Design and Evaluation of Modular Stator Hybrid-Excitation Switched Reluctance Motor for Torque Performance Improvement

To address the challenge of low torque density of conventional switched reluctance motor (SRM), this article introduces a modular stator hybrid-excitation SRM (MS-HESRM) with a π-type structure. Permanent magnets (PMs) are magnetized in circumferential direction and placed in stator yoke between the adjacent π-type modules, which enhances the flux flowing through the torque poles and thus improves the output torque. First, the operation principle of proposed structure is explained. And the magnetic circuit model is analyzed to reveal the torque contribution of PMs. Furthermore, the influence of structural parameters on the output performances such as average torque, torque/PM volume, and cogging torque, are investigated using finite-element method. To demonstrate the merits of proposed structure, a prototype is manufactured, and comparisons with other hybrid-excitation SRMs are implemented including average torque, torque/PM volume etc. Simulation and experimental results illustrate that the proposed MS-HESRM has high output torque, PM utilization and torque density.