Comparative Analysis of Doubly Fed Flux-Reversal Permanent Magnet Machines With Different PM Arrangements and Consequent-Pole Topologies

In this article, two doubly fed (DF) flux-reversal permanent magnet (FRPM) machines with different PM arrangements are proposed, both of which have an additional set of armature winding in their rotor slots to further enhance the torque performance. Together with their one-set armature winding counterparts, comprehensive analyses and comparison among these four machines are conducted. The operation principles and winding configurations of these four machines are firstly introduced. Then, based on finite-element (FE) method, the electromagnetic performances of four machines after optimization with the purpose of maximum torque are compared in terms of no-load, on-load, and over-load capabilities. The results show that the DF-FRPM machine with consequent-pole structure offers the highest average torque and lowest torque ripple, which make it a promising candidate for low-speed and high-torque applications. A prototype machine has been manufactured and the FE results have been verified.