三次元有限要素法による低損失な同軸多層高温超電導ケーブルの基礎的検討

摘要

本研究では，高温超電導体の非線形特性であるE-J特性rnを考慮した三次元六面体辺要素有限要素法を用いることにrnより，磁束分布の詳細な振る舞いと，電流による各部の導rn電率の変化まで考慮して，通電層2層，シールド層1層かrnら成る同軸多層高温超電導ケーブルの解析を行った。%Controlling the current distribution in each layer of a co-axial multi-layered high-T_c superconducting (HTS) cable uniformly is important in order to realize a compact and large capacity HTS power cable. The phenomenon of current imbalance should be exactly investigated by the analysis, because the current imbalance causes an increase of AC loss. In this paper, 3-D finite element analysis taking account of the nonlinear E-J characteristic is carried out in order to study the AC loss of a co-axial multi-layered HTS power cable with shield layers. The analysis region is considerably reduced by modeling spirally wound superconducting tapes as conductors having an anisotropic conductivity and using the periodic boundary condition. By using this model, AC transport characteristics of the co-axial three-layers cable (composed of two conductor layers and one shield layer) are studied, and the AC loss is investigated. The structure with low AC loss is also discussed.