Comprehensive Comparison of Modular Transverse and Axial-Modular Flux-Switching Permanent Magnet Machine

This paper proposes a novel modular transverse flux-switching permanent magnet (MTFSPM) machine, which is evolved from the axial-modular FSPM (AM-FSPM) machine and the transverse flux (TF) machine. Both the MTFSPM and AM-FSPM machines belong to the category of modular magnetic field modulation machines. A comparative analysis between the MTFSPM machine and the AM-FSPM machine is then conducted. Based on the magnetic field modulation theory, the similarities and differences between the magnetic field harmonics of the MTFSPM machine and the AM-FSPM machine are analyzed. From the perspective of harmonic contributions to torque, the reason for the high output torque capability of the MTFSPM machine is revealed. Furthermore, based on the torque-sizing equation, the output torque of the MTFSPM machine is compared with that of the AM-FSPM machine from the perspectives of magnetic load and electrical load, establishing the mapping relationship between output torques and machine parameters. It is found that the MTFSPM machine has higher output torque due to its transverse magnetic circuit and higher pole arc coefficient. Subsequently, a comparison of the electromagnetic performances of the MTFSPM and AM-FSPM machines is conducted, showing that the MTFSPM machine exhibits lower torque ripple and better overload capability. Finally, experimental validation is conducted.