Open Circuit Fault Diagnosis and Fault Tolerance Control of PMSM Inverter Based on High Frequency Injection

Since the traditional fundamental frequency current method has low accuracy in diagnosing open-circuit faults when the permanent magnet synchronous motor (PMSM) is at low to medium speeds and with light or heavy loads, this paper proposes a high-frequency voltage injection method with strong interference resistance to diagnose open-circuit faults in PMSMs. The method takes the high frequency current amplitude as the fault marker, and the residual analysis is carried out by the joint health current observer, so as to construct the open-circuit fault localisation table, based on which fifteen different types of open-circuit faults can be accurately located, and then a three-phase, four-bridge faulttolerant system is designed to carry out fault-tolerant control for fifteen types of open-circuit faults in the table. Finally, by building a simulation model in MATLAB/Simulink software, it is verified that this method still has high diagnostic accuracy when the PMSM is in low and medium speed.