• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.166-168
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• 2002

This paper presents a new numerical algorithm suitable for defining recloser reclaims time and blocking automatic reclosing during permanent faults on overhead lines. It is based on terminal voltage input data processing. The decision if it is safe or not to reclose is determined from the voltage signal of faulted and tripped line phase using Total Harmonic Distortion factor calculated by Discrete Fourier Transform. The algorithm was successfully tested using signals recorded on the real power system. The tests demonstrate the ability of presented algorithm to determine the secondary arc extinction time and to block unsuccessful automatic reclosing of HV lines with permanent fault.

• 전기학회논문지
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• 제59권8호
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• pp.1347-1352
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• 2010

This paper presents a new adaptive single-phase auto reclosure (SPAR) algorithm to discriminate between a permanent fault and a transient fault and to minimize a protection dead time. The algorithm precisely detects the extinction of the secondary arc, based on THD's profiles on the faulted phase voltage waveform. The EMTP/ATPDraw program was used to simulate the single phase grounding fault for evaluating the proposed algorithm. And the simulation results show that the proposed algorithm is performing well.

• 한국전자통신학회논문지
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• 제17권3호
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• pp.417-422
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• 2022

선로를 따라 흐르는 전력흐름은 장기간에 걸쳐서 차단되지 않는 연속성을 갖는 것이 바람직하다. 배전선로에서 재폐로기의 최적 기준은 전력계통의 신뢰성을 개선하는 것으로 알려져 있으며, 배전계통에서 보호기능은 이러한 재폐로기의 수량과 위치가 매우 중요하다. 본 연구에서는 배전망 사고 동안 발생되는 손실을 줄이기 위하여 재폐로 동작 횟수를 포함한 보호기법의 사용 효과를 검토한다. 본 연구의 최종 목적은 표준 배전망에 대한 PSCAD/EMTDC의 모의데이터를 기반으로 사고전류 조건과 재폐로 동작 횟수를 결정하는 것이다. 피더의 보호기능인 재폐로기에서 동작횟수 결정은 배전망의 최적 운영과 신뢰성 확보에 도움이 된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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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.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.795-803
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• 2015

Autoreclosure provides a means of improving power transmitting ability and system stability. Conventional reclosure adopts the fixed dead time interval strategy, where the reclosure is activated after a time delay to restore the system to normal as quickly as possible without regard to the system conditions. However, these simple techniques cannot provide optimal operating performance. This paper presents an adaptive autoreclosure algorithm including variable dead time, optimal reclosure, phase-by-phase reclosure and emergency extended equal-area criterion (EEEAC) algorithm in order to improve system stability. The reclosure algorithm performs the operations that are attuned to the power system conditions. The proposed adaptive reclosure algorithm is verified and tested using ATP/EMTP MODELS, and the simulation results show that the system oscillations are reduced and the transient stability is enhanced by employing the proposed adaptive reclosure algorithm.

• 대한전기학회논문지:전력기술부문A
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• 제52권12호
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• pp.698-704
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• 2003

Autoreclosure provides a mean of improving power transmitting ability and system stability. The conventional reclosure adopts the fixed dead time interval strategy, that is, the reclosure is activated after a time delay to restore the system to normal as quickly as possible without regard to the system conditions, however, these simple techniques cannot give the optimal operating performance. For this reason, various adaptive reclosure algorithms have been proposed recently, This paper presents an adaptive autoreclosure algorithm including the variable dead time, optimal reclosure, sequential reclosure and emergency extended equal-area criterion (EEAC) algorithm in order to improve the system stability. The reclosure algorithm performs out the operations that are attuned to the power system conditions. The proposed adaptive reclosure algorithm is verified and tested by using EMTP MODELS, and the simulation results show that the system oscillations are reduced and the transient stability is enhanced by employing the proposed adaptive reclosure algorithm.

• Journal of Electrical Engineering and Technology
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• 제1권1호
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• pp.8-15
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• 2006

Since the power swing depends on the operating time of the relay, the swing's magnitude can be reduced by an autoreclosure relaying system with an optimal reclosing algorithm. This paper proposes a method for stability improvement using optimal reclosure relaying. An optimal reclosure algorithm is applied to identify both temporary and permanent faults, and to predict system stability by applying WAM and high speed communication technology. It provides optimal control by predicting and determining the degree of stability, considering the real time transient stability using EEEAC. For temporary faults, the algorithm determines the system's stability and either recloses optimally for stable systems, or inserts series capacitance before optimal reclosure for unstable systems. It also applies an optimal reclosure algorithm to minimize shock and damage to the power system when reclosure fails due to permanent faults.

• 한국전자통신학회논문지
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• 제18권5호
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• pp.817-826
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• 2023

본 논문에서는 스마트 그리드 배전 계통에서 선로상의 고장으로부터 계통을 보호하기 위한 인공 신경 회로망을 기반으로 하는 고장 판단 방법론을 제안하였다. 제안된 방법론에서는 먼저 전류 실효값 크기를 기반으로 일반 고장 여부를 판단하고 다음, 정상 전류로 판단되는 경우 인공 신경 회로망을 기반으로 하는 normal/HIF classifier를 이용하여 고 임피던스 지락 고장 여부를 판단하도록 설계하였다. 반복적인 DSP 모듈 기반 알고리즘 검증 시험들 중에서, 실효 값 크기가 최소 동작전류보다 작은 정상 전류 파형 시험인 경우에 normal/HIF classifier가 전류 파형을 정상상태로 인식하여 부 동작하였으며, 반면에, 저 임피던스 고장의 경우는 고장 상태로 인식하여 정해진 절차에 따라 재폐로 동작을 보임으로써 제안된 방법론의 유효성을 확인할 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.664-666
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• 2005

본 논문에서는 장거리 초고압 송전선로에서의 단상재폐로시에 발생가능한 과전압과 2차아크전류를 EMTP를 이용하여 예측계산 하였다. 예측계산결과로부터 과전압을 억제하고 재폐로 동작이 가능한 최적의 중성점 리액터와 400 kV 급 수평배열 1회선 선로를 단상으로 재폐로 하는데 필요한 재폐로 무전압시간을 구하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전력기술부문
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• pp.99-101
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• 2006

As the same concept with GIB, GIL(Gas Insulated Line) has been established and run for the first time in New Jersey, America, in 1972. At the beginning, the installation condition of GIL was complicated and the construction cost was excessive, so it was not economical, but the construction cost was substantially reduced with the use of insulation material which is the mixture of $SF_6$ and $N_2$ Gas in Germany, in 1990s. And also comparing to cable, GIL has lots of advantages, such as being capable of the high voltage transmission, being applied to reclosing and lowering the strength of electromagnetic force, Due to these advantages, GIL is recently accepted in many countries.