DSSRM Design With Multiple Pole Arcs Optimization for High Torque and Low Torque Ripple Applications

Double-stator switched reluctance motors (DSSRMs) are gaining much attention due to advantages of higher power/torque density and lower acoustic noise compared to conventional SRMs. In this paper, a novel three-phase 12/8/12-pole DSSRM design method is proposed by multiple pole arcs optimization for higher torque and lower torque ripple applications. A constrained quadrilateral is first presented to restrict the combinations of pole arcs according to motor operation conditions. Then, multiple parametric analysis processes are employed to analyze the effects of pole arcs on static torque in 3-D finite-element modeling environment. In order to select the optimal combinations of pole arcs generating higher torque, an effective torque evaluation principle is presented. Instead of the conventional 22.5° rotor position range, 15° range is adopted to calculate the average torque according to the static torque profiles, which is more effective to evaluate the torque capability. The selected torque range considers not only the excitation and demagnetization processes of phase currents but also the optimal range for torque generation. Finally, in order to achieve a lower torque ripple, the transient simulation is further carried out to identify the optimal pole arcs by comparing the torque ripple, average torque, and efficiency.