Design and Analysis of Permanent Magnet Assisted Switched Reluctance Motor Considering Iron Core Saturation

Modular design and permanent magnet (PM) assisted (PMA) design are effective methods to improve the torque performance of switched reluctance motors (SRMs). In this paper, the operating principle of a PMA-SRM with U-shaped stator modules and PMs inserted in the slot-openings of stator module is investigated considering the iron core saturation based on the magnetic circuit analysis of PM and armature fields. Then two key dimension parameters of stator tooth width and PM height are designed according to the action mechanism of PMs. In order to verify the theoretical design, the multi-objective genetic algorithm is employed to optimize the PMA-SRM. The electromagnetic performances of the optimal motor are calculated and analyzed. Especially, the cogging torque and the reluctance torque produced by the PMs are calculated separately based on the frozen permeability method. Thus, the function of PMs for the torque improvement can be verified clearly. Finally, the prototype is manufactured and tested. The tested result agrees well with the simulated one.