• Progress in Superconductivity and Cryogenics
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• v.17 no.3
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• pp.57-61
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• 2015

A Superconducting Fault Current Limiter is an electric power device which limits the fault current immediately in a power grid. The SFCL must be cooled to below the critical temperature of high temperature superconductor modules. In general, they are submerged in sub-cooled liquid nitrogen for their stable thermal characteristics. To cool and maintain the target temperature and pressure of the sub-cooled liquid nitrogen, the cryogenic cooling system should be designed well with a cryocooler and coolant circulation devices. The pressure of the cryostat for the SFCL should be pressurized to suppress the generation of nitrogen bubbles in quench mode of the SFCL. In this study, we tested the performance of the cooling system for the prototype 154 kV SFCL, which consist of a Stirling cryocooler, a subcooling cryostat, a pressure builder and a main cryostat for the SFCL module, to verify the design of the cooling system and the electric performance of the SFCL. The normal operation condition of the main cryostat is 71 K and 500 kPa. This paper presents tests results of the overall cooling system.

• Progress in Superconductivity and Cryogenics
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• v.4 no.1
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• pp.110-113
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• 2002

The high-tc superconducting fault current limiters (SFCL) are studied worldwide to be classified as resistive type or inductive type such as magnetic shielding type and dc reactor type. This Paper deals with an open core type SFCL, a kind of magnetic shielding type SFCL. We manufactured a 30 kVA open core type SFCL. It was modified from the old one with a rated power of 8 kVA. We stacked four superconducting tubes as magnetic shielding material and used the same primary winding as the old one. The experiments were performed with a maximum source voltage of 1 kV. The results show that the fault current in the source voltage of 1 kVrms was reduced to be about 105 Apeak, which was calculated to be about 22 % of the fault current in the system without an SFCL.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.2
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• pp.96-100
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• 2017

In this paper, the flux-lock type superconducting fault current limiter (SFCL) using double quench was suggested and its transient current limiting characteristics were analyzed. The suggested flux-lock type SFCL using double quench consists of two magnetically coupled windings and two $high-T_{c}$ superconducting (HTSC) elements connected in series with each winding. To analyze the transient current limiting characteristics of the flux-lock type SFCL using double quench, the short-circuit tests according to the fault angles, which affect the transient component of the fault current right after the fault occurs, were executed. From the comparative analysis for the short-circuit tests at both $0^{\circ}$ and $90^{\circ}$ fault angles, the useful transient current limiting operations of the suggested flux-lock type SFCL through the double or the single quench occurrence were confirmed.

• Progress in Superconductivity and Cryogenics
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• v.7 no.1
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• pp.25-31
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• 2005

Since the discovery of the high temperature superconductors many researches have been performed for the practical applications of superconductivity technologies in various fields. As results, significant progress has been achieved. Especially, Superconducting Fault Current Limiter (SFCL) offers an attractive means In limit fault current in power systems. HTS resistive type SFCL is based on the ultra fast transition from the superconducting (non resistive) state to the normal (resistive) state by overstepping the critical current density, In this study, the simulation method of resistive type superconducting fault current limiter using EMTDC is proposed and the developed EMTDC model of SFCL is applied to the modeled power network using the Parameters of real system.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.12
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• pp.1111-1117
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• 2008

A transformer type superconducting fault current limiter (SFCL) is one of the fault current limiters which have been proposed to reduce the fault current in the transmission lines. This paper proposes the new circuit configuration of a transformer type SFCL and also investigates the operating characteristics of the transformer type SFCL containig the resistor in the tertiary winding. The proposed SFCL contains the resistor in the tertiary winding. The newly inserted resistor can divert the power which the High-Tc superconducting has to bear. Because the resistor in the tertiary winding relieves the power of the High-Tc superconducting, it is possible that the proposed transformer type SFCL can decrease the more larger fault current than the conventional SFCL with the same High-Tc superconducting. And the cost of the proposed transformer type SFCL can be reduced.

• Journal of Electrical Engineering and Technology
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• v.13 no.2
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• pp.533-539
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• 2018

In this paper, the transformer type superconducting fault current limiter (SFCL) with additionally coupled circuit was suggested and its peak fault current limiting characteristics due to the fault condition to affect the fault current were analyzed through the fault current limiting tests. The suggested transformer type SFCL is basically identical to the previous transformer type SFCL except for the additional coupled circuit. The additional coupled circuit, which consists of the magnetically coupled winding to the primary and the secondary windings together with another superconducting element and is connected in parallel with the secondary winding of the transformer type SFCL, is contributed to the peak fault current limiting operation for the larger transient fault current directly after the fault occurrence. To confirm the fault current limiting operation of the suggested SFCL, the fault current limiting tests of the suggested SFCL were performed and its effective peak fault current limiting characteristics were analyzed through the analysis on the electrical equivalent circuit.

• Progress in Superconductivity and Cryogenics
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• v.21 no.3
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• pp.38-42
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• 2019

To protect the power systems from fault current, the rated protective equipment should be installed. However growth of power system scale and concentration of loads caused the large fault current in power transmission system and distribution system. And capacities of installed protective equipment have been exceeded the due to increase of fault current. This increase is not temporary phenomenon but will be steadily as long as the industry develops. The power system need a counter measurement for safety, so superconducting fault current limiter (SFCL) has been received attention as an effective solutions to reduce the fault current. For the above reasons various type SFCL is studied recently. In this paper, the operational characteristics and power burden of trigger type SFCL is studied. The trigger type SFCL has been used for real system research in many countries. And another trigger type SFCL (double quench trigger type SFCL) is also studied. For this paper, short circuit test is performed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.140-145
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• 2004

In this paper, we analyzed the operational characteristics of the modified DC reactor type SFCL and derived the design condition of superconducting coil to be operated properly as power source as well as fault current limiter. It was confirmed through the simulation for the operation of this SFCL that the modified DC reactor type SFCL could be operated as both the uninterruptible power supply and the fault current limiter by controlling the duty ratio of GTO thyristor bridge.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.172-174
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• 2008

A fault current limitation using fault current limiter(FCL) is very important for power system operation. In recent year, a number of research have been performed and still Progressing about the super conducting fault current limiter(SFCL), To protect the power system effectively from the large fault current, several superconducting fault current limiters proposed. However, there are many problem such as cost, recovery and ac loss. To solve these problems, hybrid superconducting fault current limiter(HSFCL) have been proposed. In this paper, HSFCL are modeled using (Electro Magnetic Transient Program - Restructured Version) EMTP-RV.

• Progress in Superconductivity and Cryogenics
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• v.6 no.1
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• pp.28-31
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• 2004

Since the discovery of the high temperature superconductors, many researches have been performed for the practical applications of superconductivity technologies in various fields. As results. significant progress has been achieved. Especially, Superconducting Fault Current Limiter (SFCL) offers an attractive means to limit fault current in power systems. In order to verify the effectiveness of the SFCL, in this paper, the analysis of fault current and voltage stability assessment in a distribution system are performed by the PSCAD/EMTDC-based simulation method in which a component for resistive type ot SFCL is presented. Through the simulation. the advantage of SFCL application is shown, and the effective parameters of the SFCL are also recommended.