• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.8
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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.

• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.602-608
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• 2016

Because of the random characteristics of lightning, the Monte Carlo method is applied to estimate the flashover rate due to lightning, however, the simulations using previous methods are difficult to both beginner and expert in power corporations. Therefore, this paper proposes the new and easy method to simulate the flashover rate by connection of electromagnetic transients program (EMTP) and MATLAB. The magnitude of a lightning strike is based on a curve measured in the field, while the classification of direct and indirect lightning depends on the striking distance. In a Korean distribution system, the flashover rate induced by lightning is simulated using proposed method. Simulations of the footing resistance according to the existence of an overhead ground wire (OHGW) are performed and the simulation results are discussed. The simulation results are compared with findings obtained with the IEEE Flash 2.0 program.

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.355-357
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• 2002

Distribution lines are spanned on a much large area as compared to transmission lines, and therefore, are more often susceptible to lightning strokes. The selection of the proper value of basic insulation level(BIL), for particular insolation components of distribution structures in specific, is very important. Lightning strikes has current risetimes ranging from 0.1 to several $\mu s$ and can produce transient overvoltages substantially greater than the BIL of many distribution systems in spite of lightning arresters. This paper describes lightning overvoltage of a 22.9kV distribution system due to lightning strike. This study will provide the information on insulation coordination studies to adopt BIL.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.500-503
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• 2006

This paper gives a Wireless lightning detecting and warning system. This system composed of transmitter and receiver. It promptly senses lightning strikes on the power lines and transmission towers by using the lightning current detection circuit in a small transmitter situated on the top of power tower, and it sends the number of lightning strikes and the ID. of the tower to patrols through the receivers. This system will be used to discover the exact location of a lightning strike.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.107-114
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• 2010

Lightning is the discharging of high-voltage charged cells within clouds to earth other or to the earth. Lightning protection grounding is essential for the protection of buildings, distribution lines, and electrical equipment from lightning surges. Equipment grounding is for the purpose of controlling the voltage to earth within predictable limits. This paper investigates the effects of lightning arrester grounding resistance by analysing the neutral to earth voltages and arrester break down voltages when the lightning strike hits the distribution line. The case study was simulated numerically and graphically through the use of the EDSA software program.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.4
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• pp.130-140
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• 2017

Lightning protective design of an aircraft fuel system is closely related to the safety of the flight. Recently, composite material in building an aircraft becomes more important because it can reduce the weight of the aircraft. The composite materials decrease the protection against the effect of lightning. Lightning protective design of metal material aircraft has been researched for a long time and the design technique has been announced widely. However, research on the lightning protective design using composite material aircraft is very limited. In this study, lightning protective design for fuel tank structural component, access cover, fuel filler cap and drain valve in carbon fiber composite material aircraft have been presented. To show the compliance with FAA airworthiness standard regarding the presented protection designs, three steps, including lightning strike analysis, lightning environment analysis and certification test, were conducted in accordance with FAA AC 20-53.

• Proceedings of the KIEE Conference
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• 2003.10a
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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.

• Korean Journal of Logic
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• v.22 no.2
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• pp.233-251
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• 2019

In this paper, I raise objections to Sungsu Kim's argument that Sartorio's hard-line reply to the manipulation argument fails. In attacking Sartorio's argument, Sungsu Kim claims that there are two problems with Sartorio's. I argue that Sungsu Kim's argument fails by responding to these two problems. With respect to the first problem, I provide a new example of dilution of responsibility. With respect to the second problem, I argue that, contrary to what Sungsu Kim assumes, for Sartorio's argument to succeed, our intuition that Ernie is responsible in the Lightning Strike Scenario does not have to be as strong as our intuition that Ernie is not responsible in the Diana scenario.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.2
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• pp.70-75
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• 2006

Owing to the strike of lightning a breakage of insulator would happen. This breakage may give rise to many problems such as increment of reclosing failure, a drop for reliance and a hardship of maintenance and repair. To solve those problem, this study develop a protected equipment for insulator which is suitable to 22.9[kV] distribution line towers and is purposed to investigation for a Proper adaption, Protection efficiency of insulator and effect of adaption.

• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.247-259
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• 2005

The interactions of natural atmospheric electricity with aircraft reveals many flight safety problems. It is estimated that on average, each commercial airplane is struck by lightning more than once each year. Thus the lightning strike to aircarft poses an appreciable threat to flight safety. Upset or damage of electrical and electronics equipment by the induced voltages is defined as indirect effect. The protection of aircraft electronics from the indirect effects of lightning can be accomplished first by determining the specific threats to the aircraft and systems contained within, and second, by designing protection methods to the aircraft components.