永磁同步电机磁钢涡流损耗模型及其衡量指标

Eddy-current loss model and index for magnets of permanent magnet synchronous motors

针对高功率密度永磁同步电机在高转速下,所存在的较为严重的转子磁钢涡流损耗及其失磁风险问题,采用涡流场理论及麦克斯韦方程提出一种改进型的磁钢涡流损耗数学模型,可以对表贴式永磁同步电机涡流损耗进行定量分析;并根据分析结论,总结了与涡流损耗相关的关键影响因素,提出衡量磁钢内涡流损耗的技术指标。利用该指标可以指导电机极槽配合、磁钢厚度等电机设计关键参数的设计。同时有限元分析结果表明,该指标也可以用于内置式永磁电机磁钢涡流损耗的衡量;利用此指标对几种极槽配合电机结构进行了对比研究,验证了涡流损耗指标的有效性。

In allusion to the problem of demagnetization of magnets and the large eddy-current loss at high speed region for the high power density permanent magnet synchronous motors （PMSMs）, the paper im- plements detailed systematic research on the mechanism and key factors of eddy-current losses in rotor magnets of high power-density PMSMs. Firstly, it established quantitative mathematic model of eddy-cur- rent losses for surface-mounted PMSM based on eddy current field model and Maxwell equations. Then, an index was put forward to weigh the key factors relevant to the eddy-current losses in magnets, which can provide good reference for the motor design of pole-slot combination, size of magnets and other impor- tant parameters. Meanwhile, regular pattern and influential factors of eddy-current loss were researched by mean of finite element analysis （FEA） method. Comparisons with several types of slot-pole combina- tion structures were proposed, which proves the effectiveness of the index.