Design And Analysis Of Low Torque Ripple Continuous-pole Permanent Magnet Synchronous Moto

Permanent magnet synchronous motors(PMSM)are widely used in various fields of daily life due to their simple structure,reliable operation,small size,lightweight,low loss,and high efficiency.Based on maintaining the advantages of PMSM,consequentpole permanent magnet synchronous motor(CPMSM)improves the utilization rate of permanent magnet(PM)and reduces the motor cost,which makes it highly concerned.However,due to the special rotor structure of CPMSM,there are a large number of harmonics in the rotor magnetomotive force(MMF),which increases the torque ripple.reduce the torque ripple of CPMSM,this paper designs the motor from two aspects of rotor pole structure and stator structure.The magnetic pole structure of CPMSM is asymmetric,resulting in high harmonic content of no-load air gap flux density and large torque ripple.To solve this problem,a hybrid consequent pole(HCP)magnetic pole structure with auxiliary PM on one side of the iron pole is proposed in this paper.This structure improves the problem of asymmetric magnetic pole structure of CPMSM,and then reduces the harmonic content of no-load air gap magnetic density.To match the parameters in the HCP magnetic pole structure,this paper optimizes it based on the Taguchi method.Furthermore,the influence rule and the relative importance of each optimization variable on the optimization goal are obtained by the average value analysis,significance analysis,and variance analysis.According to the above analysis results,the optimized hybrid consequent-pole permanent magnet(HCPMSM)motor is obtained.Finally,through the comparative analysis of the electromagnetic performance of the CPMSM and the HCPMSM,it is proved that the proposed magnetic pole structure is effective in reducing torque ripple.The asymmetric winding structure of fractional slot CPMSM leads to a large number of even harmonics in the stator MMF.The even harmonics in the stator and rotor MMF interact to increase the torque ripple.To solve this problem,this paper proposes modular stator structure(MS)and multi-layer winding modular stator structure(MW)to reduce the distribution coefficient of even harmonics in motor stator MMF,and then reduce the amplitude of even harmonics in stator MMF.To achieve a better comprehensive performance of the motor,the rotor structure of traditional winding CPMSM,modular stator structure consequent-pole permanent magnet synchronous motor(MS-CPMSM),and multi-layer winding modular stator structure consequent-pole permanent magnet synchronous motor(MW-CPMSM)are optimized with the optimization goal of high torque average value and low torque ripple.Finally,through the comparative analysis of the electromagnetic performance of CPMSM,MSCPMSM,and MW-CPMSM,the effectiveness of the proposed structure in reducing torque ripple is proved.