Performances of Current-Waveform Modulated Single-Phase Induction Machine

전류파형을 변조한 단상유도전동기구의 특성에 관한 연구

A single-phase induction motor with it's stator winding splitted into two series windings, of which the terminals of one winding is switched pulsationally by a thyristor type ON-OFF device so that the motor may operate as a pulsational shaded-pole motor, can modulate current waveforms of it's two series windings. In view of current waveform modulation method, a single-phase single-winding motor operates as a two-phase induction motor with asymmetrical axis windings where the starting torque can be obtained effectively without an auxiliary capacitor attached and it's running speed controlled by shifting phase between current waveforms differently. Equivalent circuit for analysis is modified from a double revolving field equivalent circuit of a single-phase induction motor with asymmetrical windings whose angle is 45.deg.C elet. degrees. Analysis and test results show that ON-OFF action of the pulsational shaded-pole winding has the same effect of a series capacitor, and then at heavy loads this motor operates with a small amonut of the input current than that having the fixed shaded-pole winding.