A simple unipolar excitation strategy for switched reluctance motors by using PWM current control

Abstract

This paper presents a simple unipolar excitation strategy by using PWM current control for switched reluctance (SR) motors. In this technique, SR motors are non-sequentially excited by half sine-wave (HSW) currents which generate no negative torque. The implementation of this technique is simple and straightforward because SR motors are driven by adjusting only the peak value of the HSW current. Additionally, the PWM control strategy achieves the smooth current tracking and fixed switching frequency, and consequently improves the drive performances including the motor efficiency, vibration levels, and noise emissions. The effectiveness of the proposed technique is experimentally verified by comparing to the conventional unipolar current excitation on a 1kW three-phase SR motor.