Force Modeling and Analysis of a Tube Flux-Switching Transverse-Flux Permanent Magnet Linear Motor

The permanent magnet linear motor (PMLM) has a variety of outstanding topological structures, such as flux switch structure and transverse flux structure. However, the inherited cogging force of PMLM is difficult to reduce without thrust damage. To solve the above-mentioned problem, this article investigates the thrust force, based on a novel flux-switching transverse-flux PMLM (FSTFPMLM) with a simple structure systematically, and provides the guidance to design the FSTFPMLM to achieve a larger thrust, with smaller cogging force. First, the basic structure and working principle of the FSTFPMLM are introduced. Second, an equivalent permeance model of the FSTFPMLM is proposed to calculate the thrust force, including cogging force, permanent magnet thrust, and winding reluctance force. Then, the leading parameters’ influence on the thrust force is investigated; it is concluded that the method effectively minimizes the cogging force and increases the thrust force. Finally, the prototype is manufactured, experiments are performed, and the experimental results agree well with the finite-element method results. This article verifies the effectiveness and practicability of the motor and the proposed analysis method, pointing out the motor's outstanding advantages in reducing cogging force while maintaining high thrust force.