In this work we present a computational model for a magnetic levitation system based on stacks of 12 mm x 12 mm second generation GdBa2Cu3O7-x high temperature superconducting (HTSC) tapes. In our model we have used the magnetic and transport characteristics of real industrial HTSC tapes. The thermal properties of each layer of high-temperature superconducting tape and the features of the layered structure of whole stack have also been taken into account. The numerical simulation was performed using the finite element method. Distributions of both magnetic field throughout the space and the current in every tape of the stack were calculated for two cases: (i) cryocooler cooling mode and (ii) cooling in the liquid nitrogen. The magnetization curves of the stacks in external field of a permanent NdFeB magnet and levitation force dependence on the gap between the magnet and the HTS tapes stack in these cooling modes were obtained. We have calculated heat transfer and temperature distribution in the system taking into account the effect of thermal properties of Hastelloy substrate, as well as Cu and Ag stabilization layers on the cooling process and dynamic magnetization. Simulation results were compared with the experimental data and a good agreement with numerical ones was shown.

This paper presents the results of complex multiphysical modelling of non-equilibrium states arising in high-temperature superconducting composites under current, magnetic, and combined control switching impacts types. The simulation and analysis of the dynamics of electrophysical and thermal processes occurring in the HTS composites layered structure taking into account the influence of local thermal processes in the composite structure, in particular, heat generation bursts during a pulse, has been performed. The HTS composite switching times from the superconducting to the normal state have been investigated for various current pulses amplitudes in homogeneous magnetic fields. An experimental verification of the numerical model has been carried out.

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This paper presents a numerical layered 2G HTS tape model with the transport current flowing through it. The simulation is performed by using FEM H-formulation method implemented in the Comsol Multyphysics software. The model provides two cooling modes: cryocooler and liquid nitrogen. LN2 cooling mode provides for a complex hysteresis character of the liquid nitrogen boiling curve and the boiling regimes changing possibility between the stationary and the bubble boiling. The delay of the voltage rising with a transport current above the critical value pulse input is shown in the liquid nitrogen cooling case. The possibility of parameters calculating for current redistribution from the HTS to the stabilizing copper layer is shown, and the stabilizing coating thickness effect on the thermal transition critical current value is studied A comparison with experimental results is carried out.

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