A Novel Cogging Torque Reduction Method for Interior Type Permanent Magnet Motor

This paper presents a novel design method to reduce cogging torque of interior type permanent magnet (IPM) motor. In the design method, the optimal notches are put on the rotor pole face, which have an effect on variation of permanent magnet (PM) shape or residual flux density of PM. Through the space harmonics field analysis, the positions of notches are found and the optimal shapes of notches are determined by using finite element method (FEM). The validity of the proposed method is confirmed by experiments.