Topology Exploration and Analysis of a Novel Winding Factor Modulation-Based Hybrid- Excited Biased Flux Machine

This article presents a novel permanent magnet (PM)-assisted flux-controllable machine, namely, the hybrid-excited biased flux machine (HEBFM). The proposed machine can implement flexible flux regulations (i.e., either field weakening or strengthening) by integrating the field current winding with the half consequence PM poles in the stator. The topology of the HEBFM can be explored in multipole cases, which contributes to improved flexibility for flux control and winding regulation. Compared with the conventional flux-controllable machines, the proposed machine gains the merits of owning: 1) extended flux control range via the modulation of winding factor (i.e., winding factor modulation); 2) stable and compact structure; 3) reduced demagnetization risk of PMs; and 4) capability of topology exploration. In this article, the operation principle and electromagnetic performance of the proposed machine are analyzed using the finite-element method (FEM). Besides, the torque and torque ripple are optimized based on multiobjective differential evolution (DE) coupled with FEM. Finally, a prototype is manufactured and tested to validate the effectiveness and feasibility of the proposed machine designs.