无轴承永磁同步电机有限元分析

Finite Element Analysis for Bearingless Permanent Magnet-type Synchronous Motors

无轴承永磁电机径向悬浮力与电机绕组结构、永磁体厚度及悬浮力绕组中电流等存在着复杂关系,研究这些关系对电机优化设计具有重要参考价值。该文在介绍了无轴承永磁同步电机径向悬浮力产生原理基础上,推导了径向悬浮力数学模型。用有限元分析和计算方法,讨论了无轴承永磁同步电机在定子绕组相应等效电流作用下,改变径向悬浮力绕组中的电流,电机气隙磁路分布状况;在电机气隙不变,改变永磁体厚度,计算和分析了径向悬浮力与永磁体厚度之间的关系;在电机转矩绕组极对数pM=2不变的情况下,对径向悬浮力绕组采用一对极pB=1和三对极pB=2方式绕制,计算和比较产生的径向悬浮力和麦克斯韦力大小。对pM=2,pB=3的实验样机,在静态悬浮状态下,测试了径向悬浮力和径向悬浮力绕组电流之间的关系,实验结论验证了ANSYS软件计算结果的正确性。

There are complicated relationships among the radial suspension forces, configuration of windings and currents for a bearingless permanent magnet-type synchronous motors（BPMSM）, so researching these relationships has important reference value for designing and optimizing BPMSM. Based on the principle of producing radial suspension forces on BPMSM, the mathematics models of radial forces on BPMSM is deduced. The gap magnetic circuits of BPMSM are studied using finite element method when the currents in radial force windings are changed under the invariable equivalent current in torque windings. The relationship between the radial suspension forces and permanent magnet thickness is calculated and analyzed when the permanent magnet thickness is changed under the fixed motor gap. The radial suspension forces and the Maxwell forces of the additional 2-pole radial windings and additional 6-pole radial windings are compared under the 4-pole motor windings. The relationship between radial suspension forces and current is tested on prototype machine with pM=2 and pB=3 under the state of static suspension; the experiment conclusions have proved that the account results are accurate by using ANSYS software.