• 조명전기설비학회논문지
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• 제28권7호
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• pp.62-68
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• 2014

We proposed a series connection-type superconducting fault current limiter(SFCL) using E-I core that can prevent the internal magnetic flux generation of cores during normal operation, and prevent the saturation of cores due to a sudden magnetic flux generation at the initial stage of fault occurrence while limiting the peak current. Through a short-circuit simulation experiment, we analyzed the operating status of the two superconducting elements and limiting characteristics according to the size of the fault current peak before and after the failure. Further, the double peak current limiting characteristics according to the winding directions as well as the current and the voltage of each coil were compared and analyzed.

• 전기학회논문지
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• 제58권11호
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• pp.2122-2127
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• 2009

This study presents the failure rate and repair rate of Superconducting Fault Current Limiter(SFCL) and adjacent distribution equipments. When the fault current penetrated SFCL, the supply of electric power to the customers can be partly continued. It is expected that SFCL makes to improve the reliability index of customers. Contrary to the expectations, the series connection between SFCL and distribution system could deteriorate the reliability index. To evaluate the reliability index in the distribution system including SFCL, the failure rate and repair rate of SFCL are required as well as that of distribution equipments. Also, the insertion of SFCL makes to change the failure rate and repair rate of adjacent equipments. This study proposes a method to calculate the failure rate and repair rate of a component combining SFCL and adjacent equipments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.24-26
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• 1995

In this paper, we investigated transient fault currents in a magnetic coupling High-Tc superconducting current limiter(HCL). It has an important effect on the reliability and stability of the power system. In order to analyze transient fault characteristics of HCL, we fabricated a magnetic coupling HCL and tested it in different fault conditions. An important parameter of design and manufacture which makes HCL inherently reliable is reduction of inrush fault currents. Without inrush fault currents, the currents flowing under such conditions can be limited to a desired-value within one cycle. Inrush fault current depends on saturation, normal spot propagation velocity, turns ratio and the fault angle.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.131-133
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• 1995

Inductive high-Tc superconducting fault current limiter using YBCO superconducting ring in the secondary part has many advantages in power networks. It is based on the superconducting to normal transition and this paper describes its operational characteristics and experimental results, especially focused on the harmonic component analysis and recovery time. We fabricated and tested it under various conditions for the analysis of transient fault characteristics. And for the analysis of harmonics we used FFT methods. The superconducting ring was quenched in 240Arms and fault current was effectively limited to the lower current level. In addition, it was fast recovered when the fault condition was removed and after fault the system had odd harmonics.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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• pp.240-242
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• 2004

Maximum short circuit current of modern power system is becoming so large that the current should transmission capability. Although there are various kinds of method to solve this, approached from super conductivity Fault Current Limiter application viewpoint among them. High Temperature Superconductor-Fault Current Limiter (HTS-FCL) development is progressing according to HTS technology development, and system application is tried. For actual system application of such super conductivity FCL, an more efficient method was developed to find suitable FCL application locations using sensitivity factor comparing previous paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.427-429
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• 2004

As the load density of KEOCO system is higher, the fault current can be much higher than SCC(Short Circuit Capacity) of circuit breaker. Even though there are several alternatives to reduce fault current, as the superconductivity technology has been developed, the HTS-FCL (High Temperature Superconductivity Fault Current Limiter) can be one of the attractive alternatives to solve the fault current problem. This study presents the application of HTS-FCL in real customer system.

• 한국초전도ㆍ저온공학회논문지
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• 제10권3호
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• pp.9-13
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• 2008

It is very important to study the protective relaying system from the viewpoint of technical analysis to apply superconducting power devices to real power systems. In this paper, we developed Superconducting Fault Current Limiter (SFCL) analysis model using Real Time Digital Simulator(RTDS) for protective relay tests in power system with SFCLs. The RTDS model has the operation mechanism of a real SFCL system.

• 한국초전도ㆍ저온공학회논문지
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• 제12권3호
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• pp.39-43
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• 2010

In Korea, 22.9kV hybrid SFCL (Superconducting Fault Current Limiter) has been developed and carried out long-term field tests in Gochagn power test center of KEPCO through DAPAS program. The SFCL will be installed at a distribution line of Icheon substation in Korea. For the successful application, we have to design the specifications considering real power system operation. This paper proposes a concept of the operating current based rms value for the protection coordination with protective delays and studies a proper range of the current in Korean distribution power system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.1288-1289
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• 2011

세계가 점차적으로 "전화(電化)"됨에 따라 전기 에너지의 효과적인 분배와 사용이 급격히 중요하게 되었다. 일반 도체를 통한 전류의 흐름은 도체의 저항에 의해 줄열을 발생시켜 전기 에너지의 손실을 일으키고 결국은 에너지와 경제적 자원의 낭비를 초래하게 된다. 초전도체의 저항은 직류 전류에서는 0, 교류 전류에서는 거의 0이기 때문에 초전도체를 이용하면 전력 소자 및 기기의 부피와 무게를 현저히 줄일 수 있는 반면에 모든 전기 시스템의 효율을 향상시킬 수 있고, 에너지 사용의 절감에 따라 환경 문제에 도움을 줄 수 있다. 사고 전류 제한기의 설계에 있어서, 권선형태에 따른 솔레노이드 마그네트와 팬케이크 마그네트를 설계, 제작하여 자장 특성 및 한류 특성을 비교 하였다. 2세대 고온 초전도 선재로 불리는 YBCO 박막형 초전도 선재를 이용하여 동작 전류 증대를 위한 다병렬 솔레노이드 마그네트와 다병렬 팬케이크 마그네트를 제작하였다. 이를 이용하여 440 V/ 630 A급 초전도 사고 전류 제한기와 2 kA 급 대전류 통전 사고 전류 제한 모듈을 설계, 제작하여 단락 특성 시험을 수행하였다. 한편, 자장 응용 기기에 적용 가능한 더블 팬케이크 마그네트를 제 2 세대 초전도선재를 이용하여 설계, 시작하였다. 2세대 선재는 1세대 선재에 비하여 20 T 이상의 외부 자장에 대한 특성이 우수하여 고자장 마그네트 시스템에 더욱 적합하다. 이에 초전도 마그네트 보호를 위한 상전도 영역 전파 실험을 수행하여 CC 선재의 안정도를 측정하였다. 또한 영구전류모드 운전과 플럭스 펌프를 통한 전류 충전에 대한 연구도 병행하였다.

• 조명전기설비학회논문지
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• 제26권11호
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• pp.75-80
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• 2012

In this paper, the operational characteristics due to the introduction of the superconducting fault current limiter(SFCL) with a peak current limiting function were analyzed in the power distribution system. The parallel structure of the superconducting element can operate the peak current limiting function depending on the transient amplitude of fault current. We studied the operating characteristics of the introduction of the SFCL with a peak current limiting function in the power distribution system. Furthermore, we were analyzed between the SFCL with a peak current limiting function and the protection devices in the power distribution system, through the short circuit experiments.