Performance evaluation of a racetrack high temperature superconductor winding in an HTS levitation platform

Abstract High temperature superconducting (HTS) is a key technology for next generation high-speed railway systems, which guarantees high current and highly efficient traction power supplies. HTS devices can reduce system weight and thus improve loads of vehicles. In high-speed maglev trains, HTS windings wound by second-generation HTS tapes play an important role in suspension and traction. However, in complex ferromagnetic environments, the performance of windings is notably influenced by the varying magnetic fields. In this paper, a new maglev platform is designed and comprised of a winding of six racetrack HTS coils, an E-shaped iron core and a magnetic guide rail. The air core structure of the winding is modeled and tested and the electromagnetic characteristics are analyzed for three dimensional finite element analysis of the platform. An A formulation is used to calculate magnetic vectors A and infer magnetic flux densities and current densities for the structures. After the winding is installed on the iron core and the magnetic guide rail is suspended above the iron core, the air gap between the iron core and the rail is varied from 0 mm to 20 mm in models and experiments. The magnetic fields, critical currents and losses of the winding in the cases of the air core and the iron core conditions are used for analysis. The comparison between the air core and the iron core conditions confirms the reliability of the proposed models. This study provides a means for the analysis of complex superconducting maglev systems.