Consideration of magnetizing system aiming for light-weighting of superconducting motor

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04449
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21010:Power engineering-related
• Research Institution: Ashikaga University
• Principal Investigator: YOKOYAMA Kazuya 足利大学, 工学部, 教授 (60313558)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 超伝導バルク体 / 回転機応用 / パルス着磁 / 軟鉄ヨーク / 三次元数値解析

Outline of Final Research Achievements

Aiming to apply superconducting bulk magnets to rotating machines, we study to generate a strong magnetic field by pulsed-field magnetization (PFM) and to reduce the size and weight of the device at the same time. We focused on soft-iron yokes, which were used to expose the bulk to a magnetic field at longer time, and the magnetizing properties when using the conventional disk-shaped yoke and newly fabricated ring- and cross-shaped yokes were evaluated. PFM experiments were carried out by changing the temperatures and the amplitude of applied field. The total magnetic flux per unit weight of the cross-shaped yoke was twice that of the disk-shaped one. Moreover, a three-dimensional numerical model of our bulk PFM system was created and numerical analysis was performed under the same conditions as the experiment. The numerical results reproduced the experimental results, and the magnetization process was successfully visualized.

Free Research Field

応用超伝導

Academic Significance and Societal Importance of the Research Achievements

脱炭素社会のニーズから，大型風力発電の導入，航空機や大型船舶の推進装置の電動化などが検討されている。これらの実用化に向けては装置の小型・軽量化が重要な課題であり，小型な装置で永久磁石や電磁石を超える強い磁場を発生できる超伝導バルク磁石は有効な選択肢の一つである。磁化方法は，回転機の電機子巻線を用いて短時間で着磁できるパルス磁化法が有効な手法であるが，試料の性能を十分引き出すことが難しい問題がある。本研究は磁化装置の一部である軟鉄ヨークの形状を変更するという簡便・安価な手法であり，実用化には有効な手法であると考えられる。また，作成した数値解析モデルを着磁方法の改善等に用いることができる。