THE METHOD FOR REDUCING COGGING TORQUE BY SUITABLE SELECTION OF POLE-ARC COEFFICIENT IN SOLID-ROTOR PM SYNCHRONOUS MOTORS

Cogging torque is one of the main concerns of permanent magnet motor. In this paper, to reduce cogging torque in solid-rotor permanent magnet synchronous motors, an analytical method, which was based on energy method and Fourier expansion, was proposed to obtain the expression of cogging torque, which can express its relation with design parameters. Being based on the expression, the effect of pole arc-coefficient on cogging torque is studied. The method for reducing cogging torque by suitable selection of pole arc coefficient was proposed. The most suitable pole-arc coefficient can be determined according to the combination of pole number and stator slot number. The validity of the proposed method was verified by finite element analysis.