Dynamic Electromagnetic Behaviors of High-Temperature Superconductor Levitation System Based on YBCO Material from 3D Perspective

In this paper, a 3D numerical model, which was theoretically established and experimentally validated, was utilized to investigate the dynamic electromagnetic behaviors of a high-temperature superconductor (HTS) levitation system consisting of a cylindrical permanent magnet (PM) and an HTS fabricated by the YBCO material. The effects of critical current, cooling temperature, multiseeded material, and thickness of the HTS on electromagnetic behaviors were discussed from a 3D perspective. The dynamic electromagnetic behaviors indicate the induced current is mainly distributed near the top surface and edges of the HTS. As the PM approaches the HTS, the induced current density increases gradually. As the PM withdraws, it reduces initially and is then induced in the opposite direction. The levitation force increases with critical current but exhibits saturation. The lower the temperature, the larger the levitation force and the smaller the hysteresis. The induced current of the multiseeded HTS is characterized by a symmetrical distribution with the seed domain boundary or central axis. Its maximum value increases with the number of seeds but the levitation force significantly reduces. The induced current on the cross section is symmetrically distributed. As the thickness of the HTS decreases, the levitation force reduces drastically but the maximum value of the induced current increases. The reason was explained. Finally, the dynamic electromagnetic behaviors of a radial-type HTS bearing were investigated from a 3D perspective.