Research on improving the performance of longitudinal magnetic field DC power transmission cables using nanostructured superconducting wires

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01872
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 31020:Earth resource engineering, Energy sciences-related
• Research Institution: Kyushu Institute of Technology
• Principal Investigator: Kiuchi Masaru 九州工業大学, 大学院情報工学研究院, 准教授 (90304758)
• Co-Investigator(Kenkyū-buntansha): 吉田 隆 名古屋大学, 工学研究科, 教授 (20314049)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 直流電力ケーブル / 臨界電流密度 / 縦磁界効果 / 磁束ピンニング / 電流容量

Outline of Final Research Achievements

In this study, we conducted research from two perspectives to improve the performance of lightweight and compact DC power transmission cables by using the longitudinal magnetic field effect, in which the current capacity is greatly increased by applying a magnetic field parallel to the direction of current flow in superconducting wires. The first was to clarify the mechanism that determines the critical current characteristics of the wires under a longitudinal magnetic field, and the second was to investigate the optimal environment for using the cable. It was found that the introduction of small defects that do not distort the superconducting layer is effective in improving the critical current characteristics under a longitudinal magnetic field. As for the environment for using the cable, it was found that a current capacity twice as high can be achieved when the cable is supercooled by reducing the pressure of liquid nitrogen compared to when it is cooled with liquid nitrogen.

Free Research Field

超伝導応用

Academic Significance and Societal Importance of the Research Achievements

超伝導電力送電には超伝導ケーブル自体のコストだけでなく、付帯設備などの初期コストが必要なため阻害要因となっているが、本研究の新しい技術を利用した直流電力輸送ケーブルは、液体窒素冷却のみでなく、地中に埋設された断熱二重層の管路内の過冷却液体窒素下におけるケーブルの高性能化を明らかにしている。また、このような高性能な電力輸送ケーブルは、現在注目されている小型核融合炉や電気航空機への利用も可能にする。更に、本研究で明らかにした線材の開発が可能になると、高性能化ばかりでなく高密度化も可能になり利用線材の量を減らすことができ、ケーブル作製のコストの低減にも大きく貢献できる。