酸化物超伝導多芯線材の電流一様化による通電損失の低減 新しい線材構造の提案とその電磁特性の理論解析

Abstract

A new-type structure of multifilamentary oxide-superconducting wire and tape is proposed. It is expected that this structure will be effective in reducing transport losses produced when they carry changing currents. The fabrication method of such a wire or tape with low transport losses has more flexibility in the design of its parameters, such as the pitch and the direction of twisting or the number of filament layers, than the existing method does. Theoretical analyses of transport current distributions and resultant transport losses are made for a cylindrical two-layer wire with a twist in the same or the opposite direction for each layer. The theoretical result shows that uniformity in transport current distribution is achieved by optimizing the wire parameters regardless of the twist direction. Moreover, the possibility that the obtained uniformity reduces transport losses by one order compared with the existing type, which has strongly localized current distribution, is theoretically shown for a new multilayer wire or tape.