Comparison of Long Stator Three-Phase Winding Structures in a 2G HTS LSM for Maglev Application

Superconducting magnetically levitated (SC maglev) trains have developed rapidly in recent decades due to their promising features, such as a high cruising speed. A series of R& work has been done to develop second-generation high-temperature superconducting (2G HTS) maglevs, including regarding the design, optimization, and manufacturing of the on-board 2G HTS magnet system and ground propulsion system. This article is a continuation of this research progress, mainly focusing on the ground propulsion system of long stator three-phase windings. Different from a traditional linear synchronous motor (LSM), which uses a permanent magnet or electromagnet as the mover, a 2G HTS LSM uses superconducting magnets that generate a strong magnetic field in the air gap. Considering the balance of propulsive and normal forces, in addition to force ripples, a special structure with long stator three-phase winding must be designed; the thermal load from the non-synchronous magnetic wave on the HTS magnet is also an important design issue. Consequently, double-layer short-pitch winding has been designed for the HTS LSM.