Abstract: To address the problem of the long detection time of the current detection method during the open

circuit fault diagnosis of inverter insulated gate bipolar transistor（IGBT）of the permanent magnet synchronous

motor（PMSM）drive system，an error current polarity method based on model predictive current control（MPCC）

was investigated. By combining the variation of the cost function in MPCC with the current detection method，the

fault detection time can be effectively reduced. However，the MPCC is susceptible to changes in motor parameters，the load torque and speed changes may lead to changes or mismatches in the motor parameters，which in turn affect the output of the cost function and lead to misdiagnosis. To address the issue，the fault detection indicators were normalized and a counting method was added to the MPCC-based error current polarity method to further improve the robustness of fault diagnosis.

      Key words: motor drive system；insulated gate bipolar transistor（IGBT）open circuit fault；fault detection and

localization；model predictive current control（MPCC）