Investigation of High Temperature Superconducting Linear Flux-Switching Motors With Different Secondary Structures

Compared with Linear Induction Motor (LIM), which is widely adopted for urban railway transit system, Linear Flux-Switching Permanent Magnet (LFSPM) motor has the merits of high efficiency, power factor and simple secondary structure. Therefore, LFSPM motor is claimed to be promising for urban railway transit system. However, research shows that speed range of LFSPM motor is limited due to Permanent Magnets (PMs). But for Linear Wound Field Flux-Switching (LWFFS) motor, electromagnetic performance is influenced by the large airgap. To incorporate the merits of LWFFS motor and LFSPM motor, High Temperature Superconducting Linear Flux-Switching Motor (HTS-LFSM) is proposed. However, it remains unknown which secondary structure of HTS-LFSM is suitable for urban railway transit. Hence, two HTS-LFSMs of slotted and segmented secondaries are designed, optimized, compared and analyzed in this paper. Finite Element Method (FEM) is adopted to calculate their performance.