Design, fabrication and testing of a coated conductor magnet for electrodynamic suspension

2021 ◽  
Author(s):  
Guangtong Ma ◽  
Tianyong Gong ◽  
Ruichen Wang ◽  
Songlin Li ◽  
Xingchao Nie ◽  
...  
Keyword(s):  
Operating Temperature ◽  
Critical Currents ◽  
Cryogenic System ◽  
Coated Conductor ◽  
Mechanical Coupling ◽  
Heat Leakage ◽  
Electromagnetic Calculation ◽  
Electrodynamic Suspension ◽  
Double Pancake ◽  
Hts Magnet

Abstract Coated conductor magnet, as the onboard magnet of the electrodynamic suspension (EDS) train, is deemed promising due to its relatively high operating temperature, low cooling cost, and good mechanical tolerance, making the liquid-helium-free high-temperature superconducting (HTS) EDS train possible. In order to promote the progress of the HTS EDS train, this work aims at designing, fabricating and testing a coated conductor magnet as the onboard magnet of EDS train. The HTS magnet is designed with the comprehensive considerations of the electromagnetic calculation, thermal-mechanical coupling analysis, as well as the heat load estimation. The magnet is conduction-cooled without any coolant. A radiation shield was used to reduce the heat leakage, enabling the cryogenic system to provide a better low-temperature environment for the magnet. Through a deliberate design, the magnet was fabricated, including two HTS coils and the tailored cryogenic system. Afterwards, the electromagnetic and thermal performances of this magnet were tested and analysed in detail. It was proven that the magnet can be cooled to below 15 K; besides, the magnet has been successfully charged to 240 A. Further increase in the current is possible because of the high safe margin of the critical currents for both the HTS magnet and its current lead, although a slight performance degradation was observed on two double-pancake coils inside the magnet. The present study will provide useful implications for the design and application of onboard HTS magnets in EDS train.

Critical Currents of Overdoped Co-evaporated YBCO Coated Conductors

2007 ◽  
Vol 1001 ◽  
Author(s):  
Jens Hänisch ◽  
Jonathan Storer ◽  
Chris Sheehan ◽  
Yates Coulter ◽  
Vladimir Matias
Keyword(s):  
Critical Temperature ◽  
Critical Current Density ◽  
Oxygen Content ◽  
Lattice Spacing ◽  
Surface Coverage ◽  
Critical Currents ◽  
Coated Conductors ◽  
Hole Doping ◽  
Coated Conductor ◽  
Ybco Coated Conductors

AbstractCoated conductor samples, prepared by reactive co-evaporation, are investigated with respect to the hole-doping dependence of the critical current density. The samples are annealed in an atmosphere of variable oxygen content after which critical currents, critical temperature and the c-axis lattice spacing are measured. The lattice spacing increases with decreasing oxygen content, consistent with literature data. These co-evaporated samples show hole overdoped behavior with respect to the maximum Tc. The achievable range of hole doping in these samples seems to depend on surface coverage. Both self-field and in-field Jc at 75.5 K have a maximum in the overdoped region but at less than maximum oxygen content. The reason for the overdoping of these samples is discussed briefly in terms of Y-Ba disorder.

scholarly journals Degradation of the performance of a YBCO-coated conductor double pancake coil due to epoxy impregnation

2010 ◽  
Vol 470 (17-18) ◽  
pp. 674-677 ◽  
Author(s):  
T. Takematsu ◽  
R. Hu ◽  
T. Takao ◽  
Y. Yanagisawa ◽  
H. Nakagome ◽  
...  
Keyword(s):  
Coated Conductor ◽  
Pancake Coil ◽  
Ybco Coated Conductor ◽  
Double Pancake

Pushing Coated Conductor Critical Currents Beyond 1 kA per cm Width: Stacks of YBCO Layers

2011 ◽  
Vol 21 (3) ◽  
pp. 2953-2956 ◽  
Author(s):  
Yehyun Jung ◽  
Chris J. Sheehan ◽  
J. Yates Coulter ◽  
Vladimir Matias ◽  
Dojun Youm
Keyword(s):  
Critical Currents ◽  
Coated Conductor

scholarly journals Dynamic resistance of a high-T c coated conductor wire in a perpendicular magnetic field at 77 K

2021 ◽  
Author(s):  
Zhenan Jiang ◽  
R Toyomoto ◽  
N Amemiya ◽  
X Zhang ◽  
Christopher Bumby
Keyword(s):  
Magnetic Field ◽  
Critical Currents ◽  
Transport Current ◽  
Field Amplitude ◽  
Threshold Field ◽  
Dynamic Resistance ◽  
Coated Conductor ◽  
Flux Flow ◽  
Wide Range ◽  
Perpendicular Field

