Study in the post-assembly magnetization method of permanent magnet motors

Abstract

This paper studies two post-assembly magnetization methods for permanent magnet motors. One is stator winding magnetization method (SWMM) for ferrite magnets. The other is magnetizing fixture magnetization method (MFMM) for magnets having large coercive force like NdFeB magnets. They are applied to three types of permanent magnet motors: SPM type of BLDC motor, LSPM type motor and IPM type of BLDC motor. In case of line start permanent magnet motors (LSPM), the eddy current produced in the rotor bars seriously disturbs magnetizing. Therefore, the magnetization processes are analyzed by using the time stepping finite element method. As a result, it is clarified that the SWMM is proper for the SPM type motor using ferrite magnets and the MFMM is proper for the LSPM and IPM type motors using NdFeB magnets.