Multi-phase electric motor with third harmonic current injection

摘要

Significantly increased torque is provided from a motor having a stator with a core and at least two three-phase windings wound on the core. The two windings are separated spatially by 30 electrical degrees. Power is provided to the two windings by two power supplies which each provide power at the same fundamental frequency and with a component at the third harmonic of the fundamental, with the power provided from one power supply shifted in time by 30° of the fundamental frequency with respect to the power provided by the other power supply. The additional third harmonic component reduces the effective peak flux density, allowing an increase in the fundamental component of flux to allow an increase in effective torque, with the third harmonic component also providing additional torque.