High-temperature superconducting (HTS) magnet, due to its greater performance of magnetic field at higher temperature (20–40 K), better thermal stability, smaller volume and weight under the same requirements, and lower refrigeration costs, has attracted growing attention in the ultra-high-speed maglev system, high field magnet, and some other applications. Considering the practical requirements, closed-loop method is generally adopted in HTS magnet to maintain the persistent operation and to output the stable magnetic fields. But the accelerated current attenuation occurs when the HTS magnet is subjected to traveling magnetic fields, which is not conducive to the long-term operation. Therefore, this paper aims to investigate the essence of current attenuation of HTS magnet in persistent current mode under traveling magnetic fields and to further suppress this adverse behavior. In this study, to calculate the current distribution and dynamic resistance, a two-dimensional (2-D) finite element model (FEM) was established and verified by comparing with the experimental results. It can be seen from the simulation results that the dissipative losses caused by dynamic resistance present a non-negligible effect on the current attenuation of the magnet. And the mechanism of faster current attenuation was well explained by the variation of the dynamic resistance under the traveling magnetic fields.

高温超导（HTS）磁体由于在较高温度（20– 40 K）下具有更强的磁场性能，更好的热稳定性，在相同要求下更小的体积和重量以及更低的制冷成本，已引起越来越多的关注。超高速磁悬浮系统，高磁场磁体以及其他一些应用。考虑到实际需求，高温超导磁体一般采用闭环法来保持持续运行并输出稳定的磁场。但是，当HTS磁体受到行进磁场的作用时，会加速电流衰减，这不利于长期运行。因此，本文旨在研究在行进磁场下恒流模式下高温超导磁体电流衰减的本质，并进一步抑制这种不利行为。在本研究中，为了计算电流分布和动态电阻，建立了二维（2-D）有限元模型（FEM），并与实验结果进行了比较。从仿真结果可以看出，由动态电阻引起的耗散损耗对磁体电流衰减的影响不可忽略。通过行进磁场下动态电阻的变化很好地解释了更快的电流衰减机理。建立了二维有限元模型（FEM），并与实验结果进行了比较验证。从仿真结果可以看出，由动态电阻引起的耗散损耗对磁体电流衰减的影响不可忽略。通过行进磁场下动态电阻的变化很好地解释了更快的电流衰减机理。建立了二维有限元模型（FEM），并与实验结果进行了比较验证。从仿真结果可以看出，由动态电阻引起的耗散损耗对磁体电流衰减的影响不可忽略。通过行进磁场下动态电阻的变化很好地解释了更快的电流衰减机理。