Design and Analysis of a Novel Segmented PM Variable Leakage Flux Machine Considering Variable Flux Range

This paper proposes a novel variable leakage flux machine (VLFM) with segmented permanent magnets (SPMs), which is geometrically characterized by distinct flux-leakage bypass and has SPMs mounted on the rotor. The magnetic saturation status of the flux-leakage bypass and hence the leakage flux can be flexibly changed by controlling the load current. Thus, the air-gap flux regulation can be realized. The proposed SPM-VLFM has the advantages of low iron loss and high efficiency over a wide speed range, in which the required flux-weakening current and the associate excitation loss can be reduced. The machine topology and operating principle are introduced, respectively, and the multi-objective optimization is carried out to obtain the optimal design. Then, in order to validate the feasibility of the proposed design, the preliminary electromagnetic characteristics of the SPM-VLFM are compared with those of conventional machines with particular reference to the variable leakage flux property.