Optimal combination of pole configuration and current waveform of SRM for torque maximization

This paper presents a novel approach to achieve both the maximum torque-per-(amp/sup 2/) ratio and minimum torque ripple by selecting the optimal combination of current waveform and pole configuration. The idea is based on a principle that there exists a special combination of space harmonics of inductance and time harmonics of current which improves the torque/current ratio and, at the same time, eliminates the torque ripple. Following the general torque analysis, the pole configuration is designed to have a predominant third space harmonic of inductance and the current is regulated to have a predominant third time harmonic. The amplitudes of these harmonic components can be given by a simple relation. The validity of the proposed approach has been verified by simulations and experimental studies using a 1.5 kW switched reluctance motor.