Numerical Study of Quasi-Static and Dynamic Levitation Forces for HTS Tape Stacks Under Simplified Methods Using H and T-A Formulation

Benefited from the good structural characteristics and thermal dissipation ability, high temperature superconductor (HTS) stacks are becoming more and more popular in superconducting applications, and can achieve a better performance with relatively few superconducting materials compered with the HTS bulk. However, due to the high aspect ratio of HTS tapes, it brings great challenges to the calculation on levitation force of HTS stacks. Simplified methods are proposed in this article, which combined with H and T-A formulations, to improve the efficiency of HTS tapes' calculation on the premise of ensuring accuracy. Then, H homogeneous model and T-A multiscale model are used to simulate the quasi-static levitation force, lateral force, dynamic levitation force, and dynamic stability, combined with motion equations. We compare and analyze the calculation time and accuracy of the results of electromagnetic force calculated by the two simplified models significantly. It is found that the current density distribution of the simplified models has a good agreement. The electromagnetic force error between the two simplified models gradually accumulates with the increase of layers. Whether the quasi-static system or dynamic system, the electromagnetic force is calculated using the T-A formulation in a much shorter time than the H formulation and the accuracy is guaranteed.