• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1333-1335
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• 2000

In order to turn on the SCR gate, trigger signal source have to provide appropriate gate current and voltage under the gate rating based on the characteristic of SCR, the nature of load and power. It will be essential design factors such as trigger source impedance, trigger signal occurring, signal time width and turn off conditions. Also minimum gate trigger current is changed with the deterioration of SCR. SCR, which is needed large gate trigger current absolutely, is very important for SCR characteristic test because it causes unstable output in the misfile or makes a trouble to pulse trigger circuits. This paper shows scheme to test the performance of SCR with the precision analyzing mechanism and the changing trend of minimum gate current under the trigger conditions.

• Progress in Superconductivity and Cryogenics
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• v.19 no.2
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• pp.33-37
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• 2017

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. The 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 operator need a counter-measurement for safety, so superconducting fault current limiter (SFCL) has been received attention as effective solutions to reduce the fault current. For the above reasons various type SFCLs have been studied recently. In this paper, operation characteristics and power burden of trigger type SFCL is studied. The trigger type SFCL has been used for real system research in many countries. Another trigger type SFCL (double quench trigger type SFCL) is also studied. For this paper, short circuit test is performed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.7
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• pp.925-930
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• 2013

The fault current of the power transmission system is greater than that of the power distribution system. Therefore, the introduction of superconducting fault current limiter (SFCL) is more needed to reduce the increased fault current. The trigger-type SFCL consists of the high-temperature superconducting element (HTSC), the current limiting reactor (CLR) and the circuit breaker (CB). The trigger-type SFCL can be used to supplement the disadvantages of the resistive-type SFCL. The operation characteristics of the current ratio differential relay which is usually applied to the protection device of the power transmission system are expected to be affected under fault conditions and the applicability of the trigger-type SFCL. In this paper, we analyzed the operating characteristics, by the fault conditions, between the current ratio differential relay for line protection and the trigger-type SFCL in the power transmission system through the PSCAD/EMTDC simulation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.9
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• pp.159-164
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• 2010

We experiment to analyze on current limiting and recovery characteristics of trigger type SFCL as the composition of the contact. Generally, some superconductor of SFCL is relatively largely loaded due to limit the fault current by oneself and recovery time is affected until the fault cleared. However, in the fault, the proposal trigger type SFCL transfer the fault current to current limiting reactor(CLR) using power switch so it could reduce the recovery time and load of the superconductor. However, because of applying the additional power switches, that could generate some power loss. Therefore, to solve this problem, we proposed the composition method of the double contact for a trigger type SFCL and analyzed on current limiting and recovery characteristics for ones.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.1
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• pp.85-89
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• 2009

We investigated the quench characteristics in accordance with increase of turns number of trigger coil and shunt resistance of matrix-type superconducting fault current limiter (SFCL) with $2{\times}3$ array. The matrix-type SFCL consists of the trigger part to apply magnetic field and the current-limiting part to limit fault current. The fault current limiting characteristics according to the increase of magnetic field and applied voltage were nearly same. This is because the application of magnetic field hasn't an affect on total impedance of the SFCL. When turns number of a reactor increased, the voltage difference between two superconducting units in the current-limiting part according was decreased. The resistance difference generated in two superconducting units was also decreased. Therefore, we confirmed that the differences of the critical behaviors between superconducting units were reduced by application of magnetic field. By this results, we could decide the optimum turns number of reactor to apply magnetic field.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.7
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• pp.1050-1060
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• 1994

This paper is a study on the computer simulation of the characteristics of the superconducting fault current limiter. Input variable parameters are apparent power, load resistance value, line resistance value and so on. Initial fault current 2 times larger than the trigger current is required to reduce the switching time of SFCL. The propagation velocity increases abruptly, the transport current is several times larger than the ciritical current. In this paper, the switching time is calculated to be 323$\mu$ sec, and the initial fault current is 19 times larger than the critical current. Because the trigger coils are bifilar winding, they have little impedance in superconducting state. After fault occurred, the limiting coil acts as a superconducting reactor and the trigger coils quench at a critical current. Without the SFCL in the circuit, fault current after the load impedence is shorted might be increased to 1100A. The fault current is, therefore, successfully limited by the superconducting limiting coil to 100A determined by the coil inductance.

• ETRI Journal
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• v.31 no.6
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• pp.725-731
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• 2009

In this paper, electrostatic discharge (ESD) protection circuits with an advanced substrate-triggered NMOS and a gate-substrate-triggered NMOS are proposed to provide low trigger voltage, low leakage current, and fast turn-on speed. The proposed ESD protection devices are designed using 0.13 ${\mu}m$ CMOS technology. The experimental results show that the proposed substrate-triggered NMOS using a bipolar transistor has a low trigger voltage of 5.98 V and a fast turn-on time of 37 ns. The proposed gate-substrate-triggered NMOS has a lower trigger voltage of 5.35 V and low leakage current of 80 pA.

• 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.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.201.2-201.2
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• 2016

The triggered vacuum switch (TVS) is widely used as a high power switch in the field of pulsed power application. TVS can produce current of higher than 100 kA within a microsecond after being triggered. A triggering high voltage pulse generator supplies a high voltage signal to the trigger system to initiate the discharge between a trigger pin and one of main electrode. The trigger system, which consists of a tungsten trigger electrode and cylindrical ceramic insulator around it, is normally installed at the center of main cathode electrode. The discharging characteristics of the trigger system strongly depend on the geometry, electrode material, vacuum pressure and so on. In addition, we especially will focus on the developing a triggering pulse generator, which can vary not only value of voltage but also pulse duration, because its properties gives pivot influences on the TVS discharge. To verify such effects, we made a 3.3 kJ TVS set-up initially. Thus we will discuss some of prominent results from 3.3 kJ TVS system. In parallel we will show on the design of 300 kJ TVS system for the high current in the future.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.4
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• pp.880-884
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• 2011

The matrix-type superconducting fault current limiter (MSFCL) consists of the trigger and current-limiting parts. The trigger part with reactors connected in parallel improves the quenching characteristics by applying the external magnetic field into the superconducting units. The current-limiting part with superconducting units connected in parallel and shunt reactors connected in series limit the fault current when the fault occurs. We developed the integrated reactor with the trigger and the current-limiting parts to apply high external magnetic field into the superconducting units. This was composed of a superconducting unit for the trigger part and two superconducting units for the current-limiting parts. We confirmed that the external magnetic field generated in the MSFCL with an integrated reactor was larger than that of the MSFCL with the separated reactors. So the differences of voltages generated between superconducting units were decreased in the difference according to the increment of the applied voltage. The whole magnitude of the SFCL was reduced because the volume of an integrated reactor could be reduced by one-third than that of the separated reactors. We confirmed that the critical behavior between the superconducting units in the MSFCL with an integrated reactor was more improved than that of the MSFCL with the separated reactors.