• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 제4회 영호남학술대회 논문집
• /
• pp.105-108
• /
• 2002

In this paper, we investigated the fault current limiting characteristic of flux-lock type High-Tc superconducting fault current limiter(HTSC-FCL), which is comprised of a flux-lock reactor and an external magnetic field coil covering the HTSC element In this HTSC-FCL, the initial limiting current level can be controlled by adjusting the inductance of the each coil. Furthermore, the fault current limiting characteristics of HTSC-FCL can be improved by applying 'the external magnetic field into the HTSC element We performed the computer simulation by numerical analysis about the flux-lock type HTSC-FCL and compared the results of experiment with simulation ones. We can obtain the same results from both the computer simulation and the experiment except for the time immediately after fault occurs.

• 한국전기전자재료학회논문지
• /
• 제29권10호
• /
• pp.630-634
• /
• 2016

In this paper, we analyzed the power consumption and the accumulated energy in HTSC (high-TC superconducting elements) according to the resistance of HTSC element and the winding current of transformer type SFCL (superconducting fault current limiter) using double quench. For the analysis, two different inductances of the one secondary winding among two secondary windings comprising the transformer type SFCL were selected and the short-circuit tests were carried out. The consumed power and the accumulated energy in HTSC element connected into the secondary winding with larger inductance were analyzed to be larger compared to the one connected into the secondary winding with lower inductance.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
• /
• pp.68-70
• /
• 2007

The operational characteristics of superconducting fault current limiter (SFCL) using magnetic coupling of coils were investigated. This SFCL consists of a high-Tc superconducting (HTSC) element and two coils with series or parallel connection on the same iron. This SFCL has the merit that the operational current of SFCL can be increased higher than the critical current of the superconducting element by adjusting the inductance ratio between two coils. To confirm its operation, the circuit for the fault simulation was constructed. From the measured voltage and current of the SFCL, it was confirmed that the resistance of HTSC element comprising this SFCL increased more than that of HTSC element's independent operation.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
• /
• pp.681-682
• /
• 2006

This paper deals with the preliminary study on the HTSC levitation magnet for MAGLEV operating in persistent current mode (PCM). The high temperature superconducting (HTSC) levitation magnet consists of two single-pancake type coils wound with Bi-2223 wire and a persistent current switch (PCS). The levitation magnet was designed by using 3-D finite element analysis. The suspension system for high-speed electrodynamic suspension (EDS) maglev should operated in persistent current mode. It is important to develop a technology to minimize the joint resistance of splice between two HTSC wires. The PCS was observed with respect to various magnitude of charging current. Based on these results, the levitation system using HTSC wire will be further studied.

• 한국산학기술학회논문지
• /
• 제17권5호
• /
• pp.717-722
• /
• 2016

본 논문은 고장발생 초기 고장전류의 크기에 따라 피크전류제한 기능을 갖도록 하나의 철심에 기존 1차 코일과 2차 코일이 병렬로 연결된 초전도 소자 1과 추가적인 철심을 사용하여 3차 권선에 초전도 소자 2가 연결된 자기결합형 초전도한류기를 제안하였다. 이중 철심을 이용하여 코일 1과 코일 2간 병렬로 연결한 자기결합형 초전도한류기가 고장발생시 피크전류를 초전도 소자 1만이 분담하는 것을 확인할 수 있었다. 그 이유는 초기 사고전류의 순간적인 요소가 커서 초전도 소자 1이 ?치되어 작동하였으나, 코일 3에 흐르는 전류가 임계전류를 초과하지 않았고, 이로 인해 초전도 소자 2가 ?치되어 작동하지 않았기 때문이다. 사고 시 피크전류를 순차적인 초전도 소자로 제한하기 위해서는 코일 1이 낮은 자기인덕턴스 값을 갖고 있으면서도 코일 2보다 코일 3이 보다 높은 자기인덕턴스 값을 갖도록 설계해야 할 것이다. 또한, 고장 발생 초기 사고전류의 크기를 결정하는 고장조건 중의 하나인 1차 코일과 2차 코일간의 권선비가 0.25일 때 두 SFCL의 전류제한 및 회복특성에 대한 검증을 선로단락실험을 통해 분석되었다. 이 단락실험의 분석결과, 가극결선인 경우가 감극결선한 경우보다도 전류제한 및 회복특성이 더욱 우수함을 확인할 수 있었다.

