Fundamental Study of Current Limiting Device using High-Tc Superconductor

本研究旨在探讨高Tc超导限流器之基本特性。本研究探讨了超导元件中电流引起的电阻的出现和消失过程、元件电流、元件温度和外磁场下的电阻特性、电阻的高频特性、大电流下元件的熔断特性等，制作了Y型和Bi型超导限流元件。主要结果如下所述。(1)适用于限流的超导体中出现的电阻是流动电阻和正常导电电阻。(2)提出了一种预先确定限流器件尺寸的方法。(3)研制了一种采用超导元件的情节式限流熔断器。进行了短路试验，在大电流下具有良好的开断特性。(4)Ni粒子在超导体上的Bitter斑图表明钉扎中心与磁通量之间存在一定的关系。

This research is aiming to study the fundamental characteristics of current limiting device using high Tc-superconductor. In this research were investigated the process of appearance and disappearance of resistance due to the current through the superconductor element, resistance characteristics for element current, element temperature and external magnetic field, high frequency characteristics of resistance, fusing characteristics of element for large current and so on. Current limiting elements using Y-type and Bi-type superconductor were fabricated. Main results are described in the following.(1) The resistance appeared in the superconductor which is applicable to current limiting was flow resistance and normal conductive resistance.(2) A methodology to pre-determine the size of current limiting device was indicated.(3) A plot type current limiting fuse using superconductor element was made. Short circuit test was performed and it showed good breaking characteristics for large power current.(4) The Bitter pattern of Ni particle on the superconcuctor suggested that there is some relationship between pinning center and fluxon.