A Novel Separated Hybrid-Magnetic-Circuit Variable Flux Memory Machine

Abstract

Aiming at the problems of the existing hybrid-magnetic-circuit variable flux memory machine (HMC-VFMM), such as weak flux regulation (FR) capability and low efficiency in high-speed region, etc., this article proposes a novel separated HMC-VFMM (SHMC-VFMM), which innovatively arranges a series magnetic circuit on the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> -axis and a parallel magnetic circuit on the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i> -axis. The SHMC design can simultaneously reduce the PMs fluxes through low-coercive-force PMs configured on the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i> -axis and the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i> -axis, which will improve the FR capability. The magnetic saturation is alleviated by reducing the usage of high-coercive-force PMs, which further broadens the FR range. The proposed design also simplifies the rotor mechanical structure, thereby improving the rotor design flexibility. Firstly, the topological evolution process and the working principle of the proposed machine are interpreted in in succession. Then, the mechanism of further expanding the FR range of the proposed machine is revealed by comparing its equivalent magnetic circuit model with that of the existing machine. Subsequently, the electromagnetic characteristics of the two compared machines are analyzed by using the finite element method, which validates the performance advantages of the proposed machine. Finally, an SHMC-VFMM prototype is manufactured and measured to verify the superiority of the proposed SHMC design.