• 한국항공우주학회지
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• 제31권9호
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• pp.110-120
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• 2003

고공을 운항하는 항공기는 대기중의 자연현상에 의해 낙뢰에 노출되게 된다. 낙뢰 피해는 개발초기에는 목재 항공기의 절연파괴에 의한 손상과 화재등이 있었으며 알루미늄의 보급으로 전금속체 항공기가 개발되었지만 연료탱크의 화재 문제라든지 낙뢰 사고는 계속 발생하였다. 이에 NACA에서는 1938년 문제를 제기하고, 인공 낙뢰에 대한 연구를 시작하였다. 이어 FAA에서는 낙뢰보호에 대한 인증을 위해 감항기준을 제정하고 SAE에 낙뢰에 대한 항공기의 보호를 위한 시험대책 연구를 의뢰하여 낙뢰를 모사한 시험 전류, 전약 파형을 제시하여 항공기의 낙뢰보호, 인증에 활용하고 있다. 이 글에서는 낙뢰의 메커니즘 분석을 통한 항공기에 대한 낙뢰의 영향을 제시하고 특히 항공기 안전사고의 중요한 요인으로 대두되고 있는 항공기에 대한 낙뢰의 직접영향에 대한 사례를 분석하고 인증기준과 시험 전류 및 전압파형, 낙뢰 피격부위를 열거하여 개발항공기 및 비행체에 대한 인증에 활용되도록 하였다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제51권10호
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• pp.479-484
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• 2002

Recently it is reported that many a malfunction of ELB which is represented by non-operated type ELB for an impulse wave, is caused by lightning impulse and transient ground potential rise due to nearby lightning strokes. In order to examine the cause of malfunction, 5 samples were investigated experimentally in this study. As each ELB has a different leakage current detecting circuit and wiring method, various characteristics were measured. As a result, all of them brought about malfunctions under the lightning impulse voltage less than 7 kV and the surge current less than 3 kA. Also the different aspects were measured with a polarity of injected surge and a position of MOV to protect the inner circuit of ELB. The Position and effects of protecting devices were suggested as a remedy.

• 조명전기설비학회논문지
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• 제25권10호
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• pp.109-115
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• 2011

Apartments covered with a metal roof made from galvalume steel are prevailing due to their economic and technical advantages. The metal roof, however, has disadvantages in terms of the installation of air-termination system on it because of the slip thickness of the metal roof. In this paper, the impacts of the lightning current to a metal roof were verified experimentally with a short lightning impulse current (10/350[${\mu}s$]). Also, we developed various supporters of air-termination conductor for the metal roof and verified their excellent workability and economical strength through field application test.

• 조명전기설비학회논문지
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• 제28권5호
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• pp.98-105
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• 2014

Soil discharges near the ground rod play an important role to reduce the ground potential rise and the ground impedance and to help the fault current to spread into the earth. This paper presents the effects of soil discharges on the transient and conventional ground impedances when the lightning impulse voltage was applied to a ground rod with radial needles. The current-voltage (I-V)curves and transient ground impedance curves were calculated based on the measured current and potential traces. Soil discharge behaviors related to I-V curves and transient ground impedance curves were analyzed as a function of the magnitude of lightning impulse voltages. As a result, the soil discharges occurred near the ground electrode contribute to the reduction of conventional ground impedance and limits the ground potential rise effectively under lightning impulse voltages.

• 한국전기전자재료학회논문지
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• 제22권6호
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• pp.526-531
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• 2009

In this paper, the safety for passengers of composite car-body against lightning strikes was analyzed by the application of an impulse generator which can produce impulse current up to 50 kA with 8/$20{\mu}s$ waveform. Potential difference on inside surface of the car-body was measured as a safety parameter for the passengers against lightning strikes. The potential difference between 20 em distant was 175 V at 37.67 kA, and it corresponds to 875 V between 1 m distant. The amount of charge flowing a passenger at 100 kA impulse current can be estimated to $0.31\;mA{\cdot}s$. This is much less than the limit amount of charge for human body, $30\;mA{\cdot}s$ which is presented by Koeppen and Osypka.

