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

• 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
• Project Status: Completed (Fiscal Year 2023)
• Budget Amount: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000); Fiscal Year 2022: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2021: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• 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 Research at the Start

地球温暖化防止に向け航空機を電気推進化するにあたり、小型軽量かつ高出力設計が可能な全超伝導同期機の開発が求められる。高出力化や高効率化を目的として液体水素(20K)を用いる構想があるが、落雷事故時に放電や昇温の危険性が高い。安全性の観点から、絶縁耐力に優れる液体窒素(63～77K)での冷却が妥当である。安全性を議論するにあたり、超伝導巻線に発生する交流損失を考慮する必要があるが、その特性は明らかになっていないため、定量的な予測が困難である。本研究では、超伝導線材の交流損失を定量的に予測することを可能にし、液体窒素温度で運転する航空機用の全超伝導同期機について設計指針を示すことを目的とする。

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.

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。

Research Products

• [Journal Article] Effectiveness of REBCO Trapezoidal Armature Coils Used in Superconducting Induction Motors (2024)
  • Author(s): Tsumori Masahiko、Yamasaki Ryoto、Okade Yuta、Miyazaki Hiroshi、Miura Shun、Sasa Hiromasa、Yoshida Koichi、Iwakuma Masataka
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: 34 Issue: 5 Pages: 1-6
  • DOI: 10.1109/tasc.2023.3345300
  • Peer Reviewed
• [Journal Article] Fabrication and Test of a 400 kW-Class Fully Superconducting Synchronous Motor Using REBCO Tape for an Electric Propulsion System (2024)
  • Author(s): Miyazaki H.、Iwakuma M.、Emori Y.、Sasa H.、Yoshida K.、Sato S.、Miura S.、Sagara I.、Suzuki Y.、Konno M.、Hirai H.、Izumi T.
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: 34 Issue: 5 Pages: 1-6
  • DOI: 10.1109/tasc.2023.3345291
  • Peer Reviewed
• [Journal Article] Current Sharing Among Three-Strand Parallel Conductors Composed of REBCO Tapes in Three-Phase Armature Coil Conditions (2024)
  • Author(s): Miura Shun、Nakamura Kazuki、Masuda Yohei、Kawasaki Goki、Miyazaki Hiroshi、Kawagoe Akifumi、Sasa Hiromasa、Yoshida Koichi、Sato Seiki、Iwakuma Masataka
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: 34 Issue: 5 Pages: 1-5
  • DOI: 10.1109/tasc.2024.3352521
  • Peer Reviewed
• [Journal Article] Electromagnetic Design of a REBCO Four-Pole Full-Pitched Armature Coil Composed of Trapezoidal Windings for Fully Superconducting Synchronous Motors (2024)
  • Author(s): Emori Yuki、Miyazaki Hiroshi、Miura Shun、Sasa Hiromasa、Iwakuma Masataka
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: 34 Issue: 5 Pages: 1-5
  • DOI: 10.1109/tasc.2024.3358250
  • Peer Reviewed
• [Journal Article] Current Distributions in Armature Coils Comprising Two Sizes of Racetrack Double-Pancakes with REBCO Striated Tapes (2024)
  • Author(s): Takashima Atsushi、Miyazaki Hiroshi、Miura Shun、Yoshida Koichi、Sato Seiki、Sasa Hiromasa、Iwakuma Masataka
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: 34 Issue: 5 Pages: 1-5
  • DOI: 10.1109/tasc.2024.3356439
  • Peer Reviewed
• [Journal Article] Current Distribution Among Transposed Eight- and 16-Parallel REBa2Cu3Oy Wires in Single-Phase Armature Coils (2024)
  • Author(s): Miura Shun、Kobun Asato、Masuda Yohei、Kawasaki Goki、Miyazaki Hiroshi、Kawagoe Akifumi、Sasa Hiromasa、Yoshida Koichi、Sato Seiki、Iwakuma Masataka
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: 34 Issue: 3 Pages: 1-6
  • DOI: 10.1109/tasc.2024.3356436
  • Peer Reviewed
