• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1999.11a
• /
• pp.85-88
• /
• 1999

We fabricated resistive superconducting fault current lmiters based on YBa$_2$Cu$_3$O$_{7}$ thin films and investigated their quench propagation characteristics. The YBa$_2$Cu$_3$O$_{7}$ film was coated with a gold layer and patterned into 1 mm wide meander lines by photolithography. The limiters were tested with simulated fault currents of various fault angles and amplitudes. The quench propagation characteristics were explained based on the heat transfer within the film as well as between the film and the surrounding liquid nitrogen. The quench completion time strongly depended on the potential fault current. It was 1 msec at the peak fault current of 76 A/peak/ and corresponding quench propagation speed was 43 m/sec (film cross section: 4 x 10$^{-6}$ $\textrm{cm}^2$).

• Proceedings of the KIEE Conference
• /
• 2001.10a
• /
• pp.68-70
• /
• 2001

고온 초전도체를 이용한 전력기기들은 변압기, 한류기 등의 정지기기의 형태와 회전기로서는 동기발전기, 벌크형 전동기, 동기전동기 등에 개발되고 있다. 이중 회전기에서 고온초전도를 이용한 유도전동기의 개발은 국내외적으로 미비한 실정이다. 본 논문에서는 고온초전도체를 이용한 농형 유도전동기의 제작 및 시험을 통하여 기본특성을 확인하였다.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.1
• /
• pp.36-42
• /
• 2010

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.3
• /
• pp.44-48
• /
• 2009

• 한국초전도학회:학술대회논문집
• /
• v.9
• /
• pp.348-351
• /
• 1999

We investigated current limiting properties for an SFCL of YBCO thin film coated with an Au layer. The YBCO film of 1 mm wide and 400 nm thick could carry the current 9.6 A$_{peak}$ without quench. The SFCL limited the fault current below 7.6 A$_{peak}$, which otherwise increases above 65 A$_{peak}$ and melted down at the potential fault current of about 100 A$_{peak}$ which is 10 times greater than the quench current. This means that the Au layer successfully protected the superconducting film by dispersing the heat generated at hot spots and electrically shunting the YBCO film.

• Journal of the Economic Geographical Society of Korea
• /
• v.16 no.2
• /
• pp.182-197
• /
• 2013

This paper deals with the relationship between cultural factor and economic factor in the spread of Hallyu(Korean Wave). To do so, the paper defines the traditional Hallyu items, drama and K-Pop, as 'cultural Hallyu' and other Popular industrial products such as electronics and mobile products as 'business Hallyu'. Based on this definition, the paper analyzes the relationship between the two Hallyu's in Thailand. The analysis has been conducted as follows. First, the paper describes the history of 'cultural Hallyu' and 'business Hallyu' in Thailand by reviewing their introduction and current situations in Thailand market. Secondly, using various aggregate data, the paper analyzes the causality of the two Hallyu's, focusing on the period of their Popularity and growth in Thailand. In addition to the macro-level analysis, the paper researched individual opinions of Thai people about the influence of Hallyu on the success of Korean companies, as well as about the influence of the Korean business companies on the success of Hallyu. This analysis has been conducted using the results of focus group discussion(FGD) of 17 Bangkok people. In both macro and individual level analyses, we found that the 'cultrual Hallyu' has influenced on the success of the 'business Hallyu' rather than vice versa. For further research, it is necessary to analyze the reciprocal influences and synergy effects between the 'cultural Hallyu' and 'business Hallyu'.

• 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.

• Proceedings of the KIEE Conference
• /
• 2005.07c
• /
• pp.2232-2234
• /
• 2005

배전 계통에서는 전동기의 시동 전류, 변압기의 여자돌입전류, 콘덴서의 고주파 과도 돌입전류 등의 과전류가 흐르므로, 회로 보호용 한류 퓨즈가 엘리먼트의 피로나 열화 등에 의해, 예기치 못한 용단이 발생한다. 이 경우 고장을 미연에 방지하기 위해, 한류 퓨즈의 신뢰성을 보다 향상시키기 위해서는 제품 특성의 균일성을 확보함으로서 그 사용 실태에 대응해서 적절히 교환하는 것이 필요하다.

• Superconductivity and Cryogenics
• /
• v.6 no.2
• /
• pp.16-20
• /
• 2004

전 세계적으로 대규모 정전사태가 발생하고, 국내 전력계통의 경우에도 전력수요가 폭발적으로 증가하여 단락, 지락, 낙뢰 등의 전력사고(고장) 발생 시 기존 차단기의 용량으로는 차단할 수 없는 대형 사고가 발생하고 있다. 이렇게 대규모의 정전 사태의 원인은 병렬 network이다. 우리나라 역시 전기공급을 병렬 network로 운전하고 있어 대규모 정전 사태에 직면할 가능성이 있다.(중략)

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.5
• /
• pp.705-712
• /
• 2003

Analysis for the thermal stress distribution in the laminated plates containing a hot-spot(local heating region) is performed. It is assumed that the local heating region induces only mechanical stress by the thermal expansion but effect of the thermal conduction is neglected. The region is regarded equivalent to a homogeneous inclusion expanding in a laminated medium. As an example, Au/YBCO/Al$_2$O$_3$laminate which is often employed for High Temperature Superconducting Fault Current Limiter(HTS FCL) has been analyzed. Effects of heat input, thickness of each layer and the got spot size upon the stress distribution in the hot-spot have been investigated. For a constant heat generation into the hot-spot, as the thickness of the Al$_2$O$_3$substrate increases, the stress in the YBCO layer is peculiarly oscillated, and the curvature of laminate has a maximum at a certain thickness of the Al$_2$O$_3$.