Analysis of Slot/Pole Combinations of a Novel Dual-Stator Axial-field Flux-modulated Machine with Split-teeth Stators

This paper investigates the optimal slot/pole combination of a novel dual-stator axial-field flux-modulated machine for in-wheel applications. The topology adopts the spilt-teeth stator and the consequent-pole (CP) PM rotor, in which the former structure allows the achievement of both high winding factor and high gear ratio, and the latter improves the PM utilization. However, the CP PM will induce the dc bias and harmonics with even numbers in the flux linkage, which should be taken into consideration in the slot/pole combination selection. Moreover, the optimal number of modulation teeth connected to each main tooth is investigated. Then, the electromagnetic performance including average torque and torque ripple are compared by the finite element analysis (FEA). Finally, a 12-slot/24-FMP/19-rotor-pole prototype is manufactured and tested to validate the above analysis.