Performance Improvement for Superconducting Linear Synchronous Motor With General Racetrack Coils

A novel structure for the air-cored superconducting linear synchronous motor (SLSM) with general racetrack coils is proposed in this work. The elliptical edge with variable shape is designed to decouple the geometric parameters of the coil and to optimize the electromagnetic thrust of SLSM for minimizing the force ripple while ensuring sufficient thrust output. A 3D analytical model is established to investigate the electromagnetic characteristics of the proposed SLSM. The Biot-Savart Law and the virtual displacement method is introduced in this model to predict the no-load magnetic field, thrust and back electromotive force (EMF) of the SLSM. The accuracy of the proposed model was verified through finite element method (FEM) and experiment. The SLSM of the Yamanashi test line is introduced in this work as a case study. The on-board superconducting and armature coils were optimized based on the novel structure. Comparison between the SLSMs with the proposed and initial coils were carried out and the results demonstrate the superiority of the novel structure in terms of thrust output. Additionally, the proposed SLSM is promised to reduce the material consumption and thus the cost of the electrodynamic suspension system.