• 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.

• Journal of Electrical Engineering and Technology
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• 제3권2호
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• pp.213-217
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• 2008

The flux-lock type superconducting fault current limiter(SFCL) can apply the magnetic field into the high-$T_C$ superconducting(HTSC) element by adopting the magnetic field coil in its third winding. To apply the magnetic field into the HTSC element effectively, the capacitor for LC resonance is connected in series with the magnetic field coil. However, the current waveform of third winding for the application of the magnetic field is affected by the LC resonance condition for the frequency of the source voltage and can affect the waveform of the limited fault current. In this paper, the current waveform of the third winding in the flux-lock type SFCL according to LC resonance condition during a fault period was analyzed. From the differential equation for its electrical circuit, the current equation of the third winding was derived and described with the natural frequency and the damping ratio as design parameters. Through the analysis according to the design parameters of the third winding, the waveform of the limited fault current was confirmed to be influenced by the current waveform of the third winding and the design condition for the stable fault current limiting operation of this SFCL was obtained.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기설비전문위원
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• pp.35-36
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• 2007

We investigated the characteristics of three phase flux-lock type SFCL. Three phase flux-lock type consists of three reactor wound on an iron core in each single phase and the secondary coil is connected to the superconducting elements in series. the superconducting elements with serial connection were quenched simultangously in the single line-to-ground fault.

• Transactions on Electrical and Electronic Materials
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• 제6권5호
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• pp.193-197
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• 2005

We investigated fault current limiting characteristics of the flux-lock type superconducting fault current limiter (SFCL), which consisted of a primary winding and several secondary windings connected in series between $high-T_C$ superconducting (HTSC) thin films. Each YBCO thin film has a 2 mm wide and 42 cm long meander line with 14 stripes of different length. The power imbalance due to the slight difference of Ie between YBCO current limiting elements causes the significant power burden on YBCO element with lower $I_C$. We confirmed from our experiments that the mutual coupling between the primary winding and secondary windings of the flux-lock type SFCL reduced the power imbalance between YBCO current limiting elements compared with the resistive type SFCL connected in series.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2004년도 High Temperature Superconductivity Vol.XIV
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• pp.58-58
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• 2004

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.39-40
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• 2007

The analysis of fault current limiting characteristics according to variation of fault current level in the integrated three-phase flux-lock type superconducting fault current limiter (SFCL), which consisted of three-phase flux-lock reactor wound on an iron core with the same turn's ratio between coil 1 and coil 2 for each single phase, was performed. To analyze the current limiting characteristics of this integrated three-phase flux-lock type SFCL, the short circuit experiments was carried out the various three-phase faults such as the single line-to-ground fault, the double line-to-ground fault, the triple line-to-ground fault. From the experimental results, the fault current limiting characteristic was improved according to increase of fault current level.

• 한국전기전자재료학회논문지
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• 제25권12호
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• pp.1000-1003
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• 2012

The superconducting fault current limiter (SFCL) can quickly limit the fault current shortly after the short circuit occurs and recover the superconducting state after the fault removes and plays a role in compensating the voltage sag of the sound feeder adjacent to the fault feeder as well as the fault current limiting operation of the fault feeder. Especially, the flux-lock type SFCL with an isolated transformer, which consists of two parallel connected coils on an iron core and the isolated transformer connected in series with one of two coils, has different voltage sag compensating and current limiting characteristics due to the winding direction and the inductance ratio of two coils. The current limiting and the voltage sag compensating characteristics of a SFCL using a transformer winding were analyzed. Through the analysis on the short-circuit tests results considering the winding direction of two coils, the SFCL designed with the additive polarity winding has shown the higher limited fault current than the SFCL designed with the subtractive polarity winding. It could be confirmed that the higher fault current limitation of the SFCL could be contributed to the higher load voltage sag compensation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.200-202
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• 2006

We investigated the operating characteristics of a flux-lock type superconducting fault current limiters according to the number of the serial connection each the superconducting element at the additive polarity winding of a transformer. This SFCL consists of two coils wound in parallel on the same iron core, and the secondary coil is connected to the elements in series. Operating characteristics can be controlled by adjusting the inductances and the winding directions of the coils. It turns ratio between the primary and the secondary coils is 63:21. The analysis of voltage, current, and resistance in serial connection each element was performed to increase the applied voltage of flux-lock type SFCL. When the applied voltage was 200/$\sqrt{3}[V_{rms}]$ with three elements connected in seres, the peak value of the line current increased up to 26,24[A]. On the other hands, resistive SFCL increased up to 36.35[A], under the same conditions. This enabled the flux-lock type SFCL to be easy to increase the capacity of power system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전기설비전문위원
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• pp.93-96
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• 2004

In this paper, we analyzed the current limiting characteristics according to increase of source voltage in the flux-lock type high-Tc superconducting fault current limiter (SFCL). The flux-lock type SFCL consisted of two coils, which were wound in parallel each other through an iron core, and high-Tc superconducting (HTSC) element connected with coil 2 in series. The flux-lock type SFCL has the characteristics better in comparison with the resistive type SFCL because the fault current in the flux-lock type SFCL can be divided into two coils by the inductance ratio of coil 1 and coil 2. The fault current limiting operation of the flux-lock type SFCL can be different due to winding direction of the two coils. The winding method where the decrease of linkage flux between two coils in the accident happens is called the subtractive polarity winding and the winding method in case of the increase of linkage flux is called the additive polarity winding. The fault current limiting experiments according to the source voltage were performed for these two winding methods. Through the comparison and the analysis of the experimental data, we confirmed that the quench time was shorter, irrespective of the winding direction as the source voltage increased and that the fault current and the HTSC's resistance increased as the amplitude of the source voltage increased. The additive polarity winding made the fast quench time and the lower resistance of HTSC element in comparison with the subtractive polarity winding. The fault current of the subtractive polarity winding was larger than that of the additive polarity winding. In conclusion, we found that the additive polarity winding reduced the burden of SFCL because the quench time was shorter and the fault current was smaller than those of the subtractive polarity winding.

• 조명전기설비학회논문지
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• 제21권8호
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• pp.107-112
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• 2007

자속구속형 초전도 한류기는 1차 권선과 초전도 소자가 직렬로 연결된 2차 권선을 갖는 변압기로 구성되어 있다. 이 초전도 한류기는 결선방향에 따라 감.가극 결선으로 나누어진다. 1차 권선과 2차 권선의 인덕턴스 비에 따라 자속구속형 초전도 한류기는 사고전류의 제한특성을 제어할 수 있다. 본 논문에서는 인가전압에 따른 자속구속형 초전도 한류기의 전압 전류 특성을 분석하였다. 감 가극 결선된 자속구속형 초전도 한류기의 인가전압을 증가시켰을 때, 초기에 제한되는 전류 및 초전도 소자의 ??치 시간은 증가하였다. 초전도 소자의 회복시간은 인가전압이 증가함에 따라 증가하였다. 그러므로 자속구속형 초전도 한류기의 회복특성은 초전도 소자의 소비전력이 증가하기 때문에 초전도 소자에서 소비되는 에너지에 크게 의존한다는 것을 확인할 수 있었다.