A novel E-core hybrid-excited flux switching machine based on biased flux

This paper presents a biased flux hybrid-excited flux switching (BFHEFS) machine to improve the flux adjustability. The proposed configuration adopts E-core to enhance the permanent magnet (PM) material utilization ratio, which use half PMs of the conventional flux switching PM (FSPM) machine. The flux-adjusted principle of the E-core BFHEFS machine is introduced to explain the better flux adjustability than the existing hybrid-excited flux switching (HEFS) machine. Moreover, the influence of some key parameters on the output torque and flux adjustability are investigated. However, due to the asymmetric saturation of the magnetic path, the back-EMF of the proposed E-core BFHEFS machine occurs phase shift when the current of field winding changes, i.e., flux-regulating. A simple method, i.e., both the stator and rotor are segmented, is proposed to eliminate the phase shift. The results based on finite element (FE) analyses confirm that the flux adjustability is favorable.