A Criterion for Determining Stabilizer Thickness of YBCO Coated Conductors Based on Coil Protection
A Criterion for Determining Stabilizer Thickness of YBCO Coated Conductors Based on Coil Protection
复制标题
基于线圈保护的YBCO涂层导体稳定剂厚度确定标准
DOI：
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发表时间：
2007
影响因子：
1.8
通讯作者：
Y. Shiohara
中科院分区：
文献类型：
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作者：
A. Ishiyama;H. Ueda;T. Ando;H. Naka;S. Bamba;Y. Shiohara
本研究的目的是提出一个标准，确定稳定层厚度的YBCO涂层导体。高温超导体（HTSs）中的允许扰动能量密度比低温超导体（LTS）中的大两到三个数量级。另一方面，为了提高高温超导线圈的可靠性和安全性，高温超导线圈系统还需要建立一种保护方案，该方案假设由电源、冷却系统或类似问题中的故障引起的失超。失超会使线圈绕组产生过高的温度或电压;过热可能会导致导体熔化，或者高电压可能会在绕组上穿孔。为了避免YBCO线圈中的这些类型的损坏，必须针对YBCO涂层导体的复杂结构确定合适的稳定剂厚度，所述YBCO涂层导体由在平坦柔性衬底上的高度织构化的薄膜组成。因此，我们从能量转储的角度研究了YBCO涂层导体的适当结构（即，猝灭保护）。基于保护方案，存储在线圈中的磁能转储由外部转储电阻准备作为失超保护，我们推导出一个函数，检查淬火的YBCO线圈在绝热条件下的热平衡，并提出了一个标准使用的功能，以确定适当的稳定剂厚度为YBCO涂层导体。
The purpose of this study is to propose a criterion for determining stabilizer thickness of YBCO coated conductors. The permissible disturbance energy density in high-temperature superconductors (HTSs) is two or three orders of magnitude greater than that in low-temperature superconductors (LTSs). On the other hand, to enhance the reliability and safety of HTS coils, an establishment of a protection scheme assuming a quench caused by a failure in power supply, cooling system or similar problem is also required for HTS coil systems. Quenching produces excessive temperature or voltage in the coil winding; overheating may cause the conductor to meltdown, or high voltage may punch a hole in the winding. To avoid these types of damages in YBCO coils, a suitable stabilizer thickness must be determined for the sophisticated structure of YBCO coated conductors, which are composed of highly textured thin-film on a flat flexible substrate. Therefore, we investigate the appropriate structure for YBCO coated conductors from the perspective of energy dumping (i.e., quench protection). Based on the protection scheme that the stored magnetic energy in the coils is dumped by an external dump resistance prepared as a quench protection, we derive a function that examines the heat balance of a quenching YBCO coil in an adiabatic condition and propose a criterion using the function to determine an appropriate stabilizer thickness for YBCO coated conductors.