• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1186-1188
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• 1999

When we perform the test related to the power distribution system such as artificial fault test, protective coordination test, distribution automation test in short length test line, Lumped Constant Circuit, a kind of variable impedance, should be attached to the test line in order to make it equivalent to a real line in length electrically. In this paper we designed the positive sequence and zero sequence Lumped Constant Circuit with optimized inductor and resister for the modification of long, 16km, distribution line, when they are attached to the short, 4km, distribution test line.

• Journal of Power Electronics
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• v.4 no.4
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• pp.256-260
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• 2004

A new communication system is suggested using a single-phase full-bridge inverter with high efficiency ferrite core for power line communication (PLC). The conventional system has a decreasing signal voltage problem due to internal resistance. The proposed system has almost zero internal impedance and replaces a linear amplifier.

• Journal of the Korean Society of Safety
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• v.29 no.5
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• pp.29-34
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• 2014

The live line working is inherently dangerous as the workers have to work under the risk of electrical shock and most of works are carried out at height. The live line working need the some specific techniques and higher level safety measures such as a risk assessment to carry out works safely, but the electrical construction companies performed live-line working are usually small-sized companies. They have less capacity to have own safety management system. This study intended to conduct an in-depth analysis on the cause of electric shock accidents to provide basic data for policy proposing taking into considering the past eleven years for a long-term plan. And the aim of this study is to propose the policy about the equipment performance standards and/or worker's safety standards to revise the standards for preventing electric shock accidents, moreover, co-relation of the electrical work order form and on safety workings, especially electrical construction company/work.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.359-361
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• 2005

This paper presents the method of countermeasures before voltage collapse by load encroachment(impedance of load ability on R-X locus decrease toward zero point) and describes a study of impedance relay(zone-3) operation and voltage instability caused by over load of neighborhood line at contingency of heavy load line.

• Proceedings of the KIEE Conference
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• 2006.05a
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• pp.5-7
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• 2006

In this paper, developed a uninterruptible hotline tools and method for replacement of strain pole crossarm on overhead distribution line. For practical use of developed tools, following direct hot-line methods were proposed: 'Direct hot-lire method for replacement of pin pole crossarm', 'Direct hot-line method for alteration of crossarm' and 'Crossarm replacement method in uninterruptible cable displacement area'. These methods were proposed more simple and safe working on hotline job.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.281-287
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• 2006

Subway line becomes an important way of transportation as road traffic goes to limit. Recently the large number of passengers of the subway lines near metropolitan area, In-Cheon, Su-Won, Pyung-Teak and Chon-An, is rapidly increasing. The electric cars of the No. 1 subway line in the suburbs are now running fast compared to the downtown area. However, the fast electric car can be uncomfortable to ride in, because there are so much noise and vibration. In this research, the running characteristics of the electric car of the No. 1 subway line in the suburbs is investigated through the measurements of the noise and vibration at running condition.

• Journal of the Korean Society of Safety
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• v.11 no.3
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• pp.75-80
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• 1996

This paper presents a study on characteristics and safety for human body in ELF electric and magnetic fields using statistical method. The magnetic fields from a power line can be computed given a knowledge of the currents, voltage and geometry of the line. In this paper, a statistical method for predicting the magnetic fields given the inherent indetermination of the currents is presented. But the electric field is calculated given a knowledge of the voltage and geometry of the line. The effect of unexpected fluctuations in current is modeled by the Monte Carlo simulation. The suggested method is applied to the 345kV and 765kV transmission line system, the result shows that the maximum electric and magnetic field intensity is 6.8627kV/m and 284mG in 345kV system, 2. 5590kV/m and 35mG in 765kV system, respectively.

• Proceedings of the KIEE Conference
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• summer
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• pp.73-75
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• 2004

This paper presents the ability and the application of software packages for distribution planning which are DISPLAN(Distribution Planning System) and DLPLAN(Distribution Line Planning System) developed in KEPCO. After calculating size and position of maximum load by administration section for distribution, it forecasts the demand of distribution load considering growth location, increment, new load plan, etc of load by annual. Also it calculates distribution loss, voltage drop using modeled distribution line by you, and support for establishment and enlargement plan of substation and distribution line, decision of most optimal path. And it presents the abstract of used algorithm to develop this system.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1426-1430
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• 2009

AC AT feeding method consists return circuits of electric train inserting in parallel between trolly line and feeding line and connecting neutral line to rail and FPW. Due to increasing electric load at feeding system, collecting voltage of train and end voltage are going down. So to increase voltage between trolly line and rail, the usefulness of new autotransformer are considered which variation of short impedance and change of line voltage is simulated with modified winding ratio of autotransformer from 1:1 to variable tab.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.696-698
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• 2007

As overhead transmission lines are exposed to the outdoor weather, lightning induced fault accounts for about 66% of faults in transmission lines. The lightning may cause the damage of power system apparatus or the shut down of electricity. Not only in order to decrease the damage of the power system itself but also to ensure the reliable power supply, an appropriate insulation design based on the long-term lightning statistics is required. Meanwhile, real time information of lightning might be more useful to quickly locate the point of lightning induced fault in the line, leading to minimization of the adverse effects derived from the fault. Korea Electric Power Corporation has been providing an on-line lightning information service, named as KLDNet, since 2006 in order to meet the need inside our company. This paper describes the development and application of the information system.