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

• 한국전기전자재료학회논문지
• /
• 제30권2호
• /
• pp.101-105
• /
• 2017

In this paper, the magnetization characteristics and the stored energy of magnetically coupled superconducting fault current limiter (SFCL)s using single and double high-Tc superconducting (HTSC) elements were compared. To analyze the magnetization characteristics and the stored energy, the magnetizing current and the flux linkage, which were derived from the electrical equivalent circuit of the SFCL using single and double HTSC elements, were calculated from the voltages and the current measured in the short-circuit tests. Through the comparative analysis on the magnetization characteristics and the stored energy for SFCL using sing and double HTSC elements, the magnetically coupled SFCL using double HTSC elements was shown to be more effective than the SFCL using single HTSC element from the point of view of the magnetic saturation.

• 한국전기전자재료학회논문지
• /
• 제36권6호
• /
• pp.614-619
• /
• 2023

The fault current limiting characteristics of three-phase transformer type superconducting fault current limiter (SFCL), which consisted of three-phase primary and secondary windings wound on E-I iron core, one high-TC superconducting (HTSC) element connected with the secondary winding of one phase and another HTSC element connected in parallel with other two secondary windings of two phases, were analyzed. Unlike other three-phase transformer type SFCLs with three HTSC elements, three-phase transformer type SFCL using double quench has the merit to perform fault current limiting operation for three-phase ground faults with two HTSC elements. To verify its proper three-phase ground fault current limiting operation, three-phase ground faults such as single-line ground, double-line ground and triple-line ground faults were generated in three-phase simulated power system installed with three-phase transformer type SFCL using double quench. From analysis of its fault current limiting characteristics based on tested results, three-phase transformer type SFCL using double quench was shown to be effectively operated for all three-phase ground faults.

• 조명전기설비학회논문지
• /
• 제21권10호
• /
• pp.46-51
• /
• 2007

본 논문에서는 두 코일의 직 병렬결합을 이용한 초전도 사고전류제한기의 사고전류제한 특성을 분석하였다. 구조는 병렬 또는 직렬로 연결된 두 코일과 두 코일 중 하나와 직렬 또는 병렬로 연결되는 초전도 소자로 구성된다. 동작원리는 사고전에는 초전도 소자는 초전도 상태에 있어 병렬 또는 직렬로 연결된 두 코일에 의해 발생되는 자속은 서로 상쇄되어 두 코일에 유기되는 전압이 제로를 유지하게 되지만 사고가 발생할 경우 초전도 소자의 저항이 발생되어 두 코일에서 발생되는 자속은 더 이상 상쇄되지 않게 된다. 따라서 두 코일에 전압이 유기되고 이에 따라 사고전류를 제한하게 된다. 단락실험을 통해 두 코일의 직 병렬결합에 따른 사고전류제한 특성을 분석하였으며 분석을 동해 사고전류제한기의 동작전류를 증가시킬 수 있음을 확인하였다.

• 대한전기학회논문지:전력기술부문A
• /
• 제53권11호
• /
• pp.619-623
• /
• 2004

We proposed the bridge type superconducting fault current limiter(SFCL) using switching operation of high-Tc superconducting(HTSC) thin film. The proposed bridge type SFCL consists of HTSC thin film, a diode bridge and a dc reactor. The controller for the operation of an interrupter is required in the conventional bridge type SFCL to prevent the continuous increase of fault current after a fault happens. On the other hand, the proposed bridge type SFCL can limit the fault current without the interrupter and the controller for its operation by the resistance generated when the gradually increased fault current exceeds HTSC thin film's critical current. We calculated the time when the gradually increased fault current started to be limited by the resistance generated in HTSC thin film after a fault happened and confirmed that it could be dependent on the amplitude of source voltage. The experimental results well agreed with the calculated ones from simulation.