Investigation on Irregular AC Losses in Large Superconducting Coils

大型超导线圈不规则交流损耗的研究

基本信息

批准号：
15360491
负责人：
HAMAJIMA Takataro
金额：
$ 5.76万
依托单位：
Tohoku University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15360491/
关键词：
AC loss Irregular coupling loss Cable in conduit conductor Long time constant Sub-cable Displacement Contact resistance Strand locations ケーブル・イン・コンジットケーブル・イン・コンジット(CIC)導体

项目摘要

It is found that irregular AC losses in cable-in-conduit superconductors cannot be estimated from short conductor sample test results. Current loops, which must be irregularly formed in the cable, decay with the long time constants, and hence enhance the AC losses.We propose a mechanism forming the long loops. The cable is composed of several staged sub-cables. If one strand on the surface of a sub-cable contacts with the other strand on the surface of the adjacent sub-cable, the two strands should encounter each other again at LCM distance of all staged cable pitches, and thereby result in forming a pair of a long loop. The time constants of these loops are fundamentally described as ratios of their inductances to their contact resistances.In order to estimate the time constants τ=L/R of the long LCM loops, we measured the cross contact resistance between the two strands in LHe. The test results showed that the cross contacting resistances were about 50 μΩ. The results suggest that the time constants are around 0.1 s, which is shorter than the measured time constants of 5 to 100 s. This stems from the fact that the cross contact area, which is estimated about 10 μm in the elastic limit, is very small compared with the line contact area, which is the order of cm.In order to investigate the contact conditions in more detail, We fabricated a cable composed of 81 strands with 40% void fraction, and identified 3-dimensional locations of all strands in the cable. It is found that some loops have several line contacts with more than 10mm. This fact demonstrates that the loops with long time constants should be formed.

发现无法从短导体样品测试结果中估算出电缆超导体的不规则AC损失。当前的环在电缆中必须不规则形成，随着长时间的常数腐烂，从而增强了交流电损失。我们提出了一种形成长循环的机制。该电缆由几个分阶段的子量表组成。如果一条链与相邻亚缆的表面上的另一股链的表面上的一条线，则两条线应在所有分期的电缆俯仰的LCM距离处再次相遇，从而形成一对长环。这些回路的时间常数从根本上描述为其电感与其接触电阻的比率。为了估算长LCM环的时间常数τ= l/r，我们测量了LHE中两条线之间的交叉接触电阻。测试结果表明，交叉接触电阻约为50μΩ。结果表明，时间常数约为0.1 s，比测得的时间常数短于5至100 s。这是从弹性限制中估计约10μm的交叉接触区域与线接触面积相比非常小的事实，这是CM.中的顺序，这是详细调查接触条件的顺序，我们制造了由40％void分数组成的81条电缆，并鉴定出了该电缆中所有链的3维位置。发现某些循环具有多个线路触点，超过10mm。这一事实表明，应形成具有长时间常数的循环。

项目成果

期刊论文数量（25）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

対称性を持ったCIC導体構成の比較

对称 CIC 导体配置的比较

DOI：
发表时间：
2004
期刊：
第71回春季低温工学・超電導学会講演概要集 1
影响因子：
0
作者：
谷貝剛;濱島高太郎;他
通讯作者：
他

Contact condition between strands of a model CIC conductor

CIC 模型导体绞线之间的接触条件

DOI：
发表时间：
2004
期刊：
Abstracts of CSJ Conference Vol.70
影响因子：
0
作者：
Makoto Tsuda;谷貝剛;谷貝剛;Makoto Tsuda;T.Yagai;T.Yagai;M.Tsuda;谷貝剛;高畑一也;津田理;谷貝剛;谷貝剛;津田理;M.Tsuda
通讯作者：
M.Tsuda

Relationship between twist pitch and strand location in large CIC conductor for the ITER-CS Model Coil

ITER-CS 模型线圈的大型 CIC 导体绞合节距与股线位置之间的关系