Rotor Reconstruction to Reduce Iron Losses in Partitioned Stator Flux-Modulation Machine

In this paper, a rotor reconstruction method based on the air-gap field coding is proposed to reduce iron losses of the partitioned stator flux-modulation (PSFM) machine. First, the armature and permanent magnet magnetomotive force (MMF) models are established, respectively. Considering the double air-gap modulation effect of the PSFM machine, the amplitude and rotation velocity of each harmonic are analyzed. Then, the contributions of each harmonic component in the air gap to iron losses are separated. Subsequently, an air-gap permeance model that determines the characteristics of harmonic components is established. On this basis, air-gap harmonics can be weakened by encoding the amplitude of the permeance. Simultaneously, the improved permeance harmonic components are reconstituted to guide the new rotor structure without optimizing parameters of the machine. The proposed rotor structure can effectively suppress the iron losses of the PSFM machine. Finally, a prototype of the rotor reconstructed PSFM machine is manufactured and tested to verify the effectiveness of the analytical results.