• Title/Summary/Keyword: lightning

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Review about the Lightning Protection System for Ground Facilities of Anti-aircraft Weapons System (뇌 보호시스템의 대공무기체계 지상시설 적용에 대한 고찰)

  • Jung, Kyoungwook;Shim, Donghyouk;Son, Donghyeop
    • Journal of the Korea Institute of Military Science and Technology
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    • v.24 no.3
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    • pp.339-347
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    • 2021
  • Recently, the incidence of lightning in Korea has been increasing more and more. The damage caused by lightning is also getting worse. Lightning protection system is a prerequisite, not a sufficient condition. Considering the characteristics of lightning, there is a high frequency of lightning strikes in highlands. So, high grades of LPS should be applied to ground facilities of anti-aircraft weapons systems. 4-Level LPS was applied on groung facilities of anti-aircraft weapons system based on lightning incidence rate in past. There are some possibilities of damage from lightning in anti-aircraft weapons system. So, we have to readjust the LPS level with grounding, lightning rods and surge protect device based on lightning incidence rate in now days. Propose 2-level LPS and design with lightning rods, surge protector, separated grounding in this paper.

A Study on the Statistical Analysis of Lightning Parameters by Lpats in Korea ('96~'98) (LPATS를 이용한 한반도 뇌격파라메터의 통계분포에 관한 연구('96~'98))

  • Woo, Jeong-Wook;Shim, Eung-Bo;Jung, Gil-Jo;Kim, Jung-Bu;Lee, Geon-Woong
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.49 no.5
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    • pp.310-314
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    • 2000
  • To study the basic research of the lightning parameters for power system operation, LPATS(Lightning Positioning and Tracking System) has been introduced since 1995 in KEPCO(Korea Electric Power Corporation). We have developed the lightning parameters analysis program which can produce accumulative magnitude distribution of lightning current and IKL map by LPATS data. We obtained the various statistical distributions of lightning current parameters since 1996 by the lightning analysis program for the pertinent insulation design. In this paper, we describe the LPATS system in KEPCO, the statistical distribution of lightning current parameters and the IKL(Isokeraunic Level) map from 1996 to 1998. And the compared results between the calculated LFOR(lightning flashover rate) and the observed rate are also described.

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Applicability of Messenger Wire for Purpose of Lightning Protection

  • Seo, Hun Chul;Han, Joon;Choi, Sun Kyu;Lee, Byung Sung;Rhee, Sang Bong;Kim, Chul Hwan
    • Journal of Electrical Engineering and Technology
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    • v.11 no.1
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    • pp.167-174
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    • 2016
  • The Korean distribution line currently consists of overhead ground wires (OHGW), overhead distribution lines, neutral wires (NW), and messenger wires (MW). The MW is installed under the NW. The lightning protection system in Korea is focused on OHGW and lightning arrester and the MW are not considered. Therefore, this paper proposes the applicability of MW for purpose of lightning protection. For this, we analyzed the effects of lightning overvoltage according to the existence of OHGW and MW and the grounding conditions of the MW in the Korean distribution system. The grounding conditions of the MW that we took into consideration were the common or separate grounding of the MW and NW. The analysis based on the equivalent circuit of the distribution pole at each condition was performed. The distribution lines and lightning were modeled using the Electromagnetic Transients Program (EMTP). For each of the installation conditions of the OHGW and MW, the various lightning conditions were simulated and analyzed for both direct and indirect lightning. The simulation results showed that, if the OHGW was not installed in the Korean distribution system, the lightning overvoltage could be reduced by the common grounding of the MW and NW.

A Study on the Robustness of the Bitcoin Lightning Network (Bitcoin Lightning Network의 강건성에 대한 연구)

  • Lee, Seung-jin;Kim, Hyoung-shick
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.28 no.4
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    • pp.1009-1019
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    • 2018
  • Bitcoin is the first application utilizing the blockchain, but it has limitations in terms of scalability. The concept of Lightning Network was recently introduced to address the scalability problem of Bitcoin. In this paper, we found that the real-world Bitcoin Lightning Network shows the scale-free property. Therefore, the Bitcoin Lightning Network can be vulnerable to the intentional attacks targeting some specific nodes in the network while it is still robust to the random node failures. We experimentally analyze the robustness of the Bitcoin's Lightning Network via the simulation of network attack model. Our simulation results demonstrate that the real-world Lightning Network is vulnerable to target attacks that destroy a few nodes with high degree.

