@article{01f08d0ab48a4bc1b7432cbdcfb51f8b,
title = "Development of 1-T Class Force-Balanced Helical Coils Using REBCO Tapes",
abstract = "The authors proposed the concept of the force-balanced helical coils (FBC) using high-temperature superconducting (HTS) tapes as a feasibility option for superconducting magnetic energy storage (SMES). Although the FBC can minimize the mechanical stresses induced by the electromagnetic forces, the FBC has three-dimensional complex shapes of helical winding. Therefore, when the tensile strain and the complex bending strain simultaneously apply to the HTS tapes, the critical current of the HTS coils may decrease irreversibly. The objective of this work is to clarify the critical current property of REBCO tapes depending on the applying complex mechanical strain due to the winding process, the winding configuration and the electromagnetic forces through the development of the HTS-FBC. As a first, design parameters of 1-T class FBC using REBCO tapes and coil winding trajectory were introduced, and the authors discussed the normalized critical current of the HTS-FBC for complex uniaxial strain distribution. The authors also reported a development of a helical winding machine whose motion was optimized to prevent from decreasing the critical current of the HTS tapes during winding process.",
keywords = "Force-balanced coil, REBCO coated conductors, SMES, helical coil, high field magnets",
author = "Hiroharu Kamada and Akira Ninomiya and Shinichi Nomura and Tsuyoshi Yagai and Taketsune Nakamura and Hirotaka Chikaraishi",
note = "Funding Information: Manuscript received September 25, 2019; accepted January 15, 2020. Date of publication February 4, 2020; date of current version February 26, 2020. This work was supported in part by the Auspices of the Grants-In-Aid for Scientific Research (B), under Grant 16H04321, and in part by the Meiji University International Research Program. Hiroharu Kamada, Akira Ninomiya, and Shinichi Nomura are with Meiji University, Kawasaki 214-8571, Japan (e-mail: kamada@meiji.ac.jp). Tsuyoshi Yagai is with Sophia University, Chiyoda-ku 102-8554, Japan. Taketsune Nakamura is with Kyoto University, Kyoto 615-8510, Japan. Hirotaka Chikaraishi is with the National Institute for Fusion Science, Toki 509-5292, Japan. Color versions of one or more of the figures in this article are available online at https://ieeexplore.ieee.org. Digital Object Identifier 10.1109/TASC.2020.2971461 Fig. 1. Quasi-toroidal coordinate system on the force-balanced coil. As seen from the side of the torus, the right edge of the HTS tapes is the direction in which the toroidal angle increases, the center line of the HTS tapes is on the neutral axis, and the other side is the left edge of the HTS tapes. Publisher Copyright: {\textcopyright} 2002-2011 IEEE.",
year = "2020",
month = jun,
doi = "10.1109/TASC.2020.2971461",
language = "English",
volume = "30",
journal = "IEEE Transactions on Applied Superconductivity",
issn = "1051-8223",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "4",
}