Superconducting high-Tc coated conductor (CC) wires comprise a ceramic thin film with a large aspect ratio. This geometry can lead to significant dissipative losses when exposed to an alternating magnetic field. Here we report experimental measurements of the 'dynamic resistance' of commercially available SuperPower and Fujikura CC wires in an AC perpendicular field. The onset of dynamic resistance occurs at a threshold field amplitude, which is determined by the total DC transport current and the penetration field of the conductor. We show that the field-dependence of the normalised magnetisation loss provides an unambiguous value for this threshold field at zero transport current. From this insight we then obtain an expression for the dynamic resistance in perpendicular field. This approach implies a linear relationship between dynamic resistance and applied field amplitude, and also between threshold field and transport current and this is consistent with our experimental data. The analytical expression obtained yields values that closely agree with measurements obtained across a wide range of frequencies and transport currents, and for multiple CC wires produced by different wire manufacturers and with significantly differing dimensions and critical currents. We further show that at high transport currents, the measured DC resistance includes an additional nonlinear term which is due to flux-flow resistance incurred by the DC transport current. This occurs once the field-dependent critical current of the wire falls below the DC transport current for part of each field cycle. Our results provide an effective and simple approach to calculating the dynamic resistance of a CC wire, at current and field magnitudes consistent with those expected in superconducting machines. This is the Accepted Manuscript version of an article accepted for publication in 'Superconductor Science and Technology'. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at https://doi.org/10.1088/1361-6668/aa54e5.

Progress towards a low-cost commercial coated conductor

2001 ◽  
Vol 689 ◽  
Author(s):  
Suresh Annavarapu ◽  
Nguyet Nguyen ◽  
Sky Cui ◽  
Urs Schoop ◽  
Cees Thieme ◽  
...  
Keyword(s):  
Critical Current ◽  
High Performance ◽  
Low Cost ◽  
Critical Currents ◽  
Short Length ◽  
Coated Conductor ◽  
High Quality ◽  
Ybco Films ◽  
Performance Levels ◽  
Current Densities

ABSTRACTYBCO films prepared from metal trifluoroacetate (TFA) precursors on oxide-buffered textured non-magnetic substrates have achieved performance levels equaling that on oxide buffered textured Ni substrates. Critical current densities of 0.7 MA/cm2 to 1.0 MA/cm2 have been achieved in 0.4 µm thick YBCO films on short-length of CeO2/YSZ/Y2O3/Ni/Ni-13wt%Cr substrates. High-quality epitaxial buffers comprising a Ni layer, Y2O3 seed, YSZ barrier and CeO2 cap layers have been deposited over meter long tapes of deformation textured Ni and Ni-13%Cr using reel-to-reel processes. High-performance TFA-based YBCO films have been deposited on 0.1 m to 0.3 m lengths of these oxide buffered substrates using reel to reel processes. Critical current densities up to 1.0 MA/cm2 have been achieved in 0.4 µm thick YBCO films on CeO2/YSZ/Y2O3/Ni substrates. Using multiple coats of the metal trifluoroacetate precursors, thicker YBCO films have been demonstrated on oxide buffered substrates. Critical currents in excess of 100A/cm-width have been achieved for 1.2 µm -1.6 µm thick YBCO films on short lengths of CeO2/YSZ/Y2O3/Ni substrates.

Interface Control in All MOD Coated Conductors: Influence on Critical Currents

2005 ◽  
Vol 868 ◽  
Author(s):  
Alberto Pomar ◽  
Mariona Coll ◽  
Andrea Cavallaro ◽  
Jaume Gàzquez ◽  
Narcis Mestres ◽  
...  
Keyword(s):  
Recent Progress ◽  
Critical Currents ◽  
Coated Conductors ◽  
Buffer Layers ◽  
Coated Conductor ◽  
Thermal Treatments ◽  
Interface Quality ◽  
Flat Surfaces ◽  
Interface Control ◽  
Atomically Flat

AbstractIn this work we will report our recent progress in the control of the interface quality between buffer layers and YBCO thin films grown by the trifluoroacetates route (TFA) and how it influences the critical current of the coated conductors. We have mainly focused on vacuum and metalorganic deposited (MOD) fluorite-like CeO2 buffer layers and on MOD perovskite SrTiO3 buffer layers. We will show that for vacuum CeO2 buffer layers, microcracks at the surface can be controlled by the means of thermal treatments. Coated conductors TFA-YBCO/CeO2sputt/YSZ/CeO2/Ni with Jc(77K)˜1MA/cm2 can be grown even in the presence of these microcracks. For MOD SrTiO3 we will show that growing the buffer layer at low temperature reduces surface roughness and multilayers with high critical currents can be achieved. An all-chemical coated conductor has been grown TFA-YBCO/SrTiO3MOD/BaZrO3MOD/NiO-SOE/Ni with promising in-plane texture, Δ φYBCO=6.6°. For MOD CeO2 buffer layers, thermal annealings in oxidizing atmospheres lead to atomically flat surfaces that avoid the typical polycrystalline surfaces observed in MOD CeO2 grown in Ar/H2. High Jc multilayers can be achieved and the first all chemical coated conductor in IBAD tapes TFA-YBCO/CeO2MOD/YSZIBAD/SS has been obtained with Jc(60K)=2.3MA/cm2.

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