Design and analysis of a novel dual stator axial flux spoke-type ferrite permanent magnet machine

This paper proposes a novel dual stator axial flux spoke-type permanent magnet (DSAFSPM) machine for the purpose of improving torque (power) density and reducing cogging torque and torque ripple. This machine adopts low cost ferrite permanent magnets inserted into the rotor as a spoke-type array. Two stators with the same slot/teeth construction are arranged to be shifted by one stator tooth width. Three phase-group concentrated-coil windings are placed into the slots. In order to highlight the contribution of the novel configuration to the proposed DSAFSPM machine, the electromagnetic characteristics such as air-gap flux density, permanent magnet (PM) flux linkage, back EMF, cogging torque, torque ripple, and torque density are compared with those of a basic DSAPSPM machine with two axially aligned stators based on 3-D finite element method (FEM).