Development of Novel Controllers for an Axial-Flux Switched-Reluctance Motor

Abstract

To increase the utility of switched-reluctance motors (SRMs) in electric vehicles it is required to increase torque per unit volume (torque density) while maintaining low cost and low torque ripple. This paper presents the design of three new control methods for in-wheel axial-flux SRMs that increase torque density using switching angles and optimal current profiles. All three control methods are compared to two reference control methods from the literature. The second method is shown to be superior in terms of the precision of its switching angle calculations to the first, and speed to the third, though the first method produces lower torque ripple, and the third uses a better model of switching dynamics. In addition, both first and second methods reveal improved performance compared to the control methods adopted from the literature. Thus, all three proposed control methods can be used to improve the performance of in-wheel SRMs, but the second method produces the highest torque density. The second method can be used for in-wheel motor applications which need online switching angle calculations that balance the requirements of high torque density and low torque ripple.