• 조명전기설비학회논문지
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• 제23권9호
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• pp.117-123
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• 2009

최근 전력설비의 품질 향상과 시스템 운영기술의 발전으로 전력설비 자체의 고장은 낮은 수준으로 억제되고 있어, 상대적으로 바람이나 낙뢰와 같은 자연재해에 의한 고장이 차지하는 비중이 증가하는 추세이다. 특히, 낙뢰에 의한 고장을 억제하기 위해서는 효과적인 절연설계가 필요하며, 이를 위해서는 여러 가지 과전압해석이 필수적이다. 낙뢰에 의한 과전압해석을 위해서는 낙뢰특성에 대한 기본데이터와 이의 분석된 결과가 필요하다. 본 논문에서는 체계적인 낙뢰대책 수립을 위해 도입된 한국전력공사의 낙뢰관측시스템인 KLDNet(Kepco Lightning Detection Network)의 낙뢰관측 정보를 이용하여 낙뢰발생분포, 낙뢰의 다중도, 연간낙뢰일수, 대지낙뢰밀도, 낙뢰전류의 크기 등 절연설계에 필요한 기본 자료에 대해서 통계 처리하여 분석하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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• pp.151-159
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• 2003

According to the records, approximately 50 percent of power failure were caused by lightning. Conventional fault preventive measures against lightning include reduction of the footing resistance of the tower, multiplication of overhead ground wires and unbalanced insulation of the double circuit transmission tower. In addition to these, transmission line arresters have been recently appeared as an alternatives. In this paper an unbalanced insulation method with transmission line arrester was assumed as another countermeasure against simultaneous double circuit trip of 154 kV transmission line by lightning strike. The lightning performance of line arrester was compared with conventional insulation concept using different numbers of porcelain and glass insulator. Larger numbers of insulator simply increase flashover current level by lightning but the lightning performance doesn't proportional to it. EMTP simulation and predictive calculation of lightning failure rate were carried out to evaluate the performance.

• 조명전기설비학회논문지
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• 제16권4호
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• pp.38-45
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• 2002

내본 논문에서는 뇌서지에 의해서 발생하는 컴퓨터를 비롯한 전자기기의 장해에 대한 보호대책을 제안하기 위해서내 국내의 뇌보호설비에 대한 규격과 지침에 대한 기술적인 문제점을 분석하였다. 인하도선의 설치방법에 따른 인하도선과 인입용 금속관을 통하여 흐르는 전류사이의 관계를 검토하였으며, 인하도선계에 미치는 표피효과의 영향을 평가하는 실험을 수행하였다. 그 결과 인하도선을 인입용 금속관에 전기적으로 접속한 때 인하도선과 금속관은 하나의 도체로 작용하며, 표피효과와 쵸킹효과 때문에 뇌격전류는 인하도선보다도 금속관을 통하여 훤씬 많은 전류가 흘렀다. 따라서 뇌격전류에 의한 인하도선의 전위상승으로 야기되는 정전유도와 측면방전 등의 악영향을 억제하기 위해서는 인하도선을 인입용 금속관과 건물의 철골 구조체에 전기적으로 접속하는 것이 매우 효과적이다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권11호
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• pp.532-537
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• 2006

Lightning induced faults accounts for more than 66% at the transmission lines of KEPCO. The lightning causes damages to power system equipments including transmission line, the blackout of electricity and the electro-magnetic interference. Because of this reason, we need the real time lightning information for the optimal operation of power system. And, it is required to obtain and accumulate the lightning current parameters for the insulation design. In 2005, KEPRI constructed a lightning detection network, the KLDNet (i.e. Kepco Lightning Detection & Information System) and launched a lightning information service for KEPCO customers. It is intended to provide data service on the operation of transmission lines and collect lightning-related data, which is the most important factor regulating power system design and operation. The new system will replace LPATS, the old detection system, which has been operating since 1995 and is rapidly failing in terms of both detection performance and location accuracy. The purpose of this paper is to explain the work performed and the results of that work in performing a site survey of several locations. The purpose of the site survey is to find locations acceptable for the installation of a lightning location receiver in support of a Lightning detection system(LDS). A restriction was placed on the surveyed locations, as they must belong to the Korea Electric Power Company. This requirement was made to facilitate the communication needs of the LDS network. Total of 15 sites were evaluated as possible LDS sensor sites. Some of the sites were rejected for physical reasons and therefore no electrical testing was performed. Of the 15 sites, total of 10 sites were considered acceptable and 5 sites were rejected for various reason. In this paper, we would like to explain the site survey and detection efficiency for LDS.

• 한국안전학회지
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• 제31권3호
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• pp.47-52
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• 2016

This paper describes the design and fabrication of high frequency ground impedance measuring system for assessment of grounding system for Lightning protection. The ground impedance measuring system has been designed and fabricated which makes it possible to assess the ground impedance by frequency ranges from 100 Hz to 1 MHz. The effective grounding systems having a very low impedance to electromagnetic disturbance such as lightning surges and noises in microelectronics and high-technology branches are strongly required. In order to analyze the dynamic characteristic of grounding system impedances in lightning and surge protection grounding systems, it is highly desirable to assess the ground impedances as a measure of performance of grounding system in which lightning and switching surge currents with fast rise time and high frequency flow. The measuring system is based on the variable frequency power supply and consists of signal circuit part, main control part, data acquisition and processing unit, and voltage and current probe system. The ground impedance measuring system can be used to assess grounding system during occurrence of lightning.