Comparison of Variable Flux Memory Machine and Double-Variable Flux Memory Machine with Hybrid Magnetic Circuits

This article introduces a dual-variable flux memory machine (D-VFMM) and contrasts it with a traditional VFMM. The D-VFMM introduces variable leakage flux to constitute the dual-variable flux together with the variable PM flux. By cleverly utilizing variable leakage flux, the D-VFMM can achieve the same high torque density as a conventional VFMM, while offering a broader flux regulation range simultaneously. The topologies of both the proposed and the benchmark machines are presented and described in detail. Then, the ability of the proposed machine to extend the flux regulation range is demonstrated through the equivalent magnetic circuit comparison with the benchmark machine. Finally, the electromagnetic characteristics of the two investigated machines are comprehensively analyzed and compared. The comparison results indicate that the proposed machine is capable of achieving basically equal output torque, wider flux regulation range and broader high efficiency region over the operation range.