• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.1909-1913
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• 2014

In this study, a superconducting fault current limiter (SFCL) having two magnetic paths was proposed, and its current limiting characteristics were analyzed. For the SFCL to effectively perform the current limiting operation, it must be designed considering the magnetic saturation of the E-I core. Further, the influence of the magnetic flux on its peak current limiting characteristics was investigated. In addition, the magnetic flux curves of the SFCL obtained from the fault current limiting experiments were analyzed, and the subtractive polarity winding case was observed to not only further reduce the saturation potential of the core but also perform the peak current limiting functions well when compared with the additive polarity winding case.

• 조명전기설비학회논문지
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• 제22권1호
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• pp.113-117
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• 2008

본 논문에서는 결선방향에 따른 자속구속형 전류제한기의 전류제한 및 회 특성에 대해 분석하였다. 자속구속형 초전도 한류기는 초전도 소자와 직렬로 연결된 2차 권선과 병렬로 연결된 1 2차 권선으로 구성되어 있다. 1 2차 권선의 결선방향에 따른 가극 결선과 가극 결선을 갖는 자속구속형 전류제한기를 저항형 전류제한기와 비교하여 분석하였다. 전류제한 및 회복특성은 1 2차 권선의 결선방향에 의존한다. 가극 결선을 갖는 자속구속형 전류제한기의 퀜치시간은 감극 결선이나 저항형 전류제한기보다 더 빠르다는 것을 확인하였다. 초전도 소자에서 소비되는 에너지는 $W= VIt=I^2Rt$으로 표현할 수 있다. 결선 방향에 따라 초전도 소자에서 소비되는 에너지의 차이는 초전도 소자에서 부담하는 전압의 차이 때문이라는 것을 확인할 수 있었다.

• 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.

• 한국전기전자재료학회논문지
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• 제18권4호
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• pp.363-369
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• 2005

we compared the operating characteristics between flux-lock type and resistive type superconducting fault current limiters(SFCLs). Flux-lock type SFCL consists of two coils, which are wound in parallel each other through an iron core, and a high-Tc superconducting(HTSC) element is connected with coil 2 in series. The the flux-lock type SFCL can be divided into the subtractive polarity winding and the additive polarity winding operations according to the winding directions between the coil 1 and coil 2. It was confirmed from experiments that flux-lock type SFCL could improve both the quench characteristics and the transport capacity compared to the resistive type SFCL, which means, the independent operation of HTSC element.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.281-283
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• 2008

The superconducting fault current limiter (SFCL) using magnetic coupling of two coils with series connection, which was suggested by us, has the merit to increase the operational current and the limiting impedance of the SFCL through the adjustment of the inductance ratio and the winding direction of two coils. In addition, the recovery characteristics of the SFCL is affected by the winding direction of two coils as well as two coils' inductance ratio. In this paper, the fault current limiting and recovery characteristics of a SFCL using magnetic coupling of two coils with series connection were analyzed. Through the analysis based on the experimental results, the recovery characteristics and the current limiting characteristics of the SFCL were confirmed to be improved more in case of the additive polarity winding.

• 한국전기전자재료학회논문지
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• 제22권8호
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• pp.694-697
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• 2009

The separated three-phase flux-coupling type superconducting fault current limiter(SFCL) is composed of a series transformer and superconducting unit of the YBCO coated conductor. The primary and secondary coils in the transformer were wound in series each other through an iron core and the YBCO coated conductor was connected with secondary coil in parallel. In this paper, we investigated the current limiting characteristics through winding number of coil 2 and winding direction in the flux-coupling type SFCL. Through the analysis, it was shown that additive polarity condition and lower winding number of coil 2 have advantaged from the point of view of fault current limiting and burned of YBCO coated conductor.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2006년도 High Temperature Superconductivity Vol.XVI
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• pp.77-77
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• 2006

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2005년도 High Temperature Superconductivity Vol.XV
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• pp.95-95
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• 2005

• 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.

• 한국전기전자재료학회논문지
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• 제22권6호
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• pp.522-525
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• 2009

We investigated the fault current characteristics of the separates three-phase flux-lock type superconducting fault current limiter(SFCL) according to the variation of inductances. The single-phase flux-lock type SFCL consists of two coils. The primary coil is wound in parallel to the secondary coil on an iron core. And superconductor is series connected on secondary coil. Superconductor is using the YBCO coated conductor. The separated three-phase flux-lock type SFCL consists of single-phase flux-phase type SFCL in each phase. To analyze the current limiting characteristics of a three-phase flux-lock type SFCL, the short circuit experiments were carried out fault such as the triple line-to-ground fault. The experimental result shows that fault current limiting characteristics of additive polarity winding was better than subtractive polarity winding and when the inductances of coil 2 was lower, resistances of YBCO CC was more generated.