Proposal and Optimal Design of an Air-Cored Linear Synchronous Motor With Bézier-Track Armature to Suppress the Thrust Ripple

The linear motor-driven Maglev train has the advantages of high operation speed, high efficiency, safety, and comfort. Indicators such as thrust ripple and force density of the linear motor are crucial and affect the dynamics of the train. In this article, a novel structure of armature winding is proposed for the application of superconducting electrodynamic suspension (EDS) train, in which the central line of the armature coil is characterized by a Bézier-curve track. By adequately adjusting the coordinates of control points, the optimal structure parameters of the air-cored linear synchronous motor (LSM) could be obtained to suppress the thrust ripple and improve the force density. To validate, an analytical model of the air-cored linear motor with Bézier-track winding is established based on the principle of dynamic circuit method; then, the analytical predictions are verified by both finite element model and experimental results. Based on the proposed model, a multiobjective optimization process is proposed to determine the control points of Bézier-curve. Afterward, the electromagnetic force characteristics and thrust ripple suppression of the linear motor with Bézier-track armature are further investigated. The results show that the proposed linear motor can effectively suppress thrust fluctuation and gain a higher thrust density.