Numerical Simulation of AC Loss in 2G High-Temperature Superconducting Coils with 2D-Axisymmetric Finite Element Model by Magnetic Field Formulation Module

In this paper, numerical simulation of the second generation (2G) high-temperature superconducting coils has been developed in the module of magnetic field formulation with 2D-axisymmetric model. The brevity of expressions and the consistency between the 2D model and 2D-axisymmetric model of this approach make it easier than the method of partial differential equations (PDEs) and magnetic fields module to simulate the high-temperature superconductors. The accuracy of this technique was certified through the comparison with the results of infinite long tape solved by the analytical equation and PDE method. Then, the simulation about a high-temperature superconducting coil with 40 turns was conducted, in which the anisotropic characteristics of 2G tapes expressed with the fitting formulation of J(B, oee integral) was considered. The distribution of current density and magnetic field at different time steps, and the voltage variation for each turn in the coil were studied. It could be seen that the electromagnetic quantities at the inner turns of a coil must be especially noticed. And finally, the AC loss of our model was calculated.