Investigation of a Partitioned-Primary Hybrid-Excited Flux-Switching Linear Machine With Dual-PM

A novel partitioned-primary hybrid-excited flux-switching linear machine with dual-PM excitation (DP-PPHEFSLM) is proposed and investigated in this paper. Unlike conventional single-primary hybrid-excited topologies, this proposed topology separates armature windings and field windings into two different parts of the partitioned-primary, with each part also having sandwiched or buried PMs. Due to greatly increased armature and field slot areas, it thus solves the problem of a crowded primary, which is typically encountered with conventional structures. Besides, the thrust density is further increased by skillfully positioning PMs on both primary parts. In this paper, first, the topology, operation principles, and viable primary/secondary pole-number combinations of the proposed machine are elaborately addressed. Based on 2D finite-element method (FEM), the proposed machines are globally optimized using genetic algorithms and their electromagnetic performances further investigated. Moreover, the proposed machine is compared with conventional topologies in terms of electromagnetic performances, which shows that the proposed machine exhibits multiple merits such as higher thrust density, improved space utilization, and more flexible flux control capability. Finally, a 6/7 DP-PPHEFSLM prototype machine is manufactured and tested to validate the 2D FEM-predicted results.