Design And Research Of Permanent Magnet Synchronous Motor For Electric Vehicle

Nowadays,the problem of environmental pollution is becoming more and more serious,and the development of new energy has been paid more and more attention.Electric vehicles are strongly supported by the government for their advantages of energy saving,high-efficiency and zero emission.Permanent magnet synchronous motor is favored by the electric vehicle industry because of its high efficiency,high reliability and wide speed range.In this paper,the key technology of permanent magnet synchronous motor used in electric vehicle is studied according to the characteristics of the vehicle.A permanent magnet synchronous motor(PMSM)has been developed.The detailed work is as follows:In the first chapter,the development of electric vehicles and related research at home and abroad are introduced firstly,and the significance and necessity of developing electric vehicles and electric motors for electric vehicles are explained.In the second chapter,three key technologies of electric vehicle are introduced,and the types of motor used in electric vehicles are compared and analyzed;The motor type of the designed electric vehicle is determined to be PMSM;The rotor magnetic circuit of PMSM is built in structure;The mathematical model of PMSM is given.By studying the structure of PMSM,the main dimensions of PMSM are determined and the electromagnetic design parameters are calculated.In the third chapter,the basic theory of electromagnetic field and finite element method in motor is introduced.Based on the finite element software Ansoft Maxwell,the model of PMSM is established and the main technical parameters are calculated;Based on the finite element theory and the superposition idea of magnetic field and electromotive force,the method of solving the no-load counter EMF of the PMSM stator skewed slot is given on the Maxwell 2D module.In this chapter,the cogging torque of PMSM is deeply studied and analyzed,and an effective method to weaken cogging torque is put forward.In the fourth chapter,the field-weakening performance of PMSM for electric vehicle is studied,and the principle and method of field-weakening are introduced.The influence of the change of the motor-related structure on the field-weakening performance was studied by means of Toolkit which is based on Ansoft Maxwell platform developed by ANSYS.The MAP diagram of the efficiency,the d-axis current,the q-axis current,the winding loss and core loss of PMSM under different operating conditions are analyzed and calculated.In the fifth chapter,an electric vehicle PMSM prototype with rated power of 60kW and rated speed of 1600rpm is developed according to the previous research results.The performance test results of the prototype coincide with the results of finite element analysis.The performance of the designed prototype meets the design requirements,and the accuracy and feasibility of the analysis and design method are verified.