Radial Force Control of a Switched Reluctance Motor with Two-Phase Sinusoidal Excitations

Due to its special structure, the shaft radial force and torque of switched reluctance motor can be separately controlled by proper selection of pole currents. When all the pole currents are controlled independently, it is possible to produce the required radial force to cancel the existing radial force caused by non-uniform air gap or external load, and consequently motor vibrations can be reduced. In this paper, a radial force control scheme which use single or two phase sinusoidal excitations for 12/8 pole SRM is proposed. The pole currents of the conduction phase are energized with phase-shifted sinusoidal currents. Depending on the requested radial force and motor torque, the phase with descending-inductance may also be energized to increase radial force production. The requested force and torque are synthesized from the force and torque produced by these phases. The proposed scheme was verified with finite-element analysis and experiments