Study on Thermal and Electromagnetic Properties of Superconducting Wires for AC Use

交流超导线材的热性能和电磁性能研究

• 批准号: 02452140
• 负责人: ISHIYAMA Atsushi
• 金额: $ 0.83万
• 依托单位: Waseda University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-02452140/
• 关键词: Superconductivity; AC; Stability; Normal-propagation

Superconducting wires with a CuNi matrix for a.c. applications are not fully stabilized and normal transition is easily induced by various disturbances because the CuNi matrix has a high electrical resistivity and a very low thermal conductivity comparing with the properties of copper. Therefore, the thermal and the electromagnetic behavior of such wires during quench is apparently different from that of conventional copper-stabilized composites. To investigate these properties, we consider the effects of temperature gradient in radial direction of wire cross-section and the redistribution of currents at normal front. We measured longitudinal normal-zone propagation velocities of NbTi/CuNi composites wires which have different cooling condition and compared them with analytical results by the three-dimensional finite element method taking into account the redistribution of currents; influence of the transverse electrical conductance on the current sharing in a composite. The analytical … More results agree well with experiments. And in a.c. use of superconductivity we also need to know the thermal and electromagnetic behaviors during such abrupt increase of transport currents as short-circuit current in superconducting transformers, current changing in super-conducting current limiters and current redistribution during quench process in multi-strand cables. We measured the quench current of NbTi/CuNi superconducting wires as a function of a external d.c. magnetic field, the current sweep rate in the range of 10A/s to 100KA/s and the initial current, which is a transport current just before current changing. Experimental data is compared with analytical results by the finite element method taking the magnetic and the thermal diffusion in radial direction of wire cross-section into account. From these results, the mechanism of normal-zone propagation, the quench current degradation and influence of these phenomena on the abnormal quench process with apparent high normal-zone propagation velocity in multi-strand superconducting cables were discussed. Less

交流用CuNi基超导线材由于与铜的性质相比，CuNi基体具有高电阻率和非常低的热导率，因此应用不完全稳定，并且容易由各种干扰引起正常转变。因此，这种丝在淬火过程中的热行为和电磁行为明显不同于传统的铜稳定复合材料。为了研究这些特性，我们考虑了导线横截面径向温度梯度的影响和法向前沿电流的重新分布。我们测量了具有不同冷却条件的NbTi/CuNi复合材料丝的纵向正常区传播速度，并将其与考虑电流再分布的三维有限元法的分析结果进行了比较;横向电导对复合材料中电流共享的影响。分析 ...更多信息 结果与实验符合良好。在AC。利用超导性，我们还需要知道在诸如超导变压器中的短路电流、超导限流器中的电流变化以及多股电缆中的失超过程期间的电流重新分布等传输电流突然增加期间的热行为和电磁行为。我们测量了NbTi/CuNi超导线材的失超电流随外加直流磁场、电流扫描速率（10 A/s ~ 100 KA/s）和初始电流（电流变化前的输运电流）的变化。实验数据与有限元法的分析结果进行了比较，考虑到磁和热扩散的导线横截面的径向方向。根据这些结果，讨论了超导电缆正常区传播的机理、失超电流的衰减以及这些现象对正常区传播速度明显增大的异常失超过程的影响。少

项目成果

T.Onuki: "Design of the Hybrid Magnet in a Magnetic Levitation System using the Boundary Element Method" Int.Journal of Applied Electomagnetic in materials. 1. 263-269 (1990)

T.Onuki：“使用边界元法设计磁悬浮系统中的混合磁体”国际材料应用电磁学杂志。

津田 理(石山 敦士): "高抵抗マトリクス超電導線の不安定性について" 電気学会静止器研究会資料. SAー91ー48. 31-39 (1991)

Osamu Tsuda (Atsushi Ishiyama)：“高电阻基体超导线材的不稳定性”IEEJ 固定研究组材料 SA-91-39 (1991)。

T.Onuki: "Novel Boundary Element Formulation in Hybrid FE-BE Method for Electromagnetic Field Conputations" IEEE Trans.on MAGNETICS. (1992)

T.Onuki：“用于电磁场计算的混合 FE-BE 方法中的新型边界元公式”IEEE Trans.on MAGNETICS。

小貫 天: "角筒型リニア誘導モ-タの縁効果とスロットごと給電方式の検討" 電気学会論文誌D. Vol 110. 807-813 (1990)

十大贯：《矩形圆柱直线感应电动机的边缘效应和逐槽供电系统的研究》日本电气工程师学会会刊D.卷110.807-813（1990）

A.Ishiyama: "Prediction of Quench Process in High-Perfoumance Adiabatic Superconductiong Magnets" Memories of the School of Science & Engineering. 55. (1992)

A.Ishiyama：“高性能绝热超导磁体淬火过程的预测”理学院的回忆