Electromagnetic modeling of REBCO high field coils by the H-formulation

doi:10.1088/0953-2048/28/12/125004

	Electromagnetic modeling of REBCO high field coils by the H-formulation
	Xia, J; Bai, HY; Lu, J; Gavrilin, AV; Zhou, YH; Weijers, HW; Xia, J (reprint author), Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA.
刊名	SUPERCONDUCTOR SCIENCE & TECHNOLOGY
	2015-12
卷号	28 期号:12
关键词	REBCO high field coil REBCO pancake coil shielding effect ac loss electromagnetic modeling superconducting magnet
ISSN号	0953-2048
DOI	10.1088/0953-2048/28/12/125004
文献子类	Article
英文摘要	In this paper, we employ the anisotropic bulk approximation to successfully implement the electromagnetic modeling of superconducting coils wound with rare-earth-barium-copper-oxide (REBCO) tapes based on the H-formulation, in which the field-dependent critical current density and highly nonlinear E-J characteristic are considered. The total number of turns in the stacks of REBCO pancake coils is up to several thousand. We validate the anisotropic bulk model by comparing the ac loss of a small four-pancake coil between the bulk model and the original model which takes the actual thickness of the superconducting layer into account. Then, the anisotropic bulk model is used to investigate the self-field problem of the REBCO prototype coils of the National High Magnetic Field Laboratory 32 T all-superconducting magnet. The field and current density distributions are obtained, and an obvious shielding effect is observed at the top and bottom of the coils. The ac losses in the first and second cycles are calculated. The former is crucial to the design of the cooling system and the latter relates to the routine consumption of the liquid helium. It is found that the ac loss in the first cycle is 2.6 times as large as that in the second cycle. We also study the ac loss dependences on some key parameters (the critical current, n-value and ramp rate of the applied current). It is found that both in the first and second cycles, the ac loss increases with decreasing critical current. Moreover, the influence of the n-value on the ac loss is negligible. In addition, the ac loss decreases logarithmically with increasing ramp rate. However, the average power loss increases linearly with increasing ramp rate. We also compare some analytical estimates with the simulation result for the ac loss of the dual prototype coils. It is found that the results of Bean's slab model are closer to the simulation result. The presented model is a useful tool to help us understand electromagnetic behavior and ac losses in REBCO high field coils. It also provides a basis to analyze the mechanical characteristics in the coils in the future.
学科主题	Physics
出版地	BRISTOL
资助项目	国家自然科学基金项目 ; 国家磁约束核聚变能发展研究专项 ; 国家留学基金委项目 ; 美国国家科学基金项目
项目编号	US National Science Foundation [DMR-0654118, DMR-1157490, DMR-0923070] ; state of Florida ; China Scholarship Council ; National Key Project of Magneto-Constrained Fusion Energy Development Program [2013GB110002] ; Innovative Research Group of the National Natural Science Foundation of China [11421062]
语种	英语
WOS记录号	WOS:000366288100013
资助机构	NSFC ; MOST ; CSC ; US NSF
内容类型	期刊论文
源URL	[http://ir.lzu.edu.cn/handle/262010/182475]
专题	土木工程与力学学院_期刊论文
通讯作者	Xia, J (reprint author), Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA.
推荐引用方式 GB/T 7714	Xia, J,Bai, HY,Lu, J,et al. Electromagnetic modeling of REBCO high field coils by the H-formulation[J]. SUPERCONDUCTOR SCIENCE & TECHNOLOGY,2015,28(12).
APA	Xia, J.,Bai, HY.,Lu, J.,Gavrilin, AV.,Zhou, YH.,...&Xia, J .(2015).Electromagnetic modeling of REBCO high field coils by the H-formulation.SUPERCONDUCTOR SCIENCE & TECHNOLOGY,28(12).
MLA	Xia, J,et al."Electromagnetic modeling of REBCO high field coils by the H-formulation".SUPERCONDUCTOR SCIENCE & TECHNOLOGY 28.12(2015).