DC-Bias Operation of a Double-Stator Hybrid Flux Switching PM Machine

The paper proposes the DC-bias operation of a new double-stator hybrid flux switching permanent magnet (DSH-FSPM) machine. Firstly, by directly injecting the DC current into the armature windings, the DC-bias strategy contributes both the flux enhancing (FE) and flux weakening (FW) capabilities to the machine design. Under the FE operating mode, compared with the pure-armature-slot-winding and pure-DC-slot-winding conditions, the DC-bias operation increases the average steady torque by 41.3% and 65.5%, respectively. Under the FW operating mode, the rotational speed can be greatly expanded from the rated 500 r/min to 1865 r/min. Besides, with the integration of the double-stator structure and FSPM topology, the proposed machine combines the benefits of high power density, high efficiency, and flexible controllability.