Demagnetization is a common fault of double-sided permanent magnet linear synchronous motor (DPMLSM) with high speed and high current density. In this paper, a mathematical model of demagnetization fault for moving magnet type DPMLSM is established. Then the factors affecting the loss of DPMLSM are analyzed. Through the coupling analysis of electric field and thermal field, combined with the layered model of permanent magnet, the temperature field distribution of the motor is calculated. The permanent magnet area which is most affected by the temperature is determined. And the performance of DPMLSM with demagnetization faults are analyzed.

DPMLSM， demagnetization， loss， thermal analyze， performance analyze.