• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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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.

• 대한전기학회논문지:전력기술부문A
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• 제53권8호
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• pp.454-460
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• 2004

The effects of surge arresters for protection of transmission systems against direct lightning strokes have already been reviewed using Electromagnetic Transients Program(EMTP). Distribution lines are spanned in much larger area than transmission lines, and therefore, are more susceptible to lightning strokes. We have modelled the 22.9kV underground distribution cable systems that have arresters and grounding wires. And this paper analyzes the overvoltages on underground distribution cable systems when direct lightning strokes strike on the overhead grounding wire using EMTP. Then we investigated that (1) the effects of lightning stroke according to underground distribution cable length (2) voltages at the riser pole and at the cable terminal according to installation of arrester. This study will provide insulation coordination methods for reasonable systems design in 22.9kV underground distribution cable systems.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권3호
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• pp.91-98
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• 2003

The importance of improving the quality of electric power is being strongly raised, owing to an increasing use of sensitive and small-sized electronic devices and systems. The transient over-voltages on low-voltage power distribution systems are induced by direct or indirect lightning return strokes. These can cause damage and/or malfunction of the utility systems for home automation, office automation, factory automation, medical automation, etc. The behaviors of lightning overvoltages transferred through the transformer to the low-voltage distribution systems using a Marx generator were experimentally investigated. Furthermore, the coupling mechanisms of lightning overvoltages transferred to the low-voltage systems were clearly illustrated through a theoretical simulation using a Pspice program. The overvoltages in low-voltage ac power systems are rarely limited by the application of the surge arrester to the primary side of the distribution transformer. A superior surge protection scheme is to install surge protection devices at the service entrance switchboard and/or at the load devices in TN power systems.

• 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.

• KIEE International Transactions on Power Engineering
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• 제5A권4호
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• pp.366-370
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• 2005

To meet increasing power demand, 500 kV power systems are under consideration in the regions of some Middle Asian countries. As the power system voltage becomes higher, the cost for the power system insulation increases significantly. 500 kV transmission systems will become the basis of a region's power system and they require much higher system reliability. Consequently, by the methods of limiting overvoltages effectively, a reasonable insulation design and coordination must be accomplished. In particular, the Substations must be constructed to be of outdoor type. In order to determine the various factors for the insulation design, the EMTP (Electro-magnetic transient program) is used for the magnification of transient phenomena of the 500 kV systems in the planned network. In this paper, we will explain the calculation results of lightning overvoltages by the EMTP for lightning protection design for the 500 kV substations. To obtain reliable results, the multi-story tower model and EMTP/TACS model are introduced for the simulation of dynamic arc characteristics.

• 항공우주시스템공학회지
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• 제10권2호
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• pp.41-45
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• 2016

Statistical data show that a large aircraft(transport category) is struck by lightning once a year or once per 1,000 ~ 20,000 flight time. The protection design for lightning must be applied to the aircraft because an aircraft is developed on condition that it is absolutely struck by lightning. For the proper protection design, we need to understand direct effect and indirect effect of lightning. This paper described the direct effect of lightning on aircraft's structures and systems.

• 대한전기학회논문지:전력기술부문A
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• 제55권8호
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• pp.313-321
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• 2006

This paper describes the overvoltage obtained by surge behavior analysis in testing underground distribution systems. Model systems consist of overhead distribution line and underground cable. Such model system considered various characteristics of actual distribution systems will be soon constructed at testing yard. Simulation is carried out under various states such as cable kinds, cable length, lightning wave and time, and branch circuits. Model is established by EMTP/ATPDraw. Line Constants are calculated by ATP_LCC. When the direct lightning surge strikes on conductor of overhead line, the overvoltage is calculated using EMTP/ATPDraw in many cases. Simulation results will be compared with real testing results at testing yard in the near future. The compared results will be used to establish protection methods in actual underground distribution systems.

• 조명전기설비학회논문지
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• 제16권4호
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• pp.8-14
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• 2002

현대의 뇌보호시스템은 낙뢰로 인한 감전이나 건축물, 전기·전자기기의 파손과 같은 위험성을 제거하는 것이 요구되지만 종래의 뇌보호설비는 단지 인명의 피해나 건축물을 보호하는 것이 주된 역할이었다. 오늘날 컴퓨터, 정보통신설비 등을 효과적으로 보호할 수 있는 뇌보호설비가 필수적 요건으로 대두되었다. 본 논문에서는 뇌과전압으로부터 컴퓨터와 전자장비를 보호할 수 있는 기술을 개발할 목적으로 인하도선의 종류와 설치기법에 따라서 인하도선에 유도되는 전위상승 억제에 대한 연구를 수행하였다. 그 결과 인하도선의 전위상승에 의한 측면방전과 위험성을 줄이기 위해서는 인하도선으로 낮은 특성임피던스를 가지는 동축케이블이 적당하며, 인하도선과 금속관을 상단과 하단에서 본딩하는 방법이 효과가 높게 나타났다.

• 한국군사과학기술학회지
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• 제24권3호
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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.

• 조명전기설비학회논문지
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• 제24권6호
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• pp.67-74
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• 2010

국내의 저압수용가 대부분은 한국전력공사의 TN-C접지방식으로부터 공급받고 있으나 부하설비는 TT 접지방식을 위주로 한 전기설비기술기준에 따라 시설되어 있다. 본 연구에서는 정보기술설비를 뇌서지로부터 보호할 수 있는 적절한 전원계통접지방식을 제안하기 위해서 TT, TN계통의 뇌서지에 대한 보호성능을 연구하였다. 그 결과, 뇌서지가 배전계통의 중성선에 입사한 때 TT계통의 기기접지단자와 전원선의 중성점 사이에 높은 전위차가 발생하였으며, 예민한 컴퓨터설비가 손상될 위험성이 있으므로 TT계통은 적합하지 않다. 뇌서지로부터 저압 설비를 보호하기 위해서는 등전위본딩이 중요한 요건이며, TN계통이 중성선을 통하여 입사하는 뇌서지의 저감에 가장 우수하였으며, 수용가 인입구에서의 추가접지도 바람직한 방법이다.