Models for optimization and AC Losses Analysis in a 2G HTS Cable

Abstract

Finite element method (FEM) for both linear and nonlinear cases is widely used for solving time-dependent problems related to the geometrical configuration of electrical HTS devices and AC losses. This paper presents our FEM models used in the development of the HTS cables. Transient 3D FEM models have been developed for optimization of both coaxial and triaxial 2G HTS cables. In these models, only linear magnetic materials are considered. The transient 2D FEM model was developed and used for the calculation of AC losses in the cables made from 2G HTS tapes. The 2G HTS layer of the tape has strong nonlinearity between resistivity and current density and requires careful modeling. Also, it is important to determine the parameters in an empirical expression that describes the critical current density of the 2G HTS layer dependence from the vector magnetic field and its non-uniformity across the tape width.