Development of Superconducting Cable and Coated Conductors for Electric Propulsion System of Airplane
Teruo Izumi, Kei Shiohara, T. Machi, A. Ibi, K. Nakaoka, Hishiro T. Hirose, Kazuhisa Adachi, T. Nakanishi, Michio Sato, Yuji Aoki, Yasuo Takahashi, Masashi Miura, Hirokazu Hirai, Msayuki Konno, M. Iwakuma
Abstract
The superconducting cable for an electric propulsion system of an airplane was developed using coated conductors (CCs). To lighten the cable-weight, stacked conductors without the center core were employed, leading to the reduction of the diameter and effectively reducing the weight. The cable demonstrated reasonable high <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I<sub>c</sub></i> values for the DC current. Additionally, the cable was revised for loading the AC current. Gaps in the insulators of the craft-papers and spacers were added to separate each phase-conductor. Evaluation of the AC current loading confirmed no degradation at loads greater than 1900 Arms, which is sufficient for a 1 MW propulsion system. A low unit weight of 1.44 kg/kA/m of the cable was achieved. Considering the future goal of a 20 MW system, the performance of the coated conductors was developed to improve the infield values. The long CCs were successfully fabricated by the UTOC-MOD process, which is effective for refining the pinning centers. The pseudo-FFDS cable was confirmed to achieve a high <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">I<sub>c</sub></i> value of 304 A/cm-w at 70 K under 2.5 T. Finally, a light unit weight of 0.35 kg/kA/m for the future cable concept was proposed from the weight analysis.