Research On High Power Density Permanent Magnet Motor And Its Control Technology For Electric Vehicle

The rapid growth of traditional car ownership has brought great challenges to environmental management and energy security in China.The development of electric vehicles is an effective way to solve these problems.Permanent magnet synchronous motor has the advantages of simple structure,small volume,light weight,low loss,high power density and wide speed range,and has broad prospects for development in electric vehicle drive motor.Based on the design parameters of the existing permanent magnet synchronous motor,this paper studies the performance requirements of the electric torque and the rotational speed of the electric vehicle under the complicated working condition,and determines the basic parameters of the permanent magnet synchronous motor.By analyzing the working principle and structure of permanent magnet synchronous motor,a high power density permanent magnet synchronous motor for electric vehicle is designed.According to the analysis of the performance of the motor with different magnetic circuit structure,the structure of the built-in "V" type motor is put forward.The whole structure of the motor and the main structural parameters of the permanent magnet rotor are designed and calculated.The vector star graph method is used to determine the armature double winding Short circuit in the form of embedded,designed 8 8-slot integer slot winding stator;completed the electric vehicle permanent magnet synchronous motor design.The two-dimensional simulation model of permanent magnet synchronous motor was established by using Ansoft finite element analysis software,and the no-load and load simulation were carried out.The magnetic field diagram,air gap flux density distribution,no-load back electromotive force,cogging torque and motor core Loss and other waveforms,the simulation results show that the design of permanent magnet drive motor electromagnetic characteristics and output characteristics of good,high utilization of materials,less motor loss.By comparing the performance of the 2004 Prius electric vehicle drive motor and the permanent magnet synchronous motor,the design of permanent magnet synchronous motor for electric vehicle has certain advantages in terms of efficiency and power density.Based on the operation condition of electric vehicle,the vector control method of permanent magnet synchronous motor is designed.The simulation model of control system is established by Matlab / Simulink software.The torque,speed and dq axis current of the motor with load start and load change are simulated and analyzed.The results show that the designed permanent magnet synchronous motor for electric vehicle has good speed performance.