A Dual-Layer-Stator Doubly Salient Permanent Magnet Machine

A new doubly salient permanent magnet (DSPM) machine is proposed in this paper. Different from the existing counterparts, the proposed machine employs a two-layer stator, in which the inner stator layer is used to wound armature windings and the outer stator layer is used to employ PM excitation. In this case, the armature flux will not pass through the PMs, so the reluctance of the armature magnetic path is reduced, and the armature current possesses no demagnetizing risk on the magnets. Meanwhile, the proposed machine can achieve stronger PM excitation since there is more space for PM employment. The stator can be designed with several modules and manufacturing cost can be reduced during mass production. Design optimization is conducted on a 12/8 prototype, and the electromagnetic performance is investigated. The simulation results show that this proposed machine can be designed with a high torque density, and the PMs are protected from being demagnetized.