广域高效车用轴向磁通永磁同步电机的设计分析

Design and analysis of wide-area and high-efficiency axial flux permanent magnet synchronous machine for EVs

针对车用驱动电机转矩和转速多变,运行范围宽广,需要提升电机在全域运行范围的高效率能量转换的问题,提出以高效率区间占比为设计目标的车用轴向磁通永磁电机设计方法。提出了考虑PWM供电影响的电机铁耗工程计算方法。基于等效磁网络法和集总参数热网络法构建了轴向磁通永磁同步电机的快速磁-热耦合设计模型,提高了车用轴向磁通永磁同步电机的设计精度。基于磁热耦合模型,分析了极弧系数、每槽导体数、气隙长度、永磁体尺寸、定子槽型尺寸等关键设计参数对车用轴向磁通永磁同步电机高效率区间占比的影响。设计并制造了样机一台,开展了电机效率和温升测试实验,获取了全域运行范围内的电机效率及电压分布,测试结果验证了磁热耦合模型和设计结果的有效性。

The electric vehicles(EVs)have a wide operation region,and the driving torque and speed of the electric machine vary.In order to extend the endurance of the EVs,the high efficiency of the energy conversion of the driving motor in the whole speed-torque region should be improved.The proportion of high-efficiency areas to the whole operation area(PHTW)was proposed as a design objective of the axial flux permanent magnet synchronous machine for EVs.An engineering calculation method of core loss calculation method considering the PWM influence was presented.Based on equivalent magnetic network method and lumped parameter thermal network method,a fast magnetic-thermal coupling design model of axial flux permanent magnet synchronous machine(AFPMSM)was constructed,which improves the design accuracy of AFPMSM for EVs.Based on the magnetic-thermal coupling model,the influence of pole-arc coefficient,number of conductors per slot,air gap length,permanent magnet size and stator slot size on the PHTW of AFPMSM were analyzed.A prototype was designed and manufactured,and the test experiments of motor efficiency and temperature rise were carried out.The distribution of motor efficiency and voltage in the whole operation range were obtained.The validity of the magnetic-thermal coupling model and the design results are verified by the test results.