Design Consideration for E-Core Outer-Rotor Flux-Switching Permanent Magnet Machines From the Perspective of the Stator-Poles and Rotor-Teeth Combinations

To furnish an instructive guideline for the design of E-core outer-rotor flux-switching permanent magnet (OR-FSPM) machines, the stator-poles and rotor-teeth (P-T) combinations are investigated through the machine unit model in this paper. Based on the operating and complementary principles, the P-T combination selection principle for E-core OR-FSPM machines is established with the purpose of attaining a high-purity sinusoidal phase flux and a concurrently reduced cogging torque. With the P-T combination selection principle, a case study on the three-phase E-core OR-FSPM machine is presented to demonstrate the effectiveness and reliability of the proposed methodology. The design and optimization considerations are extracted as well during the process. Moreover, an optimization framework is established and four E-core OR-FSPM machines with various P-T combinations are optimized simultaneously within the prescribed procedure. The optimization results indicate that the optimization procedure will not compromise the validity of the selected P-T combination in the preliminary design stage. Consequently, the performances of the optimized E-core OR-FSPM are verified through the prototype experiment, which further confirms the efficacy of the proposed P-T combinations selection principle.