Reduction of Eddy-Current Losses in Fractional-Slot Concentrated-Winding Synchronous PM Motors

Abstract

This paper focuses on the reduction of eddy-current losses in fractional-slot inset permanent magnet motors. The flux paths of the armature reaction is modified based on pulsewidth modulation technique. Undesirable harmonic contents of the air-gap flux density can be reduced. This improves back electromotive force waveform quality and reduces the amplitude of eddy currents in the solid rotor and magnets. Rotor losses are strongly reduced by this technique.