• Title, Summary, Keyword: Lightning

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Lightning Characteristics and Lightning Rate Evaluation of Wind Farm by Lightning of Jeju Island for 2008-2012 (2008-2012년의 제주지역 낙뢰 특성 및 낙뢰에 의한 풍력단지 낙뢰율 평가)

  • Han, Ji-Hoon;Ko, Kyung-Nam;Huh, Jong-Chul
    • Journal of the Korean Solar Energy Society
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    • v.33 no.5
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    • pp.60-68
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    • 2013
  • This paper presents the characteristics of lightning over established and scheduled wind farms of Jeju island as well as over specific range of entire Jeju Island. The lightning data for 5 years from 2008 to 2012 was obtained from IMPACT ESP which detects lightning. Lightning frequency, lightning strength and regional lightning events were analyzed in detail, and then the lightning maps of Jeju Island were created. The evaluation of lightning rate was made for all the wind farms of this study. Damage to wind turbines by lightning was found in the existing wind farms. As a result, the eastern part of Jeju Island had more lightning frequency than the western part of the Island. Also, the evaluation of lightning rate was good for all established and scheduled wind farms of Jeju Island. Hankyung is the best place for lightning safety, while precaution should be taken against lightning damage in Kimnyung. Lightning damage to wind turbines occurred in Samdal and Haengwon wind farms, which had the first and the second highest lightning rate of the five existing wind farms.

Characteristics of Lightning Occurred over Jeju Island for 2004-2006 and an Effect of Lightning on Wind Turbine Generator System (2004-2006년에 발생한 제주지역의 낙뢰 특성 및 풍력발전기에 미치는 낙뢰의 영향)

  • Ko, Kyung-Nam;Kim, Kyoung-Bo;Huh, Jong-Chul
    • Journal of the Korean Solar Energy Society
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    • v.28 no.1
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    • pp.83-89
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    • 2008
  • This paper presents the characteristics of lightning pver Jeju island and a case of emergency stop of a wind turbine due to lightning. Using the IMPACT ESP sensor to detect lightning, the data on lightning frequency, lightning strength, regional lightning event were obtained and analyzed in detail. The measurement period was for 3 years from 2004 to 2006. As a result, lightning occulted the most frequently in July and August. As for lightning strength, lightning with grades -4 to -6 and +3 to +5 occur ed more frequently. The eastern part of Jeju island had much more lightning frequency compared with the western part of it. Lightning with high grade occurred mainly in offshore site and the coastal region. Furthermore, the data on wind turbine stop caused by lightning was analyzed. Although wind turbine lightning damage was not much in this study, the investigation on lightning damage or lightning faults to a wind turbine should be conducted in Korea to increase availability of wind turbine.

Study on Enhancing Lightning Protection Scheme of Catenary in Subway Viaduct Section

  • Li, Rui-Fang;Chen, Kui;Chen, Li-Sheng;Cao, Xiao-Bin;Wu, Guang-Ning;Zhang, Xue-Qin
    • Journal of Electrical Engineering and Technology
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    • v.12 no.2
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    • pp.950-958
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    • 2017
  • Viaduct increases the height of subway catenary, namely magnifies lightning attraction scope that lead to higher possibility of suffering lightning stroke. Therefore, it is necessary to analyze performance of lightning striking to catenary of subway in viaduct section and propose an improving lightning protection scheme. In this paper, using ATP-EMTP simulation software to establish an associated model to evaluate lightning withstand level of catenary with existing lightning protection schemes including arrester and grounding point, an improving lightning protection scheme is proposed - every pillar ground earth and arresters are installed with some installing spacing between 200m to 400m based on lightning damage degree and reliability requirements - according to analyzing results: while lightning withstand level is lowest for lightning striking to the neutral pillar, lightning withstand level is greatest for lightning striking to the both-ends pillar that arrester and grounding point are both installed; grounding point could obviously improve lightning withstand level for lightning striking to ground wire while arrester could obviously improve the lightning withstand level for lightning striking to catenary; every pillar ground earth could enhance the lowest lightning withstanding level up to 2.5 times than of that pillar ground earth across every 200m.

Statistics of Casualties and Damage Caused by Lightning Strikes in Korea from 2000 to 2007

  • Kim, Dong-Seong;Lee, Bok-Hee;Jeon, Duk-Kyu
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.7
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    • pp.14-19
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    • 2009
  • This paper presents statistics on lightning-caused damage to humans, structures, and electrical and electronic equipment. To reduce the number and amount of casualties and damage caused by lightning strikes, the statistical analysis of lightning-related damage reports is important in establishing lightning protection measures. The statistics of lightning death, injury and damage in Korea from 2000 to 2007 were primarily derived from mass media As a result, the annual average of lightning-caused deaths in Korea is about 5. Most lightning casualties involve people who work outdoors such as farmers and recreationists. Data on lightning-caused injuries to humans and damage to structures in this paper may be underestimated since the available data from mass media are incomplete. The actual lightning-caused casualties and damage in Korea may be greater than those presented in this paper.

