Demagnetization Fault Diagnosis of Permanent Magnet Synchronous Motor with Inductance Disturbance

To address the problem of demagnetization fault diagnosis of permanent magnet synchronous motor (PMSM) under inductance change, a demagnetization fault detection method based on an adaptive observer is proposed. First, the mathematical model of the demagnetization fault of PMSM in a synchronous rotating coordinate system is established, and the inductance disturbance is analyzed separately. Then, considering the different characteristics of the flux linkage fault and inductance disturbance, a new adaptive observer is proposed. Two adaptive laws are designed to ensure the accuracy of fault diagnosis and to eliminate the influence of inductance disturbance, thus achieving the robust diagnosis of demagnetization fault.