A new flux-barrier-type reluctance motor with a slit rotor

A reluctance motor, with a rotor which has many slits, is proposed. The slits are used to generate magnetic flux in the d-axis direction. In practice, the rotor, which has a fewer number of slits, is desired to increase productivity. With a fewer number of slits, torque ripple becomes large. Therefore, torque ripple reduction methods are also proposed. In simulations and experiments, rated torque of the proposed motor is 1.7× as much as that of the conventional brushless DC motor with ferrite permanent magnets. The peak-to-peak (p-p) torque ripple is 1.5% p-p of the rated torque at the rated torque. The efficiency is 91% and the power factor is 61%, at the rated torque and 1200 min^-1. The characteristics of the field weakening and the constant power control are also shown. The breakpoint frequency of speed controls is about 200 Hz. Therefore, the proposed reluctance motor is feasible for general applications