永磁直流电机定子的振动分析

Analyses of permanent magnet DC motor stator vibrations

永磁直流电机的定子振动具有鲜明的特性,对它的分析对于分析其他各类电机的振动具有借鉴作用。该文用解析法分析了电机内的磁场和径向电磁激振力,从物理概念上定性解释了直流电机振动的特征。特别地,指出永磁直流电机槽频电磁激振力的阶数与定子振动形态的空间阶数不同。为准确计算电机振动,利用电磁场有限元仿真了电机内的磁场与电磁力分布,并采用结构场有限元对定子振动进行了仿真。针对试验测试,指出为得到定子振动形态特征,需要在定子上测量足够多的测点。并在一台实际的直流电机上进行振动测试,试验结果与仿真结果相符。

Stator vibrations in permanent magnet DC motors have distinct characteristics which are also useful for analyzing other types of motors. The magnetic fields and the electromagnetic forces in permanent magnet DC motors were analyzed to characterize the physical mechanisms driving the vibrations. The order of the slot-frequency electromagnetic exciting force is not equal to the spatial order of the stator slot-frequency vibration shape. Accurate analyses of the vibrations inputs the magnetic field and electromagnetic force distributions calculated by finite element simulations into a structural finite element simulation to predict the stator vibrations. Experiments must have enough sensors to obtain the vibration mode shape. The predictions agree weU with data from DC motor tests.