Screening-current-induced magnetic fields and strains in a compact REBCO coil in self field and background field  

作　　者：Yufan Yan Donghui Jiang Peng Song Jeonghwan Park Seungyong Hahn Yunfei Tan Timing Qu 

机构地区：[1]Department of Electrical and Computer Engineering,Seoul National University,Seoul 08826,Republic of Korea [2]State Key Laboratory of Clean and Efficient Turbomachinery Power Equipment,Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China [3]High Magnetic Field Laboratory,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China [4]Wuhan National High Magnetic Field Center,Huazhong University of Science and Technology,Wuhan 430074,China

出　　处：《Superconductivity》2024年第1期35-49,共15页超导（英文）

基　　金：supported by the National MCF Energy R&D Program under Grant No.2022YFE03150103;the National Natural Science Foundation of China(NSFC)under Grant No.52277026;the BK21 FOUR program of the Education and Research Program for Future ICT Pioneers,Seoul National University in 2023.

摘　　要：REBa_(2)Cu_(3)O_(7−x)(REBCO)coated conductors,owing to its high tensile strength and current‐carrying ability in a background field,are widely regarded a promising candidate in high‐field applications.Despite the great potentials,recent studies have highlighted the challenges posed by screening currents,which are featured by a highly nonuniform current distribution in the superconducting layer.In this paper,we report a comprehensive study on the behaviors of screening currents in a compact REBCO coil,specifically the screeningcurrent‐induced magnetic fields and strains.Experiments were carried out in the self‐generated magnetic field and a background field,respectively.In the self‐field condition,the full hysteresis of the magnetic field was obtained by applying current sweeps with repeatedly reversed polarity,as the nominal center field reached 9.17 T with a maximum peak current of 350 A.In a background field of 23.15 T,the insert coil generated a center field of 4.17 T with an applied current of 170 A.Ultimately,a total center field of 32.58 T was achieved before quench.Both the sequential model and the coupled model considering the perpendicular field modification due to conductor deformation are applied.The comparative study shows that,for this coil,the electromagnetic–mechanical coupling plays a trivial role in self‐field conditions up to 9 T.In contrast,with a high axial field dominated by the background field,the coupling effect has a stronger influence on the predicted current and strain distributions.Further discussions regarding the role of background field on the strains in the insert suggest potential design strategies to maximize the total center field.

关 键 词：Electromagnetic-mechanical analysis High‐field insert coil REBCO coated conductor Screening‐current‐induced magnetic field Screening‐current‐induced stress 

分 类 号：TM26[一般工业技术—材料科学与工程]