Design And Characteristic Research Of Permanent Magnet Synchronous Motor For New Energy Vehicle

With the aggravation of the world energy crisis,traditional vehicles will be severely hit,promoting the rise of new energy electric vehicles and gradually leading the development of future vehicles.Compared with other types of motors,permanent magnet synchronous motor(PMSM)has the advantages of high efficiency,strong overload capacity,high power density,wide speed range and low vibration and noise as the power source of new energy vehicles,which has attracted the attention of many automobile enterprises.Therefore,it is necessary to study PMSM in depth.This paper mainly studies the new energy drive motor from three aspects : motor structure design,structure optimization and torque characteristics analysis.The main research work includes the following aspects :(1)Firstly,based on the driving conditions of the new energy vehicle,the performance requirements of the driving motor under various working conditions are proposed.Referring to the vehicle parameters of a new energy vehicle,the key performance parameters of the motor such as rated power,torque and speed are calculated.Then considering the operation characteristics of the new energy drive motor,the appropriate type of drive motor is selected,and the main size of the motor is calculated by using the electromagnetic load prefetching method.Then the appropriate stator slot type is designed to reduce the torque ripple and improve the stability of the motor.According to the working principle of permanent magnet synchronous motor,the copper electromagnetic wire and double distributed winding are selected to weaken the air gap harmonics and improve the back EMF and flux density waveform sine.Finally,in order to improve the utilization rate of the permanent magnet and reduce the cost of the motor,the size range of the permanent magnet structure is analyzed and calculated.Considering the output performance and operation stability of the motor,the initial value of the air gap is set.Finally,the structural parameters and electromagnetic performance parameters of the motor are obtained.(2)Based on ANSYS/Maxwell 2D,the motor characteristics and gear torque characteristics of the PMSM under no-load,rated load and overload operating conditions were obtained.For motor parameters such as the electric potential and the torque ripple of irrationality,based on taguchi method is proposed of the permanent magnet drive motor multi-objective optimization method,choose four permanent magnet structure parameters as optimization variables,and the motor torque and back emf and loss as the optimization goal,parameters such as ultimate permanent magnet was determined by the motor performance scatter plot structure,the optimal parameters.Based on the optimized motor structure,the performance of the drive motor under low speed rated condition,low speed peak condition,high speed rated condition and high speed peak condition was analyzed.(3)In order to explore the harmonic weakening effect of the tooth,the rotor magnetic pole segmented oblique pole method was selected in this paper to study the harmonic weakening effect of the tooth,mainly including: Rotor pole section inclined pole method for motor racing Back Electromotive Force,the cogging torque,the average torque and torque ripple,the influence of the rotor pole section shift oblique pole of the selection of optimum shift Angle,summarized the rotor pole section inclined extremely weaken the harmonic,when the rotor is divided into n weakened segments order k the cogging torque,in addition to the n?k order integer times of cogging torque,The rest of the alveolar torque can be effectively reduced.(4)Firstly,the influence of stator rectangular auxiliary slot and rotor triangular auxiliary slot on the torque characteristics of the motor is studied.Then,the weakening effect of stator rectangular auxiliary slot and rotor triangular auxiliary slot on cogging torque is simulated and analyzed under the condition of single parameter variable,and the weakening law is summarized.Then,the effects of stator rectangular auxiliary slot and rotor triangular auxiliary slot on cogging torque,no-load Back Electromotive Force distortion rate and load torque are analyzed in the case of multiple variables.Finally,it is summarized that the cogging torque is weakened more obviously in the case of multiple variables of stator and rotor auxiliary slots.