Numerical Analysis of Electromagnetic Properties of Next-Generation Conductor using YBCO Superconducting Film

本研究是关于YBCO涂层导体有望成为下一代超导线材，旨在开发数值分析工具来详细研究该超导体的电磁性能，如交流损耗。1.数值分析工具的开发通过参加国际国内会议和文献检索，对YBCO薄膜超导导线和故障限流器的研究开发现状进行了综述，收集和整理了可用于YBCO超导体建模的最新信息和数据。在此基础上，开发了利用高性能计算机研究超导体中复杂电磁现象的数值分析工具。特别是提高了分析工具的计算效率，包括E-J特性、S-N跃迁、电磁场和热场与电路的耦合问题等。2.测量了YBCO薄膜的基本电磁性能，并与数值分析结果进行了比较。3.数值分析了YBCO超导体的电磁性能。3.数值分析了YBCO超导体的超导电流分布和交流损耗，重点分析了它们与n值、外加磁场、超导膜宽度等的关系，并研究了YBCO多导体排列和限流元件的电磁特性。通过数值分析，研究了交流损耗的基本特性，以及平面平行和层叠布置的交流损耗特性的差异。由此解释了YBCO超导线材的多导体排列与交流损耗特性之间的关系。

This study was concerned with YBCO coated conductor expected as next-generation superconducting wire and aimed at developing numerical analysis tools to investigate electromagnetic properties of the superconductor, such as AC losses, in detail. The following results were obtained.1.Development of numerical analysis toolsStatus of research and development of superconducting wire and fault current limiters using YBCO film was surveyed through participation in international and domestic conferences and literature search, and latest information and data that can be used for modeling of YBCO superconductor were collected and organized. Based on them, numerical analysis tools were developed for studying complicated electromagnetic phenomena in superconductor using high-performance computers. In particular, improvement of computation efficiency of the analysis tools including E-J characteristics, S-N transition, coupled problems of electromagnetic and thermal fields with electric circuits, etc. was performed.2.Measurement of fundamental electromagnetic properties of YBCO filmBasic electromagnetic properties of a small piece of YBCO superconducting film were measured for comparison with numerical analysis results.3.Numerical analysis of electromagnetic properties of YBCO superconductorSuperconducting current distribution and AC losses in YBCO superconducting wire were analyzed with the emphasis on their dependence on n-value, external magnetic field, superconducting film width, etc. Electromagnetic characteristics of YBCO multi-conductor arrangement and fault current limiting elements were also studied. Fundamental characteristics of AC losses, the difference in AC loss characteristics between the arrangements of planar parallel and layer stack were studied by numerical analysis. From these results the relation between multi-conductor arrangements of YBCO superconducting wires and AC loss characteristics was explained.