Online Rotor Fault Diagnosis of Permanent Magnet Synchronous Motors Based on Stator Tooth Flux

Demagnetization and eccentricity are common rotor faults of permanent magnet synchronous motors, which are important factors affecting the reliability of the motor and the whole drive system. Therefore, monitoring and diagnosing these faults online is important. A mathematical model of stator tooth flux under demagnetization and eccentricity faults is established to solve this problem and analyze the influence of demagnetization and eccentricity on the spatiotemporal distribution of stator tooth flux. Moreover, a method that extracts rotor fault characteristics and formulates the corresponding fault diagnosis is proposed. The proposed diagnosis method is analyzed and verified through simulation and experimentation, and results show that the proposed method can efficiently diagnose and differentiate between demagnetization and eccentricity faults. The proposed method can provide an important basis for the operation and maintenance of the motor, assist in the reduction of loss due to faults, and improve the reliability of the motor and the entire system.