陈亮亮 祝长生 乔晓利 伍家驹

关键词：表贴式永磁同步电机;碳纤维护套;解析解;强度分析;应力函数法

DOI：10.15938/j.emc.2019.06.000

中图分类号文献标志码：A 文章编号：1007 -449X（2019）06 -0000 -00

Abstract：As for the problem of no analytical solution of rotor strength for high speed segmented surface mounted permanent magnet synchronous machine （SPMSM） with a carbon fiber sleeve， the analytical solution of rotor strength was proposed based on the plane stress model. The displacement method and stress potential method in polar coordinates were employed to deduce the analytical solution， and the influences of different densities and coefficients of thermal expansion of permanent magnets and pole fillers were taken into account. Then the effectiveness of the analytical solution was validated by finite element method. The effects of design parameters on rotor strength， such as rotational speed， thickness of carbon fiber sleeve and interference fit between the carbon fiber sleeve and the permanent magnet， were further investigated based on the analytical solution proposed. It is shown that the results calculated by the analytical solution and finite element method are in good agreement with each other. The analytical solution proposed can predict the stress distribution of the high speed segmented SPMSM′s rotor with a carbon fiber sleeve， considering the effects of difference in density and coefficient of thermal expansion between permanent magnets and pole fillers.

Keywords：surface mounted permanent magnet synchronous machine （SPMSM）; carbon fiber sleeve; analytical solution; strength analysis; stress potential method

0 引 言

高速表貼式永磁同步电机（surfacemounted permanent magnet synchronous motor，SPMSM）具有结构简单、可靠性强、效率高、功率密度高等优点，已得到了广泛的应用[1-2]。稀土永磁材料因其高剩磁、高矫顽力及高磁能积等特点而被广泛应用于永磁电机[3]。在高速SPMSM中永磁体既可加工成整体结构也可制作成分块结构。在整体结构中，永磁体常加工成圆柱型或圆筒型;在分块结构中永磁体常加工成瓦片型，磁极间采用非磁性材料填充，填充块能保证转子结构的整体性并起阻尼作用，同时也有助于永磁体的固定。整体永磁结构具有结构简单，易于加工，机械强度高等优点，但永磁材料的利用率较低。分块永磁体结构提高了永磁材料的利用率，还可以通过选取合适的极弧系数来优化电机气隙磁场，其缺点是加工工艺较复杂，机械强度较低。

由于稀土永磁材料的抗压强度较大而抗拉强度很小，容易被电机高速运行时产生的巨大离心力所破坏，因此需要采用非导磁保护套对永磁体进行保护。目前，非导磁保护套主要有高强度复合材料护套及非导磁金属护套2类。常用的高强度复合材料有碳纤维和玻璃纤维，常用的非导磁金属材料则有钛合金及高强度合金钢。与非导磁金属护套相比，高强度复合材料护套具有强度高、质量轻、无高频涡流损耗等优点，但复合材料是热的不良导体，不利于永磁体的散热[4-6]。……