• [Journal Article] Evaluation of the AC Loss Characteristics of Multifilamentary REBCO Tapes by the Mechanical Scratching of MgO Areas (2024)
  • Author(s): Oishi Ryoma、Jingami Kodai、Miyazaki Hiroshi、Iwakuma Masataka、Miura Shun、Sasa Hiromasa、Yoshida Koichi、Daibo Masanori、Fujita Shinji
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: 34 Issue: 5 Pages: 1-6
  • DOI: 10.1109/tasc.2024.3370097
  • Peer Reviewed
• [Journal Article] AC Loss Estimation Method for REBCO Superconducting Tapes in AC+DC Fields for Field Windings in Fully Superconducting Synchronous Machine for Electric Aircraft (2024)
  • Author(s): Sasa Hiromasa、Jingami Kodai、Oishi Ryoma、Miura Shun、Miyazaki Hiroshi、Iwakuma Masataka
  • Journal Title: Journal of Physics: Conference Series Volume: -
  • Peer Reviewed
• [Journal Article] Current Sharing Among Transposed Three-Parallel REBa2Cu3Oy Tapes in Single-Phase Armature Coils (2023)
  • Author(s): Shun Miura , Asato Kobun , Yohei Masuda, Kazuki Nakamura, Hiroshi Miyazaki , Akifumi Kawagoe , Hiromasa Sasa , Koichi Yoshida , Seiki Sato, and Masataka Iwakuma
  • Journal Title: IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY Volume: 33 Issue: 5 Pages: 5200306-5200306
  • DOI: 10.1109/tasc.2023.3241824
  • Peer Reviewed
• [Journal Article] Basic Concept for Uniform Current Distribution in Parallel Conductors by Introducing a Small Number of Transpositions in REBCO Armature Coils (2023)
  • Author(s): Kobun Asato、Masuda Yohei、Miura Shun、Miyazaki Hiroshi、Yoshida Koichi、Sato Seiki、Sasa Hiromasa、Iwakuma Masataka
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: 33 Issue: 5 Pages: 1-6
  • DOI: 10.1109/tasc.2023.3242621
  • Peer Reviewed
• [Journal Article] Current Distribution of Armature Coils Combining Two Different Sizes of REBCO Racetrack Double Pancakes (2023)
  • Author(s): Takashima Atsushi、Onamyuda Yuki、Kobun Asato、Miyazaki Hiroshi、Kawagoe Akifumi、Miura Shun、Yoshida Koichi、Sato Seiki、Sasa Hiromasa、Iwakuma Masataka
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: 33 Issue: 5 Pages: 1-5
  • DOI: 10.1109/tasc.2023.3241822
  • Peer Reviewed
• [Journal Article] Thermal-Electromagnetic Coupled Analysis Considering AC Losses in REBCO Windings at 65 K of 10 MW Fully-Superconducting Synchronous Generators for Electric Aircraft (2022)
  • Author(s): Sasa Hiromasa、Miura Shun、Miyazaki Hiroshi、Sasayama Teruyoshi、Yoshida Takashi、Yamamoto Kaoru、Iwakuma Masataka、Hase Yoshiji、Sasamori Yuichiro、Honda Hirokazu、Konno Msayuki、Izumi Teruo
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: - Pages: 1-6
  • DOI: 10.1109/tasc.2022.3160660
  • Peer Reviewed / Open Access
• [Journal Article] REBCO Trapezoidal Armature Windings for Superconducting Induction Motors (2022)
  • Author(s): Okade Yuta、Miyazaki Hiroshi、Sasa Hiromasa、Yoshida Koichi、Miura Shun、Sasayama Teruyoshi、Yoshida Takashi、Kawagoe Akifumi、Iwakuma Masataka
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: 32 Issue: 6 Pages: 5201706-5201706
  • DOI: 10.1109/tasc.2022.3160146
  • Peer Reviewed
• [Journal Article] Experimental Evaluation of Current Distribution in Three-Strand Transposed Parallel Conductors Composed of REBCO Superconducting Tapes (2022)
  • Author(s): Omanyuda Yuki、Sasa Hiromasa、Miyazaki Hiroshi、Miura Shun、Iwakuma Masataka
  • Journal Title: IEEE Transactions on Applied Superconductivity Volume: 32 Issue: 6 Pages: 6601105-6601105
  • DOI: 10.1109/tasc.2022.3154338
