中文摘要：

提出一种电动汽车用双层永磁体内置式永磁同步电机（interior permanent magnet synchronous machine,IPMSM）,分析其基本电磁关系,进行优化分析。采用有限元分析软件建立电机结构模型,分析单边气隙长度不同时气隙磁密及谐波畸变率变化规律;研究了不同定子槽口宽度下电机齿槽转矩的变化趋势;通过改变第二层永磁体两侧隔磁桥间距R_（ib）及第一层永磁体中间隔磁桥与转轴距离,获得电机输出转矩与转矩纹波的变化规律;分析双层永磁体尺寸变化时的电机效率,得到最优永磁体尺寸参数。样机试验表明：实测值与仿真值基本吻合,验证了样机设计的合理性。

英文摘要：

An interior permanent magnet synchronous machine （IPMSM） with double-layer permanent magnets （PMs） used in electric vehicles （EVs） is proposed, of which the basic electromagnetic relation- ship are analyzed, and an optimization analysis is conducted. The motor structure model was established by using finite element analysis software, the air-gap flux density and harmonic distortion rate changing rule were analyzed when unilateral air-gap is at different lengths. The variation tendency of cogging torque was investigated by the method of optimizing slot-opening width of the stator. The output torque and torque ripple are obtained by changing Rib （the second layer on both sides of the PM separation bridge spacing interval） and 02 （ the first layer of PM bridge between the shaft）. The efficiency was analyzed when changing the size of the double-layer PM, and the optimal size of PM parameters was obtained. The corresponding experimental results show that the measured and simulation values basically match, which verifies the rationality of the designed prototype machine.