Research On Electromagnetic Performance And Temperature Field Of An Axial Flux Permanent Magnet Motor For Vehicle

The permanent magnet synchronous motor currently used in the ISG system is mainly a radial flux permanent magnet synchronous motor,but there are problems of low power density,low efficiency,and large space size.This article is based on the performance indicators and use requirements of the ISG motor.The preliminary design of the axial flux permanent magnet motor of the ISG system determined the basic structural parameters and electromagnetic parameters of the motor;then,taking the designed motor as the research object,the analytical model of the motor was improved,and the axial magnetic of the designed motor was explored.The change law of tension and electromagnetic torque,thereby optimizing the structural parameters and electromagnetic parameters of the motor;then the loss analysis of the designed motor is carried out,focusing on the eddy current loss of the designed motor,and the motor parameters are further optimized;finally,the loss study On the basis of,the cooling scheme of the designed motor was selected reasonably,and the temperature field of the motor was studied by establishing a temperature field model.The results showed that the temperature rise of the designed motor was reasonable and could meet the performance requirements of the ISG system.First of all,the overall design scheme of the research on the axial flux permanent magnet motor of the ISG system is given.Based on the comparative analysis of the traditional radial flux permanent magnet motor and the axial flux permanent magnet motor,according to the special working conditions of the ISG And performance requirements,determine the axial flux permanent magnet motor suitable for ISG system.Then,on the basis of meeting the requirements of technical indicators,the structural parameters and electromagnetic parameters of the motor are preliminarily designed,and the magnetic circuit parameters,winding current density,thermal load and field weakening performance of the axial flux permanent magnet motor are analyzed.Contribute to the study of electromagnetic performance of the designed motor.Secondly,in order to describe the air gap magnetic field distribution of the motor more accurately and to facilitate the optimal design of the motor,a three-dimensional finite element model of the motor designed in this paper,an analytical model based on the equivalent surface current method and an analytical model considering the stator cogging effect are established,And improved the analytical model considering the cogging effect by equating the magnetic poles as electrofluid elements.Then the electromagnetic field performance of the air gap flux density,edge effect and no-load electromotive force of the axial flux permanent magnet motor are analyzed respectively.The results show that the improved analytical model and the three-dimensional finite element simulation results have relatively small errors,which can accurately reflect the designed motor The magnetic field distribution.At the same time,the changes of electromagnetic torque and axial magnetic tension of the designed motor are explored,and the structural parameters and electromagnetic parameters of the motor are optimized.Thirdly,the core loss and winding copper loss of the motor designed in this paper in the electric state and power generation state are studied,and the results show that the designed motor can effectively reduce the loss and improve the efficiency of the motor.Then the eddy current loss of the designed motor is studied emphatically,and the influence of stator core material and stator cogging groove shape on eddy current loss is analyzed.Based on the above analysis,measures to suppress the motor loss are given,and the motor parameters are further optimized.Finally,on the basis of the loss study,the temperature field and pressure field simulations of two cooling water channel schemes are given,so that the cooling water channel scheme of the motor is reasonably selected.By calculating the thermal conductivity,heat source and loading method of the designed motor,the temperature field model of the motor is established,and the temperature rise analysis of the main components of the motor under the electric condition and the power generation condition is completed.The results show that the temperature rise of the motor designed in this paper is reasonable and meets the requirements of the ISG system.