• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
• /
• 2003.10a
• /
• pp.201-204
• /
• 2003

This paper presents the analysis of current limiting performance of superconducting fault current limiter(SCFCL) for real substation. The resistive and inductive type SCFCLs are investigated for 154㎸ substation. The current limiting performance of SCFCL is evaluated with respect to the time constant of SCFCL and impedance of SCFCL.

• Progress in Superconductivity
• /
• v.7 no.2
• /
• pp.174-178
• /
• 2006

For the practical application on SCFCL, Bi2212 tubes were fabricated by Centrifugal Forming Process (CFP) in terms of many different processing parameters. Typical sizes of tubes were 60, 150 mm in length and 2.5, 3.5, 4.8 mm in thickness. Initially powder was melted by induction heating. The optimum range of melting temperatures and preheating temperature were $1100^{\circ}C$ and $500^{\circ}C$ for 30min respectively. The nominal mold rotating speed was around 1000 RPM. A tube was annealed at $840^{\circ}C$ for 80 hours in oxygen atmosphere. The tube of 50mm x 70mm x 2.5mm, rotated with 1000 RPM showed $I_c=890\;A\;and\;T_c=80$. It was found that the tube processed with faster rate of mold rotation speed, thinner tube thickness and shorter tube length shows better electric characteristics as compared with the tube normally processed. In order to study the uniformity heat and fluid flow analysis tool was adopted along tube.

• Progress in Superconductivity
• /
• v.8 no.1
• /
• pp.104-107
• /
• 2006

For the practical application on SCFCL(Superconducting fault current limiters), Bi-2212 tubes were fabricated by Centrifugal Forming Process(CFP). The tubes were annealed at 830, 840, $850^{\circ}C$, respectively for 80 hours in oxygen atmosphere. The tubes heat treated at $840^{\circ}C$ demonstrated better electric characteristics than the tubes heat treated at 830 and $850^{\circ}C$. The typical value measured at 77 K in the self field was around 556 A. In terms of cooling effect on superconducting properties, it was found the electrical properties were quite dependent on the mold design and shapes. In order to check uniformity along the tube, EFDLab fur heat and fluid analysis of NIKA was adopted. It was found out that the simulation data was quite well matched with experimental results.

• 한국초전도학회:학술대회논문집
• /
• v.15
• /
• pp.92-92
• /
• 2005

• Proceedings of the KIEE Conference
• /
• 2007.11b
• /
• pp.145-147
• /
• 2007

현재의 전력계통은 날로 커지고 복잡해지고 있으며 이에 따라 계통의 사고발생 시 고장전류도 크게 증가하고 있다. 따라서 된 논문에서는 사고 시 큰 고장 전류를 신속하게 제거하기 위한 방법으로 한류기를 적용하고 그에 따른 계통에서의 영향을 평가하였다. 또한 계통에서 한류기의 영향을 평가하기 위해서 EMTP-RV(Electro Magnetic Transients Program - Restructured Version)론 이용하여 한류기가 투입된 22.9kV급 배전계통에서 1선 지락고장이 발생하였을 경우, 상전도 및 초전도 전류기의 특성에 따른 배전계통의 영향을 모의시험 하였으며 그 결과를 분석하였다.

• Proceedings of the KIEE Conference
• /
• 2007.11b
• /
• pp.156-158
• /
• 2007

전력계통의 단락 용량의 증가는 고장 발생시 계통의 안정성을 저해하고 심각한 전압 강하를 유발시킨다. 계통운영을 안정적으로 도모하기 위해서는 고장 전류의 억제가 무엇보다 중요하며 초전도 한류기의 설치의 필요성에 관한 연구가 활발히 진행되고 있다. 초전도 한류기를 계통에 적용하기 위해서는 우선 투입 시 계통에 미치는 영향의 검토가 우선되어야한다. 본 논문에서는 EMTP-RV 를 사용하여 배전 계통 및 초전도 한류기(SCFCL)를 모델링하고, 초전도 한류기 투입 위치에 따라서 계통의 영향을 모의 하고 분석 하였다.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.48 no.3
• /
• pp.173-178
• /
• 1999

In this paper, the characteristics of the shielded inductive superconducting fault current limiter(FCL) were simulated and analyzed. After determining parameters fo design for superconducting tube, iron core and primary coil, simple power system composed of shielded inductive FCL was simulated by the numerical analysis. The currents flowing under the fault condition could be limited below 50 A successfully. It was suggested that as the important factors of operational characteristics, the turns of primary coil and size of iron core play a major role for whether the shielded inductive SCFCL operated as inductive type or resistive type FCL.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.07a
• /
• pp.276-277
• /
• 2005

본 연구에서는 MCP법을 이용하여 Bi2212 초전도 튜브를 제작하고 공정 변수에 따른 초전도 튜브의 전기적 특성을 평가하였다. 초전도 분말은 $1100^{\circ}C$에서 용융하여 $300\sim500^{\circ}C$로 예열된 몰드 내에 주입하였으며 몰드는 1000 RPM으로 회전시켰다 제작된 초전도 튜브는 $840^{\circ}C$ 의 $O_2$ 분위기에서 72시간 열처리 하였다. SEM과 XRD 분석결과 튜브는 약 $40{\mu}m$의 크기를 갖는 Bi2212 초전도 상이 일정한 방향성을 갖으며 XRD 분석 결과 튜브 바깥부문에 Bi2201상이 존재하였다. 전기적 특성은 몰드 회전 속도가 증가할수록, 튜브의 두께가 증가할수록, 길이가 감소할수록 높은 $I_c$ 값을 나타내었으며, 이때 50 mm$\times$70 mm$\times$2.5 mm, 1000 RPM의 튜브에서 전기적 특성은 $I_c$=890 A, $T_c$= 80 K의 값을 나타내었다.