  • Peer Reviewed
• [Presentation] 大小2種類のREBCOダブルパンケーキコイルを組み合わせた電機子コイルの電流分流特性 (2023)
  • Author(s): 高島 敦史, 宮崎 寛史, 川越 明史, 三浦 峻, 吉田 幸市, 佐藤 誠樹, 佐々 滉太, 岩熊 成卓
  • Organizer: 2023年度春季低温工学・超電導学会
• [Presentation] 電機子コイルにおけるREBa2Cu3Oy並列導体の素線間電流分流の簡易解析手法 (2023)
  • Author(s): 三浦 峻, 公文 麻人, 増田 陽平, 中村 一稀, 宮﨑 寛史, 川越 明史, 吉田 幸市, 佐藤 誠樹, 佐々 滉太, 岩熊 成卓
  • Organizer: 2023年度春季低温工学・超電導学会
• [Presentation] 全節巻き及び 150 度短節巻き超伝導誘導モータの出力密度の比較検討 (2023)
  • Author(s): 藏原昂平，佐々滉太，吉田敬
  • Organizer: 2023年度(第76回)電気・情報関係学会九州支部連合大会
• [Presentation] 4 本並列導体を用いた REBCO 電機子コイルにおける三相通電時の電流分流率の実験的評価 (2023)
  • Author(s): 増田陽平，中村一稀，三浦 峻，宮崎寛史，川越明史，吉田幸市，佐藤誠樹，佐々滉太，岩熊成卓
  • Organizer: 2023年度(第76回)電気・情報関係学会九州支部連合大会
• [Presentation] 並列導体を用いた 2 種類のレーストラックコイルで構成された電機子コイルの電流分流特性 (2023)
  • Author(s): 片岡小春，高島敦史，宮崎寛史，川越明史，三浦 峻，吉田幸市，佐藤誠樹，佐々滉太，岩熊成卓
  • Organizer: 2023年度(第76回)電気・情報関係学会九州支部連合大会
• [Presentation] Current Distribution in Armature Coils Comprising Two Sizes of Racetrack Double-Pancakes with REBCO Striated Tapes (2023)
  • Author(s): A. Takashima, H. Miyazaki, S. Miura, K. Yoshida, S. Sato, H. Sasa, M. Iwakuma
  • Organizer: MT28
  • Int'l Joint Research
• [Presentation] Evaluation of the AC loss characteristics of multifilamentary REBCO tapes by the mechanical scratching of MgO2 areas (2023)
  • Author(s): R. Oishi, K. Jingami, H. Miyazaki, M. Iwakuma, K. Yoshida, S. Miura, H. Sasa, M. Daibo, S. Fujita
  • Organizer: MT28
  • Int'l Joint Research
• [Presentation] Electromagnetic design of a REBCO four-pole full-pitched armature coil composed of trapezoidal windings for fully superconducting synchronous motors (2023)
  • Author(s): Y. Emori, H. Miyazaki, S. Miura, H. Sasa, M. Iwakuma
  • Organizer: MT28
  • Int'l Joint Research
• [Presentation] Effectiveness of REBCO Trapezoidal Armature Coils Used in Superconducting Induction Motors (2023)
  • Author(s): M. Tsumori, R. Yamasaki, Y. Okade, H. Miyazaki, S. Miura, H. Sasa, K. Yoshida, M. Iwakuma
  • Organizer: MT28
  • Int'l Joint Research
• [Presentation] Estimation Method of AC Loss of REBCO Superconducting Tapes in AC+DC Field for Field Windings in Fully Superconducting Synchronous Machine for Electric Aircraft (2023)
  • Author(s): Hiromasa Sasa, Koudai Jingami, Ryoma Oishi, Shun Miura, Hiroshi Miyazaki, Masataka Iwakuma
  • Organizer: ISS2023
  • Int'l Joint Research
• [Presentation] Development of Fully Superconducting Propulsion System for Aircraft with REBCO Tapes (2023)
  • Author(s): M. Iwakuma, H. Miyazaki, S. Miura, H. Sasa, S. Sato, K. Yoshida, Y. Suzuki, I. Sagara, Y. Hase, M. Konno, M. Ohaku, C. Ikeda, H. Honda, Y. Sasamori, T. Izumi, T. Machi, H. Hirose, S. Lee, S. Hasuo, M. Nakamura, H. Hirai, N. Midoh, K. Adachi, Y. Aoki, K. Shiohara, H. Kasahara
  • Organizer: ISS2023
  • Int'l Joint Research / Invited
• [Presentation] Influence of magnetic shields on current distributions among REBCO parallel conductors in single-phase armature windings (2023)
  • Author(s): Shun Miura, Yohei Masuda, Kazuki Nakamura, Goki Kawasaki, Hiroshi Miyazaki, Akifumi Kawagoe, Hiromasa Sasa, Koichi Yoshida, Seiki Sato, Masataka Iwakuma
  • Organizer: ISS2023
  • Int'l Joint Research
• [Presentation] Electromagnetic design for high power density of fully superconducting synchronous motor with through-shaft type field coil for electric aircraft (2023)
  • Author(s): Kaiji Uriu, Masataka Iwakuma, Hiroshi Miyazaki, Shun Miura, Hiromasa Sasa
