A Novel Axial-Field Juxtaposed Magnetic Circuit Variable Flux Memory Machine

To achieve the goal of coexisting wide regulative speed range and high efficiency in high-speed operation, a novel axial-field juxtaposed magnetic circuit variable flux memory machine (AF-JMCVFMM) is proposed, which combines the high power density of axial-field permanent magnet machine (AFPMM) and wide speed regulation range of variable flux memory machine (VFMM). Firstly, the topology and variable flux principle are introduced. Subsequently, the main parameters are designed and optimized based on the equivalent magnetic circuit (EMC) and finite element method (FEM). Then, the electromagnetic performance of the proposed machines is compared and analyzed. The results indicate that the wide regulative speed range and the expansion of high efficiency region can be achieved by the proposed machines, which have profound prospects in the field of variable speed traction applications.

I. Introduction

The development of electric drives in traction equipment has been widely recognized as the main solution to address the challenge of carbon neutrality. High power density and compact structure are possessed by axial-field permanent magnet machine (AFPMM) making it a prominent choice for electric vehicles variable speed applications [1].