Design and Analysis of a New Unequal Consequent Pole Flux Reversal Machine for High-Torque-Density

Flux reversal machines (FRMs) have attracted numerous interests in academia due to high power density and simple structure. However, conventional FRMs cannot be applied in electric vehicles due to low torque densities. This paper proposes a new unequal consequent pole flux reversal machine (UCPFRM) for high torque density, in which the working harmonic amplitudes of airgap flux density are improved. The proposed UCPFRM employs two pairs of CPs on each stator tooth, which features that the widths of PMs are twice that of iron poles. The stator/rotor pole combination is designed based on optimal back-electromotive force and analytical modeling of the proposed UCPFRM is provided. Meanwhile, the calculation factor of magnetic electromotive force series term amplitude (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i>) within the model is proposed and the optimal PM structure is proposed by the reasonable <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i>. In addition, the configuration and design considerations of the proposed UCPFRM are described, followed by electromagnetic performances evaluated using finite element analysis. The merits of the proposed UCPFRM are that the torque density and torque quality are increased by 46.3% and 96.3% compared to the conventional FRM, respectively. The prototype of the proposed UCPFRM is manufactured, and intensive experimental tests are done to confirm the merits.