Comparative Analysis of Double Flux Modulation Flux Reversal Machines with PMs on Both Stator and Rotor

In this paper, two double flux modulation (DFM)flux reversal machines (FRMs) with PMs on both stator and rotor are introduced. The DFM-FRMs can be approximately viewed as the superposition of two flux modulation machines i.e. a consequent-pole FRM with rotor teeth modulation, and a consequent-pole vernier machine with stator teeth modulation. Therefore, the two DFM-FRMs share the similar operation principle. However, due to the different stator-PM arrangement, the two DFM-FRMs show different performances. In order to analyze their performance differences, four slot-pole combinations are selected and compared in terms of flux field, torque density, power factor, and overload capability. Finally, two slot-pole combinations with relatively better performances are selected and built. The test results match well with the finite element analysis (FEA) simulations and analytical calculations.