Demagnetization diagnosis of permanent magnet synchronous motor by using continuous wavelet transform

The permanent magnet synchronous motor which has permanent magnet instead of field winding in the rotor has especially higher efficiency and torque per weight than other types of motor. When the irreversible demagnetization is occurred, users can be exposed to high risk of accident by the fault operation of motor. Because of this, the irreversible demagnetization of permanent magnet should be detected by using any kinds of method to reduce the risk of accident. In this study, the demagnetization diagnosis method based on the result at the rated operating condition simulation is proposed for the permanent magnet synchronous motor. The input current waveforms are analyzed by using the continuous wavelet transform to detect demagnetized poles in the model.