• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
• /
• pp.73-77
• /
• 1990

In this paper we describe the solid-state ac-circuit breaker which has the characteristic of both a half cycle circuit breaker and a current limiting circuit breaker. This circuit breaker has a current limiting resistor in order to surprises the fault current to a certain level and discharge the energe included in circuit inductor. We explain the effect of circuit parameter on transient phenomena of switch device by using EMTP and finally design the control circuit consisted synchronous closing circuit, over- current detecting circuit and sensing circuit of rate of rise of fault current.

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

• Progress in Superconductivity
• /
• 제1권1호
• /
• pp.73-80
• /
• 1999

We investigated the current limiting characteristics of resistive and inductive SFCLs with 100 $\Omega$ of impedance for line-to-ground faults in the 154 kV transmission system. The fault simulation at the phase angles $0^{\circ}$, $^45{\circ}$, and $90^{\circ}$ showed that the resistive SFCL limits the fault current less than 17 kA without any DC component after one half cycle from the instant of the fault. On the other hand, the inductive SFCL suppresses the current below 14 kA, but with 5 kA of DC component which decreases to zero in 5 cycles. We concluded that the inductive SFCL has higher performance in current limiting effect, but the resistive SFCL was better from the viewpoint of less DC components.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 유기절연재료 전자세라믹 방전플라즈마 연구회
• /
• pp.161-163
• /
• 2001

We present the basic properties of a superconducting current limiting fuse (SCLF) based on YBCO/Au films. The SCLFs consists of YBCO stripes covered with Au layers for current shunt. Under the source voltage of 100 $V_{rms}$, the longer the duration time of fault current was, the shorter its discharge time was. The duration time of fault current and its discharge time were reduced by increased voltages in the range of 200 - 300 $V_{rms}$. We thought that this was because the quench propagation was limited by local melting generated with higher voltage.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
• /
• pp.255-258
• /
• 1999

We investigated the current limiting characteristics of resistive and inductive SFCLs with 100 $\Omega$ of quench impedance for a single line-to-ground fault. which accounts for about 70% of the total power line faults, in the 154 kV transmission system. The fault simulation at the phase angles 0$^{\circ}$, 45$^{\circ}$, and 90$^{\circ}$ showed that the resistive SFCL limited the fault current less than 15 kA without any DC component after one half cycle from the instant of the fault. On the other hand, the inductive SFCL suppressed the current below 12 KA, but with 3 kA of DC component which decreased to zero in 5 cycles. We concluded that the inductive SFCL had higher performance in current limiting but the resistive SFCL was better from the view point of DC components.

• 한국초전도저온공학회:학술대회논문집
• /
• 한국초전도저온공학회 2003년도 추계학술대회 논문집
• /
• pp.288-290
• /
• 2003

The transformer is expected to be an essential component of resistive type superconducting fault current limiter (SFCL) for both the increase of voltage ratings in SFCL and the simultaneous quench due to different critical current between HTSC elements. However, for the design to prevent the saturation of iron core and the effective fault current limitation, the analysis for operation of SFCL with consideration for the magnetization characteristics are required. In this paper, the fault current limiting characteristics related with the magnetization ones were investigated through the variation of the ratio of the number of turns in the 1st and the 2nd windings. The proper design condition with variation of the number of turns to make the effective fault current limiting operation could be determined.

• 조명전기설비학회논문지
• /
• 제23권2호
• /
• pp.77-81
• /
• 2009

병렬연결된 두 코일을 가진 자속구속형 초전도 전류제한기의 사고발생시 철심의 포화를 억제하기 위한 방안으로 공극을 도입하였다. 하지만, 공극의 도입으로 인해 자화전류가 증가하게 되어 자속구속형 초전도 전류제한기의 임피던스 감소를 초래하게 된다. 본 논문에서는 공극유무에 따른 병렬연결된 두 코일을 가진 자속구속형 초전도 전류제한기의 전류제한 특성을 등가회로와 실험결과에 대한 비교분석을 통해 공극도입의 장.단점을 확인하였다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 추계학술대회 논문집
• /
• pp.213-213
• /
• 2009

In this paper, we investigated the current limiting characteristics due to the application location of the superconducting fault current limiter (SFCL) such as the feeder, the bus, the secondary side of transformer in a power distribution system. In addition, the quench and the recovery characteristics of the SFCL installed in each location of the power distribution system were compared each other. Through the analysis, in case that the SFCL was applied into the feeder line, its current limiting and voltage-drop compensating characteristics were confirmed to be the more effective. On the other hand, the power burden of the SFCL was increased higher compared to the SFCL'S other application location.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 하계학술대회 논문집 B
• /
• pp.760-761
• /
• 2001

We have studied quench characteristics for current limiting elements of YBCO films in applied fields of 0 - 130 mT. The films were deposited on sapphire substrates and covered by gold top layer. The current limiting element consists of 2 mm wide YBCO stripes connected in series. The electric field - current density (E-J) measurements showed that the presence of applied magnetic fields induces uniform quench distribution for the stripes, otherwise non-uniform quenches were observed. We suggest that suppressing the critical current by increased fields due to fault current effectively forced the stripes of higher Jc(0) to quench, resulting in equalizing quench times.

• 한국초전도학회:학술대회논문집
• /
• 한국초전도학회 2006년도 High Temperature Superconductivity Vol.XVI
• /
• pp.80-80
• /
• 2006