多物理场仿真开关磁阻电机定子的径向电磁振动

由于双凸极结构及磁饱和特性,开关磁阻电机较它型电机有较大的径向振动.通过多物理场仿真方法,开展定子壳体径向电磁振动耦合仿真.先通过二维电磁场有限元,分别在三相和六相工作模式下,计算额定转速下电机各定子齿所受径向电磁力密度的时程.再利用定子振动特征方程,进行了定子的模态分析.最后,将电磁力密度施加到相应定子齿作为外部激励,通过瞬态结构场分析获得了定子壳体的整体变形,以及关键节点加速度在时域和频域的振动特性.结果表明,在三相模式下,正方变形模态是壳体的典型振型;在六相模式下,椭圆变形是壳体振动的典型振型.正方变形时的加速度幅值要小于椭圆变形.该工作能从振动方面指导开关磁阻电机工作模式的选择和优化.

RADIAL VIBRATION SIMULATION OF THE STATOR IN SWITCHED RELUCTANCE MOTOR BY MULTIPHYSICS METHOD

The radial vibration of a switched reluctance motor (SRM) is more prominent than other type of motors, due to its inherent double salient structure and magnetic saturation. In this paper, the radial magnetic vibration coupling analysis was carried out by means of multiphysics simulations. Firstly, when the motor runs in three- and six-phase modes, the time history of radial magnetic force density in each stator teeth at rated speed was simulated by 2D electromagnetic finite element method (FEM), respectively. Then, natural frequencies and modes were obtained by solving the characteristic equation of the stator. Finally, the magnetic force density was applied onto the stator tooth as an external excitation, and the deformation of the whole stator was solved by 3D structure transient analysis. The accelerations of intermediate nodes on the outerwall of the stator were analyzed both in time and frequency domains. The results show that square deformation is the dominant mode under the three-phase excitation and elliptical deformation is the dominant mode under the six-phase excitation. The acceleration amplitude of square deformation is smaller than that of elliptical one.