Analysis and Design Optimization of Axial–Radial Flux Hybrid Excitation Permanent Magnet Eddy Current Coupling

This paper proposes an axial–radial flux hybrid excitation permanent magnet eddy current coupling (HE-PMEC), where the ferrite magnet is employed for producing the radial flux and the DC excitation current is adopted for producing the axial flux. Moreover, a shielding layer is developed to regulate the radial magnetic field. Its magnetic field distribution, electromagnetic performance, and temperature distribution are calculated based on the 3D finite element method (FEM). By adjusting the applied DC excitation current density and the insertion depth of the shielding layer, the variable current starting process, the variable current braking process, and the speed regulation characteristic of the proposed HE-PMEC are obtained. It can be seen that the starting process, braking process, and speed regulation ability of the HE-PMEC have been enhanced greatly. Furthermore, the copper ring shape of the HE-PMEC is optimized by using the proposed improved multilevel optimization method. It can be seen that the performance of the HE-PMEC can be improved by using the new optimized copper ring shape. Lastly, compared with the conventional PMECs, the proposed HE-PMEC has shown its superior electromagnetic performance.