• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 B
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• pp.741-743
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• 2002

Some different types of joining between two parallel high Tc superconducting tapes were prepared and I-V characteristic curves were obtained at the atmosphere of liquid nitrogen. Resistances in joint parts were estimated from I-V curves. We selected the best jointing method among these methods and its resistance were obtained at 28K. The availability of this joint method for fabricating HTS field coils is discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.229-231
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• 1999

For the first time in Korea, a 30kVA superconducting generator has been designed, developed and successfully tested recently. This is the forerunner of a 1MVA superconducting generator which is currently under development. The paper discusses the structure and manufacturing of a superconducting generator. Helium transfer coupling has 3 passages of the recovered Helium gas and a gas flow control system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 A
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• pp.82-84
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• 1998

The normal zone propagation velocity and minimum quench energy (MQE) of cable-in-conduit conductors (CICC) has been investigated at the different background magnetic fields and supercritical helium pressures. The sample CICC of 2 m in length was fabricated with triplet NbTi/Cu strands inserting into a round stainless-steel tube. The heat pulse disturbance with duration time about 400 ms was acted on the center region of the CICC to quench the strands. The normal zone propagation velocity increased with operating current of the CICC. The measured velocity with respect to operation current could be fitted with numerical results.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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• pp.276-279
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• 2000

When high temperature superconducting tapes is fabricated using the PIT (Powder In Tube) method, the length of HTS tapes is increased more than 500 ${\sim}$ 1,000 times of initial powder packed billet. On mechanical processing, heterogeneous properties between the ceramic superconducting core and Ag/Ag alloy sheath occur the non-uniformity deformation as like sausaging that deteriorate the critical current properties of HTS tapes. In this study, we investigated the workability of Bi-2223/Ag/Ag alloy sheath tapes fabricated by the PIT method involving a number of different mechanical processes, multi drawing and rolling. In order to obtain the high critical current density and high uniformity of Bi-2223/Ag sheath tapes, the influences of powder packing density, drawing die angle and rolling parameters were studied. We found that the roll diameter is an important variable in the rolling process, as critical current of tapes rolled using 250 mm rolls was higher than that using 150 mm rolls.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 학술대회 논문집
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• pp.109-112
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• 2003

The high temperature superconducting YBCO films were deposited on the SrTiO$_3$(100) single crystals to find out the proper deposition conditions of YBCO on biaxially-textured metal substrates. Different sets of the substrate temperature, oxygen partial pressure and laser fluence were used to investigate the effect of deposition conditions on the superconducting properties. The new apparatuses for measuring critical temperature (Tc) and critical current (Ic) were designed and manufactured, which were used to obtain Tc's and Ic's of the deposited films. The accuracy of the new apparatus was confirmed by comparing the results with those from SQUID magnetometer. The results on the YBCO films deposited on single crystal substrates which will be used to get the optimum deposition conditions of YBCO films in the coated conductor, are summarized in this report.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.168-170
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• 2002

Magnetization studies were conducted on a single crystal of $YNi_{2}$$B_{2}$C superconductor. The 17 mg crystal was studied at temperatures T from above $T_{c}$ (15.5 K) to 3 K, in the magnetic fields H // c-axis up to 6 tesla. The crystal exhibited little magnetic irreversibility, with a critical current density $CO_{3}$ ~ $10^{-4}$ $\times$ $CO_{3}$, the depairing current density. Near $T_{c}$, the equilibrium magnetization M was London-like with M $\infty$ In(H). The upper critical field $H_{c2}$ of the single crystal $YNi_{2}$$B_{2}$C was estimated by the several alternative approaches such as standard London limit, Ginzburg-Landau, and Abrikosov relations. The estimated $H_{c2}$values agree relatively well with each other approaches.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 C
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• pp.876-878
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• 1999

Internal tin processed Nb3Sn wires with different diameter were locally heated before reaction heat treatment. Local heating at the intermediate state of drawing process decreased the superconducting properties and workability. When the local heating temperatures were higher than melting point of Sn, non-Cu Jc's decreased significantly.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.156-159
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• 1995

A superconducting power cable is one of the promising ways for transmitting huge electric power efficiently in the future. We performed a conceptual design of 154kV, 3GVA class superconducting power cable. The AC loss of superconductor was estimated by using the Bean model. The cross sectional area of stabilizer was calculated under the adiabatic condition. In this paper, the results of the conceptual design of superconducting power cable is described.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.147-149
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• 1995

The stabilization of the conductor in superconducting power cable is very important from the view point of protection. In this study, critical thicknesses of superconducting layer of $Nb_{3}Sn$ conductor and stabilizer Cu have been estimated under the adiabatic condition. The bending stress of $Nb_{3}Sn$/SUS composite superconducting tape on the curvature radius was also evaluated.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2003년도 High Temperature Superconductivity Vol.XIII
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• pp.14-14
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• 2003