Performance Improvement in the Axial Flux-Segmented Rotor-Switched Reluctance Motor

Axial flux-segmented rotor-switched reluctance motor (SSRM) topology could be a potential candidate for in-wheel electric vehicle application. This topology has the advantage of the increased active surface area for the torque production as compared to the radial flux SSRM for a given volume. To improve the performance of axial flux SSRM (AFSSRM), various stator slot/rotor segment combinations and winding polarities are studied. It is observed that the torque ripple is high for the designed three-phase, 12/8 pole AFSSRM. Therefore, the influence of the stator pole and rotor segment arc angles on the average torque and the torque ripple is studied. In addition, the adjacent rotor segments are displaced with respect to the stator, to reduce the torque dips in the phase commutation region. The proposed arrangement is analyzed using the quasi-3-D finite-element method-based simulation study and it is found that the torque ripple can be reduced by 38%. Furthermore, the low-frequency harmonic content in the torque output is analyzed and compared. The variation of the axial electromagnetic attractive force with displaced rotor segments is discussed. The effectiveness of the proposed technique is verified experimentally.