Investigation of Partitioned Stator Hybrid Excited Switched Flux Machines With Different Rotor Piece Numbers

Hybrid excited (HE) machines employ both permanent magnet (PM) and field coil (FC) as the excitation sources, with potential synergies of high efficiency, high power density of PM machines and excellent flux controllability of electric-excited machines. In this paper, the partitioned-stator hybrid excited switched flux (PS-HESF) machines were investigated, which feature the stator-located FCs and thus the elimination of sliding contacts, as well as the dual stator structure to alleviate the space conflict. The PS-HESF machines follow the flux-switching principle, based on which the fluxes of the stationary excitation sources could be modulated by the salient rotor to generate the bipolar flux-linkage in the armature coils. After the introduction of the operating principle of the PS-HESF machines, the electromagnetic performances of the machines with different rotor piece numbers were evaluated and compared in details. It was revealed that the PS-HESF machines exhibit not only the high torque output but also the excellent flux regulation capability. Moreover, the influences of the key design parameters on the torque and flux regulation capabilities were illustrated, which could provide a guideline to the HE machine design. Finally, a pair of PS-HESF machine prototypes were fabricated and tested for the experimental validation. © 2021 Chin. Soc. for Elec. Eng.