• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.726_727
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• 2009

본 논문에서는 최근 안전에 논란이 되어 2008년 안전기준이 제정된 자동복귀(복구, 재폐로) 누전차단기에 대한 표준화 동향을 정리하고 추후 제도적 안정과 대민안전을 위한 발전방향을 제시하였다.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.36-38
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• 2004

In many countries, including Korea, in order to transmit the more electric power, the higher transmission line voltage is inevitable. So, a rapid reclosing scheme is important for UHV transmission lines to ensure requirements for high reliability of main lines. But, because of the high voltage and long span of UHV lines, the secondary arc current flows across the fault point even after the interruption of the fault current. i.e. A critical aspect of reclosing operation is the extinction of the secondary arc since it must extinguish before successful reclosure can occur. In Korea transmission lines, it is scheduled to energize 765kV single transmission line(79km) between Sin-Ansung S/S and Sin-Gapyeong S/S at June 2006. Therefore this paper analyzes characteristics of the secondary arc extinction on 765kV single transmission line using EMTP. Simulation results shows that the average value of the secondary arc is $30A_{rms}$ and the auto-extinction time of it is longer at closer point to Sin-Gapyeong S/S.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.2
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• pp.70-75
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• 2006

Owing to the strike of lightning a breakage of insulator would happen. This breakage may give rise to many problems such as increment of reclosing failure, a drop for reliance and a hardship of maintenance and repair. To solve those problem, this study develop a protected equipment for insulator which is suitable to 22.9[kV] distribution line towers and is purposed to investigation for a Proper adaption, Protection efficiency of insulator and effect of adaption.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.2011-2013
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• 2000

Insulators of transmission line have been frequently damaged by lightning flashover. Arcing horns have been installed on string sets to protect insulators from the flashover. But reclosing number can be increased by the decrease of insulation strength and they are worrying it. Then this paper analyzes the installation effects of the arcing horn.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.906-908
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• 2000

This paper presents dynamic modeling and simulation of induction motors. Equivalent circuit parameters measured by do test, no-load test and locked-rotor test were used as the input data for computer simulation. Operating characteristics of an induction motor were predicted by Matlab/simulink when changing load torque, opening and reclosing of phase a of the stator and three-phase fault at machine terminals.

• Proceedings of the KAIS Fall Conference
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• 2006.11a
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• pp.172-175
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• 2006

Owing to the strike of lighting a breakage of insulator would happen. This breakage may give rise to many problems such as increment of reclosing failure, a drop for reliance and a hardship of maintenance and repair. To solve those problems, this study develop a protected equipment for insulator which is suitable to 22.9kV distribution line towers and is purposed to investigation for a proper adaption, protection efficiency of insulator and effect of adaption.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.655-656
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• 2007

전력 계통에 연계형 분산전원이 도입되므로 인하여 기존배전선로와 달리 양방향 전력조류가 발생, 이에따른 보호계전방식의 수정을 필요로 하므로, PSCAD-EMTDC 시뮬레이터를 통하여, 이때의 배전계통의 현상들을 모의하고, 이에 따른 대책을 제시하므로 하여 배전계통 신뢰도를 향상시키기 위한 연구를 진행하였습니다. 기존선로를 이용해 연계된 분산전원과, 전용선로를 통하여 연계된 분산전원을 모의하고, 부하 상태와 사고 형태에 따른 시뮬레이션을 진행 현상을 분석하여 새로운 운영방식을 제시하였다.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.518-519
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• 2015

전력효율을 높일 수 있는 DC 전송이 주요 관심사가 됨에 따라 전력품질에 대한 기술이 요구된다. DC 그리드의 전력품질을 위해서는 반도체 차단기는 필수요소이다. 따라서 본 연구에서는 신속한 차단이 가능하고 재투입과 재차단 기능을 갖는 반도체 차단기를 제안한다. 제안한 회로는 단락 사고를 모의하고 시뮬레이션과 실험을 통해 시스템의 동작 특성을 검증하였다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1942-1943
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• 2007

전력 계통에서는 순간적인 고장을 제거하고 양질의 전력공급을 지속시키기 위해 재폐로가 사용된다. 계통에서 고장검출 이후 차단기가 개방 되면, 전송 선로에 포획전하가 발생하여 높은 잔류 전압을 발생 시키고, 이러한 포획 전하는 선로의 재폐로시 과전압, 과전류를 발생시킨다. 재폐로시 포획 전하에 의한 과전압은 pre-insertion 저항을 삽입함으로서 경감시킬 수 있다. 본 논문에서는 이러한 포획 전하에 의한 영향을 EMTP를 통하여 분석하였다.

• Progress in Superconductivity
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• v.10 no.1
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• pp.60-67
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• 2008

We present domestic efforts for superconducting fault current limiter (SFCL) application in the Korea Electric Power Corporation (KEPCO) grid and pending points at issue. KEPCO's decision to upgrade the 154 kV/22.9 kV main transformer from 60 MVA to 100 MVA cast a problem of high fault current in the 22.9 kV distribution lines. The grid planners supported adopting an SFCL to control the fault current. This environment friendly to SFCL application must be highly dependent upon the successful development of SFCL having specifications that domestic utility required. The required conditions are (1) small size of not greater than twice of 22.9 kV gas insulated switch-gear (GIS), (2) sustainability of current limitation without the line breaking by circuit breakers (CB) for maximum 1.5 seconds. Also, optionally, recommended is (3) the reclosing capability. Conventional resistive SFCLs do not meet (1) $\sim$ (3) all together. A hybrid SFCL is an excellent solution to meet the conditions. The hybrid SFCL consists of HTS SFCL components for fault detection and line commutation, a fast switch (FS) to break the primary path, and a limiter. This characteristic structure not only enables excellent current limiting performances and the reclosing capability, but also allows drastic reduction of HTS volume and small size of the cryostat, resulting in economic feasibility and compactness of the equipment. External current limiter also enables long term limitation since it is far less sensitive to heat generation than HTS. Semi-active operation is another advantage of the hybrid structure. We will discuss more pending points at issues such as maintenance-free long term operation, small size to accommodate the in-house substation, passive and active control, back-up plans, diagnosis, and so on.