Fabrication and evaluation of conductor cables using Ag-sheathed high-Tc superconductor tapes

我们研究了最有前途的电力传输电缆股线的银护套多芯带材在自场中的交流输运损耗。实验结果用Norris理论解释，对于具有相同临界电流的椭圆超导体，几乎与超导体的几何形状或丝条数无关。灯丝扭曲对e灯丝的影响不显著，但对损耗行为的贡献主要来自磁滞损耗，也不均衡损耗中的电流分布.本文提出了一种新的计算无场芯形状、电流分布和损耗的方法.因此，对于具有任意截面几何形状的直超导带材，Sell场中的AC传输损耗作为电流幅度10的参数。AC运输损失。矩形带在临界电流附近的高10值处表现为薄带超导体，同时显示出逐渐偏离此值 ...更多信息 10的行为被降低。矩形带中宽度与厚度的纵横比的减小使得偏差更加显著。我们用这种方法计算了两种不同灯丝排列的七芯带的交流输运损耗。将计算结果与Bi 2223银包层带材的损耗实验结果进行了比较，发现损耗密度分布的计算结果与实测结果吻合较好。当灯丝数从7增加到37时，灯丝排列对损耗行为的影响被抑制。利用这种方法，我们对以矩形超导带材为股线的单层和多层平行导体电缆模型的损耗进行了数值计算。电缆导体的损耗值受圆柱形线圈架上的带隙或每层中面对面带之间的间隔的强烈影响。结果表明，改进带缆结构，超导芯在电缆导体中的布置对于抑制在交流电流传输下在电缆导体中产生的损耗是重要的。少

We investigated the AC transport losses in self-fields for Ag-sheathed multifilamentary tapes that are the most promising for the strands of power transmission cables. The experimental results are explained by the theory of Norris for an elliptical superconductor with the same critical current, nearly independent of filament number or superconductor geometry. The filament twist neither causes notable influence on the e filaments, although the main contribution to the loss behavior nor equalizes the current distribution in th losses comes from the hysteresis loss.We proposed a new method to calculate the shape of field-free core, the current distribution and. accordingly the AC transport losses in sell fields as a parameter of current amplitude 10 for straight superconductor tapes with the arbitrary sectional geometry. The AC transport losses for. rectangular tapes behave as a thin strip superconductor in high 10 values near critical current, while showing a gradual deviation from this … More behavior as 10 is lowered. A decrease in the aspect ratio of width to thickness in the rectangular tape makes the deviation more remarkable. We applied this method to calculations on the AC transport losses for two kinds of 7-filamentary tapes with different filament arrangements. We compared the results with the experimental behaviors of the losses for Ag-sheathed Bi2223 tapes, and found that the measured losses are explained by the calculated results of loss-density distribution. The influence of filament arrangement on the loss behaviors is suppressed as the filament number increases to 37, from 7.Using this method, we made numerical calculations on the losses for models of parallel-conductors cables composed of a single- or a multi-layer configurations using rectangular superconductor tapes as the strands. The loss values of cable conductors are strongly influenced by the tape gap on a cylindrical former or a separation between the face-to-face tapes in each layer. The results suggest that the improvement of tape and cable structure, i.e., the arrangement of superconducting cores in the cable conductors, is important to suppress the losses generating in the cable conductors under AC current transmission. Less