高温超電導体の輸送電流と位相が異なる交流磁界の交流損失に関する研究

摘要

Recently superconducting cables have been intensively developed and tested in many countries, since they have compactness and low loss compared with conventional copper cables. In a single-phase coaxial cable, the combined fields of an alternating transport current and an in-phase external filed are applied on superconductors. The AC losses measurement results in the single-phase cables are in good agreement with the theory proposed by Carr. However, in three phases electric devices such as a tri-axial cable, the external filed are out-of-phase from the reference transport current. We derive the AC loss theory of the superconductor applied with the ac reference current and the out-of phase ac external fields. It is found that the AC losses depend on the phase angle between the transport current and external fields.%臨界状態モデルを用いて輸送電流と外部磁界 の位相が異なる場合について磁界分布を示し，交 流損失の理論式を導出することで交流損失の評 価方法を提案した。導出した理論式を測定により 妥当性を確認した結果，オーダーレベルの妥当性 を検証することができた。