Novel Multiple Magnetic Source Axial Flux Modulation Machines for Aviation Propulsion Applications

Aviation propulsion applications demand extremely high power and torque densities in electric machines. For the purpose of improving torque density, this article proposes and investigates a novel multiple magnetic source axial flux modulation machine (MMS-AFMM). The innovation lies in incorporating four sets of magnets within a single machine, achieving very high torque density. Initially, the machine topology, operation principle, and slot-pole combinations of the MMS-AFMM are explored. The feasibility of the proposed topology is demonstrated by theoretical and finite element (FE) analysis. Then, the torque and power factor are improved by using different rotor structures. The results show that the proposed MMS-AFMM attains a volumetric torque density of 100 kNm/m3 and a gravimetric torque density of 19 Nm/kg, offering significant potential for weight and volume-sensitive applications.