Design and Preliminary Prototype Test of a High Temperature Superconducting Suspension Electromagnet

This paper presents the development of maglev train and superconducting technology in China. Aiming at the heating problem of normal suspension electromagnet, a high temperature superconducting (HTS) suspension electromagnet based on Bi-2223/Ag tape was designed. We tested the heating condition of normal suspension electromagnet and designed the structure, size and technical parameters of the HTS suspension electromagnet. Considering the high sensitivity of Bi-2223/Ag tape to the magnetic field perpendicular to its surface, the finite-element method (FEM) software was used to analyze and calculate the vertical component of magnetic field. The FEM simulation results have proved the feasibility that the HTS suspension electromagnet could work normally in liquid nitrogen with the relationship between critical current and vertical magnetic field extracted from the measurements in factory. A prototype was produced and tested. The test results show that the HTS suspension electromagnet could work steadily under the conditions of 77 K, influence of vertical magnetic field and larger exciting current than 20 A, which indicates the design of HTS suspension electromagnet has reached the level of practical projects.