Design and Cogging Torque Optimization of Outer-Rotor Permanent Magnet Synchronous Motor

Outer-rotor permanent magnet synchronous motors (OPMSM) have the advantages of low heat generation, light weight and energy saving and high efficiency, and nowadays the research on OPMSM is becoming more and more extensive. However, PMSM have inherent cogging torque, which can cause torque fluctuation of the motor, causing the motor to vibrate and make noise. Therefore, it is of great importance to adopt a significant method to suppress the cogging torque. An OPMSM is designed in this paper, and the influence factors of its cogging torque are analyzed. In order to weaken the cogging torque, a cogging torque optimization method based on response surface model and MOGA is proposed for the OPMSM. The method selects the pole-arc coefficient, rotor inclined pole angle and stator slot width as the variables, and adopts the Latin hypercube sampling method to extract the sample points, and then uses the Kriging model to establish the response surface, and finally optimizes the input variables based on MOGA, and obtains the optimized candidate points. The optimized motor is comprehensively evaluated for cogging torque, back electromotive force (EMF) and load torque. The simulation results verify the effectiveness of the motor structure and optimized design.