Design of REBCO Fully Superconducting Synchronous Machine Operated at Liquid Nitrogen Temperature for Electric Aircraft

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K20432
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0302:Electrical and electronic engineering and related fields
• Research Institution: Kyushu University
• Principal Investigator: Sasa Hiromasa 九州大学, システム情報科学研究院, 助教 (70906974)
• Project Period (FY): 2021-08-30 – 2024-03-31
• Keywords: 高温超伝導 / 全超伝導同期機 / 電気推進航空機 / 交流損失 / 液体窒素

Outline of Final Research Achievements

We addressed design of fully superconducting synchronous machine, that is, motor and generator, for electric aircraft. For the prevention of serious accidents caused by temperature rise of superconducting windings, the liquid nitrogen which has good property of specific heat is supposed as refregirator of the superconducting machine. We aimed to propose a design method for the superconducting windings in such machine. For that purpose, we measured the AC losses of superconducting tapes in magnetic field by experiments to clarify its property, and we established a method which can estimate the AC loss for various conditions. Moreover, we successfully improved the design method of synchronous machine by using electromagnetic and thermal analysis by introducing the effect of AC loss. Based on the improved method, we proposed a design which the superconduting windings are efficiently cooled.

Free Research Field

超伝導工学、電気工学

Academic Significance and Societal Importance of the Research Achievements

本研究では、全超伝導同期機内の磁界状況を再現した実験により超伝導線材の交流損失特性を明らかにした上で、様々な条件における交流損失を予測することを可能にした。この成果は、全超伝導同期機のみならず、超伝導誘導機など交流環境で使用される様々な超伝導機器にも応用可能であり、超伝導機器の研究開発に広く貢献する成果である。さらに本研究では、電磁界・熱の解析ソフトを用いた同期機設計に交流損失の影響を導入した。交流損失の発生量の低減やその冷却方法は、航空機向け超伝導モータの実用化に向けた最大の課題の一つと言え、本研究で得られた成果を活用することでそれらの解決に向けて一歩前進したと言える。