• 한국초전도ㆍ저온공학회논문지
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• 제1권2호
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• pp.49-53
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• 1999

We fabricated a resistive superconducting fault current limiter (SFCL) with a shunt resistor in order to bypass the transient current at faults. The SFCL consists of a YBCO films coated with an Au layer (10$\Omega$ at room temperature). which is to disperse the heat generated at hot spots in the YBCO films, and a 5$\Omega$ shunt resistor. The minimum quench current of the SFCL was found to be 12.2Apeak. This SFCL successfully controlled the fault current to below 23 Apeak. Which is otherwise to increase up to 103 Apeak. With the shunt resistor, the temperature of the SFCL rose the temperature of the SFCL rose three times slower than without the shunt, whereby the SFCL is protected at high currents.

• 대한전기학회논문지:전력기술부문A
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• 제55권8호
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• pp.329-333
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• 2006

We investigated the quench characteristics of a flux-lock type superconducting fault current limiter (SFCL) depending on the number of the serial connection between the superconducting elements at the subtractive polarity winding of a transformer. The flux-lock type SFCL consists of two coils. The primary coil is wound in parallel to the secondary coil through an iron core, and the secondary coil is connected to the superconducting elements in series. The operation of the flux-lock type SFCL can be divided into the subtractive and the additive polarity windings depending on the winding directions between the primary and secondary coils. In this paper, the analyses of voltage, current, and resistance of superconducting elements in serial connection were performed to increase the power capacity of flux-lock type SFCL. The power burden was reduced through the simultaneous quenching between the superconducting elements. This enabled the flux-lock type SFCL to be easy to increase the capacity of power system.

• Transactions on Electrical and Electronic Materials
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• 제7권2호
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• pp.87-89
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• 2006

We investigated the current limiting characteristics of flux-lock type superconducting fault current limiter(SFCL) according to inductance variation of coil 2. The flux-lock type SFCL consists of two coils. The primary coil is wound in parallel to the secondary coil through an iron core, and the secondary coil is connected to the superconducting element in series. The operation of the flux-lock type SFCL can be divided into the subtractive and the additive polarity winding operations according to the winding directions between the coil 1 and coil 2. The current limiting characteristics in two winding directions were dependent of on the ratio of the number of turns of coil I and coil 2. The fault current increased when the number of turns of coil 2 increased in the subtractive polarity winding. On the contrary, the fault current decreased under the same conditions in case of the additive polarity winding.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.137_138
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• 2009

The increasing of fault current by introducing of the distributed generation(DG) in distribution system disrupts the protective coordination. Therefore, this paper applies the superconducting fault current limiter(SFCL) to solve this problem. The distribution system with DG and SFCL is modeled by EMTP. According to various size of the DG, the fault is simulated and the operating time of overcurrent relay is investigated accoring to the resistance of SFCL.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.10-13
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• 2003

6.6㎸rms/200Arms DC reactor type superconducting fault current limiter (SFCL) has been developed. This paper deals with the manufacture and short-circuit test of the SFCL. DC reactor was the HTS solenoid coil whose inductance was 84mH. AC/DC power converter was performed as the dual-mode operation. The short-term run(1 sec) and short-circuit test of this SFCL was performed successfully. The experimental results have a similar tendency to the simulation results. In short-circuit test, at 2 cycles after the fault, fault current limitation rate was about 30％.

• 조명전기설비학회논문지
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• 제29권7호
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• pp.47-53
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• 2015

As the industrial development in Korea, the power demand is rapidly increased. The power system has been extended and complicated to meet the power demand. However, the fault current increases because the structure of power system reduces the equivalent impedance. One of the solutions to reduce the fault current is Superconducting Fault Current Limiter(SFCL) and the researches of SFCL application have much conducted. In this paper, we used the Circuit Breker Burden Index(CBBI) to select application location of SFCL because the CBBI may consider a fault current of each line. In addition, this paper divided the weight factor used to calculate the CBBI on a case by case basis and analyzed this characteristics through experiment.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.255-258
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• 2003

The hysteresis characteristics of flux-lock reactor, which is an essential component of flux-lock type superconducting fault current limiter (SFCL), was investigated. The hysteresis loss of iron core in flux-lock type SFCL does not happen due to its winding's structure especially in the normal state. From the equivalent circuit for the flux-lock type SFCL and the fault current limiting experiments, the hysteresis curves could be drawn. Through the hysteresis curves together with the fault current level due to the inductance ratio for the 1st and 2nd winding, the increase of the number of turns in the 2nd winding of the flux-lock type SFCL had a role to prevent the iron core from saturation.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2001년도 학술대회 논문집
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• pp.176-177
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• 2001

Three nearly identical superconducting fault current limiters (SFCLs) were connected in series to increase the voltage ratings. A slight difference in the quench starting point of individual SFCL units produced significantly imbalanced power distribution when connected in series. The imbalance was successfully removed by connecting a shunt resistor to one SFCL in parallel. 1.2 kV SFCL was designed with five current limiting elements and two or three shunt resistors.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.334-336
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• 2002

This study is concerned with the operation algorithm and power switch drive circuit for DC Reactor Type High-Tc Superconducting Fault Current Limiter (SFCL). In the case of SFCL, Power switching operation algorithm are very important problem. So, this driving will determine the performance of SFCL. In this paper, we provide a simple algorithm and easy drive circuit. Through experiment we found that ideal is right.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.355-356
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• 2009

In this paper, we investigated the fault current limiting characteristics according to the increase of voltage in the separates three-phase flux-lock type high-Tc superconducting fault current limiter using YBCO CC. The separated three-phase flux-lock type SFCL consists of single-phase flux-phase type SFCL in each phase. Superconductor was using the YBCO CC. To analyze the current limiting characteristics of a three-phase flux-lock type SFCL, the short circuit experiments were carded out fault such as the triple line-to-ground fault. The experimental result shows that fault current limiting characteristics was improved on the high voltage level.