $96 \%$, which is better than other networks. The result proves the validity of the method.