Design And Running Performance Simulation Of PM Brushless Motor For EV

The electric vehicle is an inevitale choice of transportion faced with dual pressures ofenergy and environment, and an important development direction of anto industry. Therare-earth permanent magnet brushless motor has the characteristics of high efficiency,highpower density and is particularly suitable for electric vehicle drive. The interior permanentmagnet magnetic circuit structure is widely used in permanent magnet brushless motor forelectric vehicle, because it has the characteristic of high mechanical strength and is suitablefor flux-weaking control, the permanent magnet isn’t easy to be demagnetized.In this paper, an electric vehicle of a company is the application objects, power systemmatch is researched, simulation model is established used of MATLAB/Simulink platformbased on vehicle dynamics analysis. the drive motor parameters is determined based onrequirements of electric vehicle acceleration performance,maximum speed,maximumgradeability. An interior permanent magnet brushless motor is designed used of Ansoftsoftware, the influence of air gap size,winding turns,and thickness of the permanent magneton the motor efficiency,the ratio of toqure to current is analysed, the efficiency model isestablished to calculate the driving range by condition method and uniform method.Aimed at the problems of electric drive system that low speed and light load runningstate reduce system efficiency. winding switching technology and dual-motor drive toimprove is proposed. Simulation results show that the winding switching can significantlyimprove the electric drive system efficiency and reduce the thermal load of high-speed zone,and also improve the low-speed zone performance, the drive range of condition method anduniform method are improved. Dual-motor centralized drive can improve system efficiencyby shutting down one motor at light load, the drive range of uniform method is improved.Because the rated power of single motor decreases, the high efficiency area is narroweddown, so the drive range of condition method is reduced, but winding swithcing can mendit. The dual-motor distributed drive can significantly improve the drive range of conditionmethod and uniform method,due to the advantages of structure.This paper aimed at improving the drive range of electric vehicle, focused on theelectric drive system low-speed and light load efficiency improvement. The advantages ofwinding switching and dual-motor drive is analysed theoretically and simulated,the analysismethod and conclusion has guiding significance.