Design and Optimization of Novel Doubly-Fed Consequent-Pole Flux Reversal Machine

Conventional consequent-pole flux reversal machine (CPFRM) can effectively reduce the pole flux leakage and improve the torque density. However, the torque improvement is quite limited. This paper proposes a doubly-fed (DF) CPFRM (DF-CPFRM) with two independent sets of armature windings placed on stator and rotor slots, which can realize better rotor space utilization and significant torque enhancement. First, the machine configurations and operation principles are introduced. Then, the optimization aiming at maximum torque while maintaining high fault tolerance are elaborated. The influence of main geometric parameters including split ratio, stator and rotor slot opening ratio etc. on the torque performance is also explicated. Moreover, the optimized DF-CPFRM is compared with the conventional CPFRM in terms of back-EMF, electromagnetic torque and overload capability etc. using finite element (FE) method.