Design and Analysis of a New Linear Wound-Field Flux Reversal Machine Based on Magnetic Gear Effect

In this paper, a new linear wound-field flux reversal (LWFFR) machine for low-cost linear direct-drive applications is proposed. Similar to the conventional LWFFR machine, the proposed machine possesses the merit of a simple and compact long stator structure, a low cost, and a high flux adjustment ability. The novelty of the proposed machine is to be designed based on the magnetic gear effect. Hence, its force capability can be significantly improved without increasing the structural complexity and manufacturing cost. Meanwhile, the feasible combinations of mover pole and stator pole numbers for the LWFFR machines are extended, and thus provide a more flexible design choice. The operation principle and electromagnetic characteristic of a new optimal LWFFR machine are analyzed by means of the time-stepping finite-element method, verifying the effectiveness of the theoretical analysis.