空心杯电机永磁体不同拓扑结构的比较分析

Comparative Analysis of Different Topologies of Permanent Magnets for Coreless Motor

介绍了空心杯电机永磁体常用的结构形式,并针对瓦片形磁钢和环形磁钢、径向充磁和平行充磁、有无磁轭等六种永磁体的拓扑结构,通过有限元仿真分析了不同拓扑结构的优缺点。结果表明,在相同的电机体积下,平行充磁环形磁钢具有最大的平均气隙磁密和接近正弦的气隙磁密波形,优于其他拓扑结构;在环形磁钢和导磁轭总体积一定的情况下,环形磁钢可不用导磁轭,因为环形磁钢增加导磁轭所带来的磁通增加不足以弥补磁钢体积减小带来的磁通损失。这两个结果为空心杯电机的永磁体选型提供了依据。计算了不同拓扑结构相应的计算极弧系数,为空心杯电机使用磁路法计算电机参数提供了参考。

The common structure of permanent magnet for coreless motor was introduced. Aiming at the magnetic flux of permanent magnets, the advantages and disadvantages of six topological structures, such as tile magnet and ring magnet, radial and parallel magnet, yoke or not, were analyzed by finite element simulation. The results show that for the same motor volume, the parallel magnetized ring magnet has the largest average air-gap magnetic density and nearly sinusoidal air-gap magnetic density waveform, which is better than other topologies. When the total volume of the ring magnet and the magnetic yoke is certain, the ring magnet does not need the magnetic yoke, because the increase of the ring magnet is not enough to compensate for the magnetic flux loss caused by the decrease of the magnet volume. These two results provide a basis for the selection of permanent magnets for coreless motors. The calculated polar arc coefficient was also calculated, which could provide reference for the design of coreless motor.