Optimal Design And Performance Study Of A Permanent Magnet Synchronous Motor With Novel Structure Rotor

In recent years,efficient hybrid electric propulsion vehicles have been gradually put into the market to solve the existing energy crisis and environmental pollution problems.The introduction of electric vehicle requires higher performance of motor.For example,it requires motor miniaturization,light weight and high efficiency.Among all kinds of permanent magnet synchronous motors,built-in permanent magnet synchronous motor(IPMSM)is mainly used in driving motors and hybrid propulsion vehicles.How to improve its performance is the development trend of current research.The design of the IPMSM has a lot of previous experience to emulate,but there are still many issues that need to be addressed.By changing the rotor structure,the power density can be further improved under the same volume,so as to improve the performance and characteristics of the motor.This paper presents a new type of permanent magnet synchronous motor with rotor structure.On the premise of the same amount of rotor permanent magnet material,the stepped permanent magnet structure adopted by this structure can effectively improve the air-gap magnetic density waveform,thus improving the motor performance.In order to obtain the design parameters of the stepped permanent magnet structure,the magnetic circuit model of the new-type rotor structure motor was firstly established in this paper,and the initial design parameters of the rotor permanent magnet were obtained by taking the air-gap magnetic fundamental wave and harmonic distortion rate as the objective functions.In order to find better optimization method for motor design optimization,this paper first introduced multi-scale quantum harmonic oscillator optimization algorithm(MQHOA)to motor design optimization problem.Using the mathematical model of the motor as the objective function,the primary structure parameters of the motor is obtained.In order to validate the advantage and feasibility of MQHOA algorithm,this paper compared the GA and SA optimization algorithm,the contrast results show that the performance of MQHOA slightly better than genetic algorithm and simulated annealing algorithm.In order to make up the motor model error,Taguchi method is used to optimize the above results.Taguchi method is different from other local optimization design methods in that it can optimize the design of multiple targets.By establishing the orthogonal table of experiments,it can obtain the optimal combination of various design parameters in the multi-objective optimization design with the least number of experiments.It is a commonly used local search optimization method.In order to further study the performance of permanent magnet motor,this paper then used taguchi method to optimize the initial design parameters,and obtained the final size structureoptimization parameters of the motor.Finally,the performance of the stepped permanent magnet motor is compared with that of the traditional permanent magnet structure,and its correctness is verified by finite element simulation software.The results show that the new structure can improve the sine degree and fundamental amplitude of the air-gap magnetic density waveform and reduce the harmonic distortion rate.