A Novel Hybrid-Pole Variable Flux Memory Machine With Integrated Series-Parallel PM Topology

In order to address the challenging issues of complex multilayer rotor structure, unsatisfactory flux regulation (FR) capability, and relatively limited global efficiency enhancement of the existing hybrid-magnetic-circuit variable flux memory machine (HMC-VFMM), this article proposes a novel hybrid-pole variable flux memory machine (HP-VFMM) with integrated series-parallel magnetic circuit. The machine is composed of specially designed hybrid magnetic poles with a sequent flat-type and V-type permanent magnet (PM) configuration. Besides, the hybrid magnetic circuit can be formed within a simple single PM segment, contributing to a relatively independent relationship between series and parallel branches. The design of bypass iron bridges is employed to extend the FR range, as well as decrease the required FR current effectively. First, the HP-VFMM topology and operating principle to realize an extended FR range are introduced. Then, the equivalent magnetic circuits of the proposed HP-VFMM and an HMC-VFMM counterpart are established to analytically identify the underlying performance enhancement mechanism. Afterward, the electromagnetic performance comparison of the two machines is conducted based on the finite element (FE) method to confirm the foregoing theoretical analyses. Finally, an HP-VFMM prototype is manufactured to validate the feasibility of the proposed design.