Electric machine with continuous pole phase modulation

摘要

A pole phase modulated rotary electric machine is provided with a uniformly slotted stator structure and a main stator winding which spans the entire stator periphery. A control stator winding is wound in selected slots of the stator structure and the average phase change between adjacent slots of the stator structure is controlled by controlling the phase angle of current supplied to the control winding using a rotary magnetic induction phase shifter, an isolated variable reactance load, or a switching arrangement which varies the current amplitude and magnetic field axis of the controlled winding. Pole phase modulation provides a continuously variable magnetic speed control of induction type electrical machines operating at a fixed power frequency.