Minimizing Torque Ripple in 5-Phase Switched Reluctance Machines Using Half-Sinusoidal Current Pulses

Switched reluctance machines feature interesting characteristics such as manufacturing simplicity, no need for costly permanent magnets, excellent robustness, decoupled phases and high fault tolerance. Nevertheless, when designed according to the classic operation principle, i.e. featuring just 3 phases to be supplied with ideally rectangular current pulses possibly under deep saturation conditions, they exhibit large torque ripple, vibrations and noise. This paper proposes a different concept based on 5 phases to be supplied with half-sinusoidal current pulses under linear or mild-saturated conditions, ideally permitting to suppress torque ripple. The concept is investigated using a magnetically linear analytical model and is then validated by means of simulations including finite-element analysis, which confirm the theoretical expectations.