Open-Circuit Failure Analysis and Diagnosis of High Output Frequency Multilevel Inverter for Superspeed Maglev Train

Superspeed maglev train can reach the speed of 1000 kilometers per hour, or even 2 to 3 times the sound speed. Linear motor is often used in maglev train, when the linear motor parameters are constant, the maximum speed of the train depends on the output frequency of the traction converter. Due to the large switching loss of high-voltage and high-power power devices, the output frequency of traditional high-power maglev traction converter is limited to 500Hz, to resolve this contradiction, a high-frequency output converter topology has been proposed in 2021 by our research group. However, the reliability is the key problem of high-power converter, and the largest failure probability is the open circuit or short circuit of the power electronic device. This paper focused on the open circuit failure of high output frequency converter, and the failure diagnosis method is analyzed in detail then a redundant failure protection method is proposed. The proposed failure detection method is verified by simulation.