Numerical simulations of the alternating current loss in round high-temperature superconducting wire with a hole defect

This paper presents a finite element model to solve the electromagnetic behavior and the AC loss in round high-temperature superconducting wire with a hole defect both in external field condition and self-field condition. The hole defect is assumed to be infinitely long along the wire. The model is based on the H formulation and the highly nonlinear E - J characteristic. The simulation results for the round superconducting wire with a hole defect and the one without defect are compared. It is found that the existence of the hole defect causes small reduction for the magnetization AC loss and large enhancement for the transport AC loss. The influences of the position and shape of the hole on the AC loss are also investigated. We find that the AC loss in external field condition decreases when the hole defect moves towards the edge of the superconducting wire from its center. However, the feature is opposite in self-field condition. Meanwhile, the influence of the shape of the hole on the AC loss is not strong in both conditions. (C) 2013 AIP Publishing LLC.