内燃机用自由活塞永磁直流直线发电机分析

Analysis of Free-Piston Permanent Magnet DC Linear Generator Used for Internal Combustion Engines

提出了一种新结构的自由活塞永磁直流直线发电机。电机为圆筒形,粘贴在动子支架上的永磁体由内向外沿径向充磁,通过内静子铁心与动子支架间的穿插配合,从静子上看动子只有一个磁极,静子上只有一组串联绕组,当永磁体动子朝一个方向运动时,电动势方向不变,可看作直流永磁直线发电机。通过三维有限元分析计算,指出设置磁路调整环的必要性;给出了有效削弱齿槽力波动的方法;得到了反映电机性能的电感、电动势和电磁推力等重要参数或曲线。

A novel free-piston permanent magnet DC linear generator structure was proposed. The generator was cylin- drical. And the permanent magnets were magnetized radically and adhered on the mover＇s bracket. The internal stators were fixed at the external stators＇ brackets through the mover＇s bracket. Viewed from the stator, the mover had only one magnetic pole. The stator was winded with one set of windings in series. When the permanent magnet moved in one direction,the di- rection of EMF was unchanged. The proposed generator operated in the same manner as a DC permanent magnet linear gen- erator. By 3-D finite element analysis, the necessity of setting the adjusting ring of magnetic circuit and the effective way to reduce cogging force fluctuation were verified. The parameters such as the inductance, EMF, and electromagnetic thrust were calculated,which indicated the generator performance.