• 전기학회논문지
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• 제62권9호
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• pp.1313-1317
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• 2013

With increasing demand of power, the equipment of power system is enlarging and the absolute capacity is going up. As a result, when a fault occurs, the fault current is consistently increasing. Therefore, I suggested some solution for limiting the fault current more efficiently. This study shows the characteristics of superconducting limiting elements and normal conducting elements combined with a transformer. We performed a short-circuit test about the fault current by using SCR switching control system operated from a CT. When short circuit accidents happened in the secondary side of a transformer, fault currents flowed and a SCR switching control system was operated. It resulted in a decrease of the fault current in the limited elements of third winding connected in parallel. For this test, we used YBCO thin films and normal conducting elements as the limited elements. Within a cycle, a superconducting fault current limiter with YBCO thin films reduced more than 90% of fault current because the resistance of superconducting elements sustainedly grew. On the other hand, the limiter with normal conductors limited as much as a set value because its resistance characteristic was linear. Consequently, in case of the limiter with superconductor, limiting range of the circuit was wide but the range of protective detection was undefined. In contrast, as for the limiter with normal conductors, limiting range and protection duty were appropriate.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2000년도 KIASC Conference 2000 / 2000년도 학술대회 논문집
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• pp.154-157
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• 2000

Superconducting tape easily can applied to distribution of electricity. It designs basic model of Saturable Reactor type Fault Current Limiter which used superconducting tape, and observes a specific character by means of simulation. Saturable Reactor type Fault Current Limiter is not influenced by saturation of Magnet core appeared in Induction Fault Current Limiter, because it exploit saturation of Iron core. But, it is possible that superconducting tape quenched when AC current flow to superconducting tape which biased DC voltage.

• 한국전기전자재료학회논문지
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• 제24권1호
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• pp.47-51
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• 2011

The superconducting fault current limiter (SFCL) with a peak current limiting function according to the initial fault current with the different amplitudes was suggested. The proposed SFCL, which consists of two limiting components, causes only the first superconducting element among two limiting components to be quenched in case that the initial fault current with the lower peak amplitude happens. On the other hand, the initial fault current with the higher peak amplitude makes both the superconducting elements of two limiting components to be quenched, which contributes to the peak current limiting function of the SFCL. To confirm the fault current limiting operation of the proposed SFCL, the short-circuit tests of the SFCL according to the fault angle were carried out and its effective fault current limiting operations could be discussed.

• 한국전기전자재료학회논문지
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• 제29권8호
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• pp.499-504
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• 2016

In this paper, we analyzed the operational characteristics of the fault current limiting according to the amplitude of the fault current for the transformer type superconducting fault current limiter (SFCL). If the fault current happens, the superconducting element connected to the secondary coil is occurred quench and the fault current is limited. When the larger fault current occurs, the superconducting element connected to the third coil is occurred additional quench and the peak fault current is limited. We found that the fault current can be more effectively controlled through the analysis of the fault current limiting and the short-circuit tests.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 춘계학술대회 논문집
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• pp.8-8
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• 2010

In this paper, the limiting characteristics of the fault current in a power system with a superconducting fault current limiter(SFCL) applied into neutral line of main transformer in a distribution power line were analyzed. The SFCL applied into the neutral line of main transformer power system can limit the unsymmetrical fault current from the single-line ground fault or the double-line ground fault. In addition, it could be decreased a number of SFCL and a load. This method could be expected to reduction of a power loss in the neutral line, because of a neutral line current is zero in ordinary times.

• 조명전기설비학회논문지
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• 제25권9호
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• pp.44-49
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• 2011

Due to increase of fault current, various superconducting fault current limiter (SFCL) are researched. We studied a power distribution system with SFCL. Along the way, we knew characteristics of fault current according to a distance from substation to fault point. Fault current is reduced by distance`s increase from substation. Also, SFCL.s effects are decreased by distance too. Therefore, we analyzed the fault current by a distance from substation to fault point when a SFCL was applied into a power distribution system. We simulated using a PSCAD/EMTDC.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.300-302
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• 2002

In this paper the high-speed fault current detector for superconducting fault current limiter is described. Detecting and interrupting the fault currents as quickly as possible is required in order not to exceed the thermal capacity of superconducting fault current limiter. A detecting method of an instantaneous fault current magnitude is adopted in the equipment described in this paper and a current signal through an analog/digital(A/D) converter would be compared with the reference in the digital signal processor(DSP). Around 20ms has elapsed for detecting the fault current. It is necessary to establish the appropriate trade-off between the reliability and detection speed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.181-183
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• 1996

A novel model of an inductive superconducting fault current limiter with an inductive superconducting fault current limiter with the air-gap core was fabricated and tested. If its impedance is not high enough to limit the fault current, then destructive damage occurs in the power system. We attained a magnetic saturation under higher current by an effective air gap introduced in the core. The fault current was successfully limited to two times as much as the nominal current at a 60 Hz source having an effective voltage of 70 V. The fault current flowing under such conditions can be limited to a desired value without any fault current peak within 1/4 cycles.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.119-121
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• 1995

This paper is a study on inductive superconducting fault current limiter design.. We have created simulation for an imaginery power system with inductive superconducting fault current limiter. Then input variables for characteristic analysis and actual manufacturing, and output variables for design results was assigned. Using the results from these variables, the design criterion was determined which was fed into concept design arising from characteristic analysis to determine the inductance of limiting coil and normal state resistance value of triggering coil. These result was put back into design details to finally give out the design result for inductive superconducting fault current limiter.

• 한국전기전자재료학회논문지
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• 제24권2호
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• pp.141-146
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• 2011

When the current of the superconducting element exceeds its critical current by the fault occurrence, the quench of the high-$T_C$ superconducting fault current limiter (HTSC) comprising the flux-lock type superconducting fault current limiter (SFCL) occurs. Simultaneously, the magnetic flux in the iron core induces the voltage in each coil, which contributes to limit the fault current. In this paper, the fault current limiting characteristics of the flux-lock type SFCL as well as the load voltage sag suppressing characteristics according to the flux-lock type SFCL's winding direction were investigated. To confirm the fault current limiting and the voltage sag suppressing characteristics of the this SFCL, the short-circuit tests for the simulated power system with the flux-lock type SFCL were carried out. The flux-lock type SFCL designed with the additive polarity winding was shown to perform more effective fault current limiting and load voltage sag suppressing operations through the fast quench occurrence right after the fault occurs and the fast recovery operation after the fault removes than the flux-lock type SFCL designed with the subtractive polarity winding.