Design And Multi-Objective Optimization Of High Power Density Permanent Magnet Synchronous Motor

Permanent magnet synchronous motor(PMSM)is widely used in various industrial fields due to its high power density and good speed regulation performance.With the increasing application of PMSM,robot joint drive,aerospace and other special applications not only require PMSM to have higher power density,but also put forward higher requirements for its comprehensive performance.Multi-objective optimization is an effective method to improve the comprehensive performance of motor."Algorithm model + algorithm optimization" is a common multi-objective optimization method of motor,which has the characteristics of simple operation and good optimization effect.However,in the practical application process,the method still has the problems of long optimization process and low optimization efficiency.In this paper,a high power density PMSM is designed with the aim of rated power density no less than 2 k W/kg.Based on the orthogonal experimental method,the sensitivity analysis of the rotor structure parameters that affect the output performance of the PMSM is carried out.Then a new multi-objective optimization method is proposed,and the motor designed in this paper is optimized based on the new method.Finally,based on the experimental method,the correctness of the design process and the effectiveness of the optimization method proposed in this paper are verified.The main work of this paper is as follows:1.A high power density PMSM with a rated output power of 5 k W and a power density of no less than 2 k W/kg is designed,and the torque ripple of the motor is reduced by adopting the segmented rotor technology and rotor pole cutting technology.2.The influence of rotor structure parameters on the PMSM output performance is studied.Based on the orthogonal experimental method,the sensitivity analysis of the rotor structure parameters which affect the output power and torque ripple of the PMSM is carried out,and the influence trend of the change of the rotor structure parameters on the output power and torque ripple of the PMSM is studied through the "index factor" diagrams.3.Based on the multi-objective optimization method of "orthogonal experiment +algorithm model + algorithm optimization",a new multi-objective optimization method of motor is proposed: firstly,the structural parameters to be optimized are divided into general structural parameters and important structural parameters based on the orthogonal experiment method;secondly,the "index factor" diagrams of general structural parameters of motor is obtained based on the range analysis method,and the general structural parameters of the motor are optimized based on those “index factor” diagrams;in the third step,the important structural parameters of the motor are grouped,and the important structural parameters of each group are iteratively optimized based on the optimization method of "algorithm model + algorithm optimization" until the optimization end condition is met.4.This paper completed the performance test of the motor prototype.By testing the output power,torque ripple and steady-state temperature rise of the motor prototype,the correctness of the motor design process and the effectiveness of the multiobjective optimization method proposed in this paper are verified.