A two-dimensional finite element method to calculate the AC loss in superconducting cables, wires and coated conductors

Abstract

Abstract. In order to utilize HTS conductors in AC electrical devices, it is very important to be able to understand the characteristics of HTS materials in the AC electromagnetic conditions and give an accurate estimate of the AC loss. A numerical method is proposed in this paper to estimate the AC loss in superconducting conductors including MgBB 2 wires and YBCO coated conductors. This method is based on solving a set of partial differential equations in which the magnetic field is used as the state variable to get the current and electric field distributions in the cross sections of the conductors and hence the AC loss can be calculated. This method is used to model a single-element and a multi-element MgB 2 B wires. The results demonstrate that the multi-element MgBB 2 wire has a lower AC loss than a single-element one when carrying the same current. The model is also used to simulate YBCO coated conductors by simplifying the superconducting thin tape into a one-dimensional region where the thickness of the coated conductor can be ignored. The results show a good agreement with the measurement.

Modeling Experimental Magnetization Cycles of Thin Superconducting Strips by Finite-Element Simulations

“…In CSMs, J c (B) can be kept constant (Bean [7], [8]) or can be analytically defined (Fixed Pinning [28], Square Root [29], Kim [30], Exponential models [31]). Strictly speaking, the CSM assumption implies that n = ∞, but as a matter of fact, such a condition can be already achieved when n> 500 (i.e., the E-J curve assumes a very steep profile) [32].…”