  • Organizer: ISS2023
  • Int'l Joint Research
• [Presentation] 交流損失予測に基づく電磁界・熱連成解析による電動航空機用REBCO全超伝導同期機の設計 (2023)
  • Author(s): 佐々 滉太, 三浦 峻, 宮﨑 寛史, 岩熊 成卓
  • Organizer: 2023年度秋季低温工学・超電導学会
• [Presentation] Experimental Evaluation of Current Distribution in Armature Coils Composed of REBCO Double Pancakes With Varying Number of Parallel Conductors (2022)
  • Author(s): Asato Kobun, Atsushi Takashima, Koichi Yoshida, Hiromasa Sasa, Shun Miura, Hiroshi Miyazaki, Masataka Iwakuma
  • Organizer: ASC2022
  • Int'l Joint Research
• [Presentation] An armature coil crossed with two different sizes of REBCO racetrack double pancakes (2022)
  • Author(s): Atsushi Takashima, Asato Kobun, Hiromasa Sasa, Koichi Yoshida, Shun Miura, Hiroshi Miyazaki, Akifumi Kawagoe, Masataka Iwakuma
  • Organizer: ASC2022
  • Int'l Joint Research
• [Presentation] Thermal-Electromagnetic Coupled Analysis Considering AC Losses in REBCO Windings at 65 K of 10 MW Fully-Superconducting Synchronous Generators for Electric Aircraft (2021)
  • Author(s): H. Sasa, S. Miura, H. Miyazaki, T. Sasayama, T. Yoshida, K. Yamamoto, M. Iwakuma, Y. Hase, Y. Sasamori, H. Honda, M. Konno, T. Izumi
  • Organizer: International Conference on Magnet Technology 27
  • Int'l Joint Research
• [Presentation] Design Study of 3f-10 MVA-6.9/1.0 kV REBCO Superconducting Transformers with Lightweight and Current-Limiting Function for an E-Aircraft Propulsion System (2021)
  • Author(s): M. Sumida, H. Sasa, S. Miura, H. Miyazaki, M. Iwakuma, M. Konno, T. Izumi
  • Organizer: International Conference on Magnet Technology 27
  • Int'l Joint Research
• [Presentation] Numerical Analysis of 2 MW Fully Superconducting Synchronous Motor for Electric Aircraft Considering AC Loss in Field Winding (2021)
  • Author(s): K. Matsumoto, H. Sasa, S. Miura, K. Matsumoto, H. Miyazaki, T. Yoshida, T. Sasayama, K. Yamamoto, M. Iwakuma, A. Kawagoe, T. IZUMI, Y. Sasamori, H. Honda, M. Konno, Y. Hase
  • Organizer: International Conference on Magnet Technology 27
  • Int'l Joint Research
• [Presentation] Study of REBCO Trapezoidal Armature Windings for Superconducting Induction Motor (2021)
  • Author(s): Y. Okade, H. Miyazaki, H. Sasa, K. Yoshida, S. Miura, T. Sasayama, T. Yoshida, A. Kawagoe, M. Iwakuma
  • Organizer: International Conference on Magnet Technology 27
  • Int'l Joint Research
• [Presentation] Experimental Evaluation of Current Distribution in Three-Strand Transposed Parallel Conductors Composed of REBCO Superconducting Tapes (2021)
  • Author(s): Y. Omanyuda, H. Sasa, H. Miyazaki, S. Miura, M. Iwakuma
  • Organizer: International Conference on Magnet Technology 27
  • Int'l Joint Research
• [Presentation] Estimation of Ac loss for a high-power density 10 MW REBCO superconducting synchronous generator cooled by sub-cooled liquid nitrogen (2021)
  • Author(s): K. Noda, H. Sasa, H. Miyazaki, S. Miura, T. Yoshida, T. Sasayama, M. Iwakuma, A. Kawagoe, T. Izumi, M. Konno, Y. Sasamori, H. Honda, Y. Hase, M. Shutoh
  • Organizer: International Symposium on Superconductivity 2021
  • Int'l Joint Research
• [Presentation] 電気推進航空機用の超伝導誘導モータにおける出力密度のヨーク厚み依存性 (2021)
  • Author(s): 中村 亮太, 佐々 滉太, 吉田 敬
  • Organizer: 2021年度(第74回)電気・情報関係学会九州支部連合大会
• [Presentation] 超伝導誘導モータにおける出力密度のコイルピッチ依存性 (2021)
  • Author(s): 城間 洋人, 中村 亮太, 佐々 滉太, 吉田 敬
  • Organizer: 令和4年電気学会全国大会