Permanent Magnet Synchronous Motors have the advantages of small fooprint, high operating efficiency, strong power and large starting torque, and are widely used in high-tech industries such as aerospace, navigation and automobiles. However, due to the permanent magnet materials used in the permanent magnets, demagnetization failures are pro to occur in the case of High temperature and short-circuit between turns, which greatly effects the stable operation of the Permanent Magnet Synchronous Motor.