How to Develop Lightning Arresters by Aircraft and Vessel Ships in Flying and Navigation (비행기나 선박은 여하히 낙뢰를 피하는 가에 대한 고찰)

  • 조규심
    • Journal of the Korean Professional Engineers Association
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    • v.31 no.4
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    • pp.64-68
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    • 1998
  • According to some statistics, about 13,000 passenger aircrafts are daily flying over the globe and these aircrafts are struck by a lightning flash at least once a year. But so far we have never heard lightning injured any passengers and crew members got shocked by lightning. The aircraft, lightning and the sky are inseparably related to each other. Accordingly, the aircraft and lightning are also inseparably related to each other. They say lightning is easily attracted to metals and these aircrafts are incidentally made of metal. Aircraft become statically and electrically charged when flying because of the friction with air. A lot of research and investigation to protect aircraft from the influence of lightening have been made since the early days. The following descriptions outline researches and investigations on how aircraft and ships get aways from lightning flashes during the flight or the sail. (Research and Investigation on Aircraft and Ships Get Aways from Lightning Flash)

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The new lightning detection system of KEPCO Lightning Detection & information Network (한전의 새로운 낙뢰측정 네트워크 KLDNet)

  • Woo, J.W.;Kwak, J.S.;Shim, E.B.;Won, B.J.;Moon, J.D.
    • Proceedings of the KIEE Conference
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    • 2006.07a
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    • pp.83-84
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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 shut down 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. A lightning detection system, LPATS, has been operated since 1995 in KEPCO. For the improved detection efficiency, we had in stalled the new lightning detection network named as KLDNet in 2005. Also, we had developed the new software for the lightning parameters analysis and real time information service on the WEB. In this paper, we would like to introduce about the new system.

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Analysis of Lightning observed by KEPCO Lightning Detection Network (한전낙뢰관측 시스템 KLDNet의 낙뢰관측 결과 분석)

  • Kwak, J.S.;Park, M.H.;Jeong, M.J.;Ju, H.J.;Oh, S.Y.;Kim, H.S.;Woo, J.W.;Han, K.S.;Goo, S.G.
    • Proceedings of the KIEE Conference
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    • 2015.07a
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    • pp.398-399
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    • 2015
  • The fault level of power transmission lines caused by natural disaster such as lightning and rainstorm has been on the rise. Especially, the cause of lightning stokes is large part of transmission faults. In order to reduce the lightning failures, it is necessary to measure and analyze the lightning characteristics. This paper deals with observation of the lightning strokes by KEPCO Lightning Detection Network(KLDNet) and analysis including lightning density, multiplicity and amplitude distribution.

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Lightning Risk Assessment for Structures Lower than 20m High (높이 20미터 미만인 구조물의 낙뢰리스크 평가)

  • Lee, Ju-Chul;Kim, Gi-Hyun;Lee, Young-Chul
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.26 no.12
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    • pp.21-27
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    • 2012
  • Korean Industrial Standards for lightning protection system complies with IEC standards. However, the standards are applicable only to buildings and structures more than 20 meters in high. Therefore, it is necessary to determine whether lightning protection system should be installed on structures lower than 20 meters high. This paper proposes an efficient method of assessing risk against lightning of structures lower than 20 meters high. The method suggests simplified lightning protection system and provides selecting an appropriate protection level. The suggested method assumes that structure under assessment has no lightning protection system and there is no person around the structure at the moment of lightning stroke. A simplified method of assessing the risk to human within the structure is developed by adopting the general assessment factor. The selection of a protection level is possible by comparing tolerable risk with physical damage risk caused by a direct lightning. Finally, this paper gives ways to establish surge protection measures when a structure with lightning risk is within a radius of 2km from the assessed structure even if this structure requires no lightning protection system.

A Study on the Risk of Lightning in Special Structures and its Verification Method (특수 구조물의 낙뢰 위험도와 검증 방안에 관한 연구)

  • Yoo, Jeong Hyun;Kim, Hei Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.6
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    • pp.664-668
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    • 2018
  • Free-standing structures that are especially high are more likely to receive brain attacks caused by lightning. Since special structures are generally part of national industrial structures, lightning strikes mostly cause socio-economic damage. Lightning protection facilities are installed to prevent such lightning damage, but in 2015, support cables on West Sea bridges were hit by lightning, causing a lot of economic damage. Accordingly, the design of a lightning protection system shall establish protective measures after analyzing the risk of debris falling onto the structure. In this thesis, lightning strikes are analyzed directly in relation to the modeling system that operates the actual information collection system for lightning strikes, depending on the location of the tall, free-standing structures, and practical lightning hazard information is provided by a meteorological station. In addition, we propose monitoring and applying a probability correction rate to the calculation of the lightning risk based on the number of lightning strikes directly reaching the ground in order to obtain an effective lightning risk assessment.

A Study on Investigation Method of the Electric Fire Scene Caused by Lightning (낙뢰로 인한 전기화재의 현장조사기법 연구)

  • Song, Jae-Yong;Sa, Seung-Hun;Nam, Jung-Woo;Kim, Jin-Pyo;Park, Nam-Kyu
    • Fire Science and Engineering
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    • v.25 no.1
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    • pp.50-56
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    • 2011
  • In recently years, occurrences of lightning return strokes have been increased by global worming effect and intensity of lightning impulse voltage and current accompanied by lightning discharges has being strengthening. In Korea, 560 thousand lightning discharges happened in 200S. According to the increasing frequencies of lightning, human deaths and damages to the structure have been increased steadily. Electric fire caused by lightning return strokes due to the breakdown between power line and ground line from the ground potential rise on a process of the lightning impulse current through to the ground. The damages of lightning were occurring at same time in the neighboring areas of the lightning point. In order to protect from the lightning stroke, we made a suggestion to use protection devices and equipotential bonding at the dangerous areas. The analysis results of electric fires caused by lightning would be utilized to investigate and to find accurate fire cause in the fire scenes.