• Proceedings of the KIEE Conference
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• summer
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• pp.1130-1132
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• 2004

In this paper, we investigated the operational characteristics of the fault current limiting in the The flux-lock type high-Tc superconducting fault current limiter. The flux-lock type high-Tc superconducting fault current limiter was consisted of primary and secondary copper coils that flux was locked on iron core and YBCO thin film. The operational characteristic of a flux-lock type SFCL dependent on winding direction of coil 1 and coil 2, and the number of turns of coil 1 and coil 2, inductances of the coils, saturation in iron core, the properties of superconducting element etc. In this cases, we investigated the fault currents limiting characteristics of the flux-lock type SFCL when winding direction of coil 1 and coil 2 was subtractive polarity winding.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.12a
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• pp.112-113
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• 2006

The operational characteristics of the integrated three-phase flux-lock type superconducting fault current limiter (SFCL) were analyzed. The suggested three-phase SFCL consisted of a three-phase flux-lock reactor and three high-$T_c$ superconducting (HTSC) elements. The former has three windings wound on an iron core, each of which has the same turn's ratio between coil 1 and coil 2. The latter are connected in series with coil 2 of each phase. The integrated three-phase flux-lock type SFCL showed the operational characteristics that the fault phase could affect the sound phase, which resulted in quenching the HTSC element in the sound phase. Through the computer simulation applying numerical analysis for its three-phase equivalent circuit, the fault current limiting characteristics of the integrated three-phase flux-lock type SFCL according to the ground fault types were compared.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.251-252
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• 2006

As one of methods to increase the voltage rating of the flux-lock type SFCL, the fault current limiting characteristics of the flux-lock type SFCL with HTSC elements connected in series were analyzed. The initial fault current amplitudes in two SFCLs with the series connection of two HTSC elements and with single HTSC element were the same. In addition, the resistance amplitude of each HTSC element in SFCL with the series connection of two HTSC elements had the similar one in SFCL with single HTSC element. With increase of applying voltage, the unbalance of voltage between two HTSC elements in SFCL with the series connection of two HTSC elements disappeared.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1187-1189
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• 1995

The paper is concerned with the pre-arcing behavior of rapid current limiting fuselink using copper as a melting element. The phenomenon is faced by a numerical simulation(especially, FDM is applicated) of the melting element. Through the results, we can know the trends of the I-t characteristics and temperature distribution along the x axis for different fuselink shapes with circular, rectangular, and skew restriction type respectively, to be good for designing the optimal element.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.229-230
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• 2007

We investigated the quench characteristics of a superconducting element, two superconducting elements in order to increase the current capacity of flux lock type SFCL. The flux-lock type SFCL consisted of the transformer with a primary winding and a secondary winding connected in parallel, and the superconducting element was connected with secondary winding in series. The applied voltage at that time was 160 ${\sqrt{3}}$. We found that the parallel connection between the superconducting elements increased the power capacity and let quench characteristics improve through their mutual linkage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05b
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• pp.141-144
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• 2002

We present current limiting properties of 1.2kV/70A superconducting fault current limiter based on YBCO thin films. This is consisted of 6 wafers (3 parallel ${\times}$ 2 serial connection) with 4 inch-diameter YBCO thin film. The quench current Iq of the switching elements vary between 33.9 and 35.6 A. Within the difference of 0.5 A in the sum of quench current Iq in two stacks, the serial connection of the stacks showed the simultaneous quench behavior in applied power of 1.2 kV /70 A.

• Transactions on Electrical and Electronic Materials
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• v.6 no.4
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• pp.159-163
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• 2005

We analyzed the fault current limiting characteristics of a flux-lock type $high-T_c$ super­conducting fault current limiter (HTSC-FCL) using series resonance between capacitor for series resonance and magnetic field coil which was installed in coil 3. The capacitor for the series resonance in the flux-lock type HTSC-FCL was inserted in series with the magnetic field coil to apply enough magnetic field into HTSC element, which resulted in higher resistance of HTSC element. However, the impedance of the flux lock type HTSC-FCL has started to decrease since the current of coil 3 exceeded one of coil 2 after a fault accident. The decrease in the impedance of the FCL causes the line current to increase and, if continues, the capacitor for the series resonance to be destructed. To avoid this operation, the flux-lock type HTSC-FCL requires an additional device such as fault current interrupter or control circuit for magnetic field. From the experimental results, we investigated the parameter range where the operation as mentioned above for the designed flux-lock type HTSC-FCL using series resonance occurred.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.10
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• pp.788-792
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• 2010

The yttrium-barium-copper-oxide (YBCO) coated conductor, which supplement the fault of the existing superconducting current-limit materials YBCO thin film, bismuth-strontium-calcium-copper-oxide(BSCCO) wire and bulk, has been improved its mechanical weakness and has high index; hence, after quench YBCO coated conductor could limit the fault current effectively because of fast resistance occurrence speed. Furthermore, it has wide applicable area as an current limit material because it shows different resistance occurrence tendency by the thickness and kind of stabilization material sputtered on the superconducting layer. Therefore, many researchers are carrying out the study of application of YBCO coated conductor to superconducting fault current limiter (SFCL) for making high quality current limit element, based on resistance type. On the other hand, the study for other type except resistance type has been rarely conducted for the application of YBCO coated conductor to SFCL as an current limit element. Consequently, in this study, YBCO coated conductor with different stabilization layer Cu and Stainless steel, is applied to SFCL using iron core and coil, and examine the many index points as an current limit element, such as current limit characteristic, the tendency of resistance occurrence, response time, the temperature trend for stability.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.790-792
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• 2002

The resistive type superconducting fault current limiter(SFCL) is a current limiter using the Quench mechanism of superconductors. When Quench occurs in superconductors, the resistance of superconductors increases abruptly. In order to increase SFCL capacity, current limiting elements were connected in series. If the Quench current of each element was different, voltage distribution was imbalanced. This imbalance could be removed by arrangement including series and parallel connection of elements. Based on this result, an SFCL of 1.8kV/50A was designed and experimented, expecially, in terms of increasing the voltage rating.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.612-615
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• 2015

This paper proposed an high-speed superconducting fault current limiter (H-SFCL). The proposed H-SFCL functioned the initial fault current could be covered by the SFCL and the continued fault current after the one-cycle from fault occurrence could be controlled current-limiting-element of the normal conduction. To investigate the operation characteristics of the H-SFCL, a simulation power system was constructed, and a single line-to-ground fault was occurred. As a result, the H-SFCL limited the fault current by more than about 70%, and it was confirmed that the electric power burden was reduced compared to the SFCL that consisted only of superconductors.