System Modeling And Performance Analysis Of Hybrid Permanent Magnet Motor With Asymmetric Rotor

In recent years,new energy vehicles with the advantages of energy conservation,environmental protection,safety and reliability have gradually become a new direction for the development of the automotive industry in the future.Rare-earth permanent magnet motor has become one of the preferred motor types for new energy vehicles because of its advantages of high power density,small volume and low noise.However,As the price of rare earth materials fluctuates greatly and the supply is unstable,the production cost of this kind of motor increases,which also adds uncertain factors to the large-scale promotion and application of new energy vehicles.In order to reduce the amount of rare earth permanent magnet materials in permanent magnet synchronous motor and improve the utilization rate of permanent magnet materials.A rare earth asymmetric rotor hybrid permanent magnet（abbreviated as AR-HPM）motor is proposed in this paper.Based on the analysis methods of magnetic circuit and circuit,nonlinear electromagnetic field and field-circuit dynamic coupling,the performance of AR-HPM motor is analyzed.The main research contents of this paper include the following aspects:Firstly,the development prospect of new energy vehicles and the tight supply and demand situation of rare earth resources are summarized.The research status of non-rare earth motors,non-rare earth ferrite motors and rare earth hybrid permanent magnet motors are summarized.On this basis,an asymmetric rotor hybrid permanent magnet（AR-HPM）motor is proposed.The structure and operation principle of the motor are introduced,and the mathematical model of the motor is given.Secondly,the finite element model of AR-HPM motor is established.The basic electromagnetic properties of the motor,such as magnetic field distribution,no-load characteristics,torque characteristics and inductance characteristics,are analyzed by the finite element method based on electromagnetic field theory.Thirdly,based on MATLAB Simulink platform,according to the mathematical model of the motor,the electromagnetic parameters calculated by finite element method are imported offline to establish the mathematical model of AR-HPM motor.Combined with MTPA control and field weakening control strategy,the drive control system model of AR-HPM motor in the full speed region is built.The dynamic performance of AR-HPM motor under different operating conditions is analyzed.Fourthly,the magnetic field-circuit multi-physical field coupling model of AR-HPM motor is established,and the motor performance under variable working conditions is analyzed through field-circuit coupling simulation,and the results are compared with those of Maxwell and MATLAB.Secondly,with the aid of field-circuit dynamic coupling analysis,the key structural parameters of the motor are optimized with the average efficiency and torque performance as the optimization objectives.Fifthly,the prototype of AR-HPM motor was manufactured,and the no-load back EMF and steady torque performance of the motor were verified by experiments,which were compared with the simulation results,and the rationality of the motor structure and the accuracy of the analysis method were verified.