Statistics on the Present Status of Installations of Non-conventional Lightning Rods (일반형이 아닌 피뢰침의 설치 실태에 대한 통계적 조사)

  • Lee, Bok-Hee;Lee, Seok-Yeon;Lee, Su-Bong;Baek, Young-Hwan;Lee, Kyu-Sun;Kim, Dong-Sung
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • pp.347-350
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    • 2006
  • The conception of early streamers is in sufficient and inadequate as a parameter for the determination of any advantage of early streamer emission(ESE) lightning rods versus ordinary lightning rods. Thus, standards for many other national and international lightning protection as well as KS C IEC 61024-1 do not take ESE lightning rods, charge dissipation systems or non-conventional lightning rods. Unfortunately, many non-conventional lightning rods such as ESE lightning rods and charge dissipation systems in Korea are increasingly used in lightning protection of structures including explosive manufacturing buildings, electric generating, transmission and distribution systems. This study attempts to make aware of no advantage of ESE rods and other non-conventional lightning protection systems and to investigate the present status of installations of ESE lightning rods.

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A Comparative Study on Lightning Characteristics and Lightning Damage to Wind Turbines of Jeju and Gangwon Region (제주와 강원 지역의 낙뢰특성 및 풍력발전기의 낙뢰피해 비교 연구)

  • Yang, Dal-Seung;Kim, Kyoung-Bo;Ko, Kyung-Nam
    • Journal of the Korea Society For Power System Engineering
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    • v.18 no.5
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    • pp.137-143
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    • 2014
  • An investigation on lightning characteristics and damage to wind turbines was performed on Jeju and Gangwon regions. The lightning data from January 2010 to September 2013 detected by IMPACT ESP were collected and analyzed in detail. Hangyeong and Seongsan wind farms of Jeju province and Taebaek, Changjuk, Taegisan and Gangwon wind farms of Gangwon province were selected for this study. Lightning rates and lightning damage events at the six wind farms were compared with each other. Lightning maps for the two regions were drawn using lightning frequency data. As a result, lightning frequency of Gangwon region was higher than that of Jeju region, while lightning strength of Gangwon was weaker than that of Jeju. Lightning rates were assessed to be good for all of the six wind farms. No lightning damage to wind turbines occurred at the two wind farms of Jeju, while some lightning damage to wind turbines took place at the four wind farms of Gangwon.

Certification of Structure Damage from Direct Lightning (항공기 집접낙뢰에 대한 동체 구조손상 인증)

  • Lee, Haesun
    • Journal of Aerospace System Engineering
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    • v.6 no.3
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    • pp.13-18
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    • 2012
  • Every 3000 hour an aircraft is stricken by a lightning. Also the lightning damage to the aircraft during flight are continually occurred due to extreme weather phenomena such as global warming. Under the airworthiness standards, the aircraft must be designed to protect lightning. To show compliance for lightning, the test should be conducted by the actual lightning current and voltage waveform for the actual aircraft or parts. After test, structure damage is detected via visual inspection or NDI. Structure substantiation for damage is to show retaining limit or near limit load capability. This is conducted by test or analysis based on test. Thus, the aircraft should retain structural strength to land safely, even though the damage of aircraft fuselage from Lightning strike are occurred.

A Study on the HEC(Hybrid ESE-Conductor) Method for Lightning Protection of Buildings (건축물의 낙뢰보호를 위한 HEC(Hybrid ESE-Conductor) 방식에 관한 연구)

  • Kim, Dong-Jin;Kim, Young-Sun;Lee, Ki-Sik
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.57 no.2
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    • pp.146-152
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    • 2008
  • The frequency of lightning is increased due to improbable weather condition and global wanning. This phenomenon increases economical damage as well as human damage. Advanced countries like europe and north america have applied the facility standard of lightning by accumulating a store of quantitative data about lightning research. Lightning facility is composed of the lightning accepting part for induction lightning, ground connected electrode which conducts lightning current. The lightning accepting part is composed of normal rod, horizontal conductor, ESE lightning rod. Moreover, lightning accepting part is taken to use by the method of protection. This paper suggests HEC(Hybrid ESE-Conductor) method which mixes horizontal conductor and ESE lightning rod. This is also discovered by experiment that the starting point of corona discharge current is low, so it is efficient for lightning protection comparing with other methods. Moreover, distribution of electric field is analyzed qualitatively by finite element method. It also results in the relation of the starting point of corona discharge current. Corona discharge current makes minute current about some ${\mu}A$ between the electrodes by the strength of electric field. Also it occurs insulation destruction of gas, and it is developed to the shape of streamer by increase of the strength of electric field. We can find that the initial occurrence of streamer and contact probability of lightning can have advantage after researching the starting point of corona discharge current and discharge current of lightning striking point. This research demonstrates that the suggested HEC method is economically competitive as a lightning protection facility, and it takes a capably perfect role.

Characteristic Changes of ZnO Arrester Blocks by Multiple-lightning Impuse Currents (다중 뇌충격전류에 의한 산화아연형 피뢰기 소자의 특성 변화)

  • Gil, Gyeong-Seok;Han, Ju-Seop
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.49 no.12
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    • pp.685-690
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    • 2000
  • Multiple-lightning impulse currents are a general feature of the lightning ground f=flash. It is therefore necessary for lightning arresters used in power systems to be estimated by applying not only a single-lightning impulse current but also a multiple-lightning impulse currents. This paper presents the effects of multiple-lightning impulse currents on deterioration of ZnO arrester blocks. The multiple-lightning impulse generator which can produce quadruple 8/20$[\mus]$ 5[kA] with separation time of 30~120[ms] is designed and fabricated. The total energy applied to the arrester block at each impulse is about 1,200[J]. In experiment, various parameters such as leakage current component, reference voltage, and temperature are measured with the number of applied impulse current. Also, micro-structure changes of the ZnO blocks after applying the single and the multiple-lightning impulse currents of 200 times are compared. The experimental results indicate that the types of arrester blocks are more vulnerable to deterioration or damage by multiple-lightning impulse currents.

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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.