• 한국전기전자재료학회논문지
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• 제13권9호
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• pp.801-804
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• 2000

High-temperature superconductor of Bi-2212 system was fabricated by CFP(Centrifugal Forming Process). To make a uniform specimen slurry was prepared in the ratio of 7:3(powder : binder) and ball milled for 24 hours. Milled slurry was charged into a rotating mold with 450 rpm and dried at room temperature. Then the specimen was performed binder burn-out at 35$0^{\circ}C$ and heated for partial melting to 86$0^{\circ}C$. XRD analysis of most specimens were shown 2212 phase and observed a local plate shped microstructure with a well aligned c-axis direction from SEM images. Measured T$_{c}$(Critical temperature) was about 64 K.K.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전력기술부문
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• pp.250-252
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• 2002

Nowadays, one of the serious Problems in KEPCO system is the more higher fault current than the SCC(Short Circuit Capacity) of circuit breaker. There are many alternatives to reduce the increased fault current. As the superconductivity technology has been develops, the HTS-FCL(High Temperature Superconductor-Fault Current Limiter) can be a one of the attractive alternatives to solve the fault current problem. Under the this background, this paper presents distribution system EMTDC modeling and the application of EMTDC model for resistance type HTS-FCL in the developed distribution system model.

• 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 1999년도 추계학술대회 논문집 학회본부 A
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• pp.86-88
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• 1999

We investigated the current limiting characteristics of resistive and inductive SFCLs with $100{\Omega}$ of quench impedance for a line-to-line fault 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 13 kA, but with $2{\sim}3\;kA$ of DC component which decreased to zero in 6 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.

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

• Water Engineering Research
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• 제3권1호
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• pp.23-30
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• 2002

A numerical model for the solution of two-dimensional dam break problems using fractional step method is developed on unstructured grid. The model is based on second-order Weighted Averaged Flux(WAF) scheme with HLLC approximate Riemann solver. To control the nonphysical oscillations associated with second-order accuracy, TVD scheme with SUPERBEE limiter is used. The developed model is verified by comparing the computational solutions with analytic solutions in idealized test cases. Very good agreements have been achieved in the verifications.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.278-278
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• 2011

수소 중성입자빔을 이용한 silicon etching은 기존의 silicon etching 공정 가스(Fluorine이나 Chlorine 계열의 가스) 사용 시 배출되는 유해 가스로 인한 지구 온난화 방지 및 폐기물 처리에 추가적인 비용이 발생하지 않는 친환경 etching 공정이다. 본 연구에 사용된 수소 중성입자빔을 발생시키기 위한 플라즈마 소스는 낮은 압력에서 높은 플라즈마 밀도를 발생시킬 수 있는 ECR 플라즈마 소스를 사용하였으며 중성입자빔의 에너지를 조절할 수 있는 중성화판과 플라즈마로부터의 전하손상을 방지할 수 있어 charge free 공정을 가능하게 하는 Limiter로 구성되어 있다. 본 연구에서는 플라즈마 밀도, 공정 압력 그리고, 중성입자빔의 에너지를 조절하여 수소 중성입자빔을 이용한 poly-crystal silicon과 a-Si:H 간의 etch rate와 etching selectivity를 관찰하였다.

• 한국자동차공학회논문집
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• 제17권3호
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• pp.117-126
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• 2009

A Common-Rail Direct Injection(CRDI) system for high speed diesel engines was developed to meet reductions of noise and vibration, and emission regulations. In this study, CRDI system analysis model which includes fuel and mechanical sub-systems was developed using commercial software, AMESim in order to predict characteristics for various fuel injection components. Each component which constructs system was modeled and verified by sub-model of AMESim obtained characteristics curves of each components. The parameter sensitivity analysis such as throttle size, injection rate, plunger displacement, supply pressure of fuel injection for system design were carried out by the analysis.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 학술대회 논문집
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• pp.213-215
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• 2003

This paper deals with the characteristics of a prototype solenoid for basic design of DC reactor type superconducting fault current limiter (SFCL). The prototype high-Tc Super-conducting (HTS) solenoid was manufactured with 4 stacked Bi-2223 tape. The critical currents were measured with respect to the number of stacks. In order to test the safety of HTS solenoid in quenched state, the transport tests of AC over-current were performed. These experimental results could be applied to the basic design of HTS DC reactor for SFCL effectively.

• 한국초전도ㆍ저온공학회논문지
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• 제7권2호
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• pp.16-20
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• 2005

As power systems grow more complex and power demands increase, the fault current tends to gradually increase. In the near future, the fault current will exceed a circuit breaker rating for some substations, which is an especially important issue in the Seoul metropolitan area because of its highly meshed configuration. Currently, the Korean power system is regulated by changing the 154kV system configuration from a loop connection to a radial system, by splitting the bus where load balance can be achieved, and by upgrading the circuit breaker rating. A development project applying 154kV Superconducting Fault Current Limiter (SFCL) to 154kV transmission systems is proceeding with implementation slated for after 2010. In this paper, SFCL is applied to reduce the fault current in power systems according to two different application schemes and their technical impacts are evaluated. The results indicate that both application schemes can regulate the fault current under the rating of circuit breaker, however, applying SFCL to the bus-tie location is much more appropriate from an economic view point.