• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.12
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• pp.1067-1072
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• 2009

YBCO coated conductor is named by second generation superconductor tapes. It is different with first generation superconductor tapes. YBCO coated conductor's specific difference with Bi-2223/Ag tape is more strong mechanical durability. This is important role to apply to superconducting machines. For mechanical transforming of YBCO coated conductors, we are using the well designed former. The merit of transformation is several. First, we vary the superconducting characteristics according to mechanical stress. Second, we reduce the volume of superconductor, so we achieve reducing the volume of superconducting machines. On this study, we experiment the transporting current characteristics of one types YBCO coated conductor. YBCO coated conductor with Ie of 70 A and voltage grade of 0.6 V/cm were connected to spiral former to conduct current application test.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.97-100
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• 2004

In this paper, the preparation of BSCCO superconducting wire by electrophoretic deposition method and the effect of suspension medium used with various solvent solutions of ethanol and buthanol for electrophoretic deposition were studied. The preheating technique in vacuum system for the superconducting powders coated on Ag wire was also investigated. As a result, it was confirmed that the preheating technique was very useful to remove the influence of remains affected to the surface conditions of superconducting wire. And the adsorbed solvent solution which was existed between and on the deposited particle surfaces was almost disappeared at the treating conditions of about $10^{-3}$ Torr and around $200^{\circ}C$ in bell-jar system. By measurement of 4-point prove method, the critical current density($J_c$) of BSCCO superconducting wire was obtained at the value of more than $10^4\;A/cm^2$ in liquid $N_2$(77 K, 0 T).

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.280-284
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• 2000

The prototype high-T$_c$ superconducting (HTS) power transmission cables have been designed and fabricated multi layers of spirally wound HTS tapes. The cables were made Bi-2223 based Ag-sheathed HTS tapes, and tested in LN$_2$. Critical currents of 700A dc and better were achieved. The magnetic flux density and field direction were analyzed in the cable configuration. In this paper the results of analysis and tests of HTS power transmission cables were described.

• 한국초전도학회:학술대회논문집
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• v.12
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• pp.78-78
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• 2002

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.2
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• pp.151-156
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• 2003

High temperature superconductor can only be applied against an engineering specofication that has to be determined for each particular application form the design requirements for economic viability and for operation margins in service. However, in order to realize the HTS transformer, it is necessary to establish the high voltage insulation technique in cryogenic temperature. Therefore, the composite insulation of double pancake coil type transformer are described and AC breakdown voltage characteristics of liquid nitrogen(LN$_2$) under HTS pancake coil electrode made by Bi-2223/Ag are studied. The Breakdown of LN$_2$ is dominated electrode shape and distance. The influence of pressure on breakdown voltage is discussed with th different electrode. For the electrical insulation design of turn-to-turn insulation for the HTS transformer, we tested breakdown strength of insulation sheet under varying pressure. And we investigated surface flashover properties of LN$_2$ and complex conition of cryogenic gaseous nitrogen(CGN$_2$) obove a LN$_2$ surface. The surface voltage of GFRP was measured as a function of thickness and electrode distance in LN$_2$ and complex condition of CGN$_2$ above a LN$_2$ surface. this research presented information of electrical insulation design for double pancake coil(DPC) type HTS transformer.