单相绕组变极异步电动机定子磁场特性分析

Stator magneticfield characteristics of asynchronous motors with variable-pole single winding

倍极比为2／4的单相绕组变极调速三相异步电动机的定子磁场，因绕组的接线方式不同而与普通单极对三相异步电动机的差异甚大。在4极运行模式时，单相统组在气隙圆周方向产生的磁动势波形比后者密1倍，其三相绕组合成磁场的同步旋转速度Ω2＝ω／2。在2极运行模式时，单相绕组在气隙圆周方向的磁动势分布与后者完全不同，其三相绕组合成磁场的同步旋转速度Ω1＝－ω，方向与4极运行时相反。

The stator magnetic-field of three-phase asynchronous motor with variable-pole single winding and a pole-to-pole of 2/4 is quite different from that of ordinary three-phase asynchronous motor with single number of pole-pairs owing to the difference of the connection mode of winding. In four-pole working mode, the single-winding magnetic motive force (mmf) waveform of the former is double that of the latter in density in the direction of air-gap circumference, and the synchronous rotating speed of the resultant magnetic field of the former is half of that of the latter. In two-pole working mode, the mmf distribution of the former is quite different from that of the latter in the direction of air-gap cireumference,and the synchronous rotating speed of the resultant magnetic field of the former is equal and opposite to that of the latter.