Study into the cause of property degradation of strands into a cable-in-conduit conductor by kink distortion under the large electromagnetic force

2014 Fiscal Year Final Research Report

• Project/Area Number: 24360103
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Power engineering/Power conversion/Electric machinery
• Research Institution: Tohoku University
• Principal Investigator: MIYAGI DAISUKE 東北大学, 工学(系)研究科(研究院), 准教授 (10346413)
• Co-Investigator(Kenkyū-buntansha): TSUDA Makoto 東北大学, 大学院工学研究科, 教授 (10267411)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: ケーブルインコンジット導体 / 超伝導コイル / 核融合装置 / 偏流 / 循環電流 / 拠り乱れ / 素線変形 / 電磁力

Outline of Final Research Achievements

We investigated influence of unbalanced current among strands on local strand deformation in a cable-in-conduit conductor (CICC). The unbalanced current, which is caused by the non-uniform circulating current induced among strands by external magnetic field and inhomogeneous resistance distribution in a joint, causes the local electromagnetic force. The non-uniform circulating current distribution in the CICC was calculated by contact resistances and inductance of the loop between strands with twist deformation. Our results show that local unbalanced current is improved when the n-th order sub-cable twist pitch is a multiple of all the previous sub-cables twist pitch. We estimated the displacement of a strand on the cable surface using beam length in each triplet and circulating current in each loop. In order to prevent local large displacement of a strand, it is effective to prevent unbalanced current distribution, to improve 0.2% strength-proof, and to shorten the beam length.

Free Research Field

応用電力システム工学，超伝導工学