Design and optimization of a slot-PM-assisted doubly-salient machine based on saturation assuaging

In this study, a novel slot PM-assisted doubly-salient machine (SPMA-DSM) is proposed based on saturation assuaging. In this machine, DC current is adopted as the excitation source. The permanent magnets assembled in slots are used to realize saturation assuaging, which can offer higher torque density and improved overload capability. Additionally, the torque density can be extended to wider scale before saturation. Multi-objective optimization based on differential evolution (DE) coupled with finite element method (FEM) is conducted to further improve the performance of the proposed machine. When compared to traditional flux-controllable machine, the PMAHEM exhibits the merits of: (1) higher torque density per PM volume, (2) lower torque ripple, and (3) wider flux controllable range. The simulation results indicate that the electromagnetic torque increases by more than 20% after the saturation assuaging design and optimization.