Design And Research Of Permanent Magnet Synchronous Machine For Electric Vehicle Application

With global energy and environment issue becoming increasingly severe, thedevelopment of new energy vehicle is imperative. Because of the small volume, highefficiency, high power density and low loss and other advantages, the permanent magnetsynchronous motors (PMSM) is widely concerned in electric vehicle drive motor products. Asthe core component of electric vehicle drive system, its PMSM directly determine the vehicleperformance. Therefore, it is significant and practical in application to elaborately designexcellent performance PMSM. The frame design of PMSM was systematically studied in thispaper, including design method, performance computation, finite element analysis, parametricanalysis and optimal performance, etc.Firstly, the background significance of this paper was expounded and the development ofPMSM at home and abroad was analyzed. The working principle, structure characteristics,steady state performance of PMSM was introduced.Secondly, a30kW PMSM was designed as an example，the process of design and keytechnology was analyzed in detail. The performance of PMSM was calculated by using theRMxprt and Ansys Maxwell2D. The various performance of no load and full load was deeplyresearched and the result was satisfactory. The motor was parametric analyzed and someuseful conclusions were obtained. The performance of interior-type and surface-mountedPMSM was compared.Then, three measures of cogging torque reduction methods,(the optimal notches put onthe rotor pole face, pole width modulation, the magnetic poles shift) was reserched based onthe cogging torque analytical formula of energy method. The expression of correspondingoptimization parameters of each methods was given. The optimization effect of the optimalnotches put on the rotor pole face was verified by the10poles and12slots PMSM. Themethods of pole width modulation and the magnetic poles shift was applied to the PMSMwhich was designed and optimized in this paper, The result showed that the cogging torqueand the torque ripple can be greatly restrained by the above two methods, and theperformance of original motor will not be affected. In addition, the weight of permanentmagnet can be reduced by the pole width modulation. Finally, the different region of stator teeth and yoke of flux density component andmagnetic track was obtained by finite element simulation with the model of optimized PMSM.The corresponding position of magneting manner was analyzed. Based on the Bertotti ironloss separate model, the iron loss density of each region was calculated and distribution of thestator iron loss was analyzed by dividing the stator into different areas. The calculation of thePMSM stator iron loss and the result of the finite element was compared.