• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.5
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• pp.847-853
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• 2010

This paper describes switching surge analysis for reclosing decision in 345kV combined transmission line with XLPE power cable. Reclosing operation should be decided based on the detailed technical analysis in combined transmission line because this line includes power cable section which is week on insulation. Insulation of power cable can be breakdown at the week point in case of reclosing moment. Therefore the detailed analysis has to be carried out by considering several conditions such as length ratio of power cable section, arrestor, inserting resistance, charging rate, grounding resistance, etc.. On the other hand sheath voltage on IJ(Insulated Joint) is analyzed to check dangerous condition on cable cover. Analysis is performed by EMTP/ATP. Analysis results show that reclosing can be operated as the single line-to-ground fault occurs on overhead line in 345kV combined transmission line, if the inserting resistance is considered before the operation of main circuit breaker.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.286-286
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• 2009

According to previous report, aged sleeves for old transmission lines have various defect such as biased installation or corrosion of steel sleeve. These defects can cause serious accidents such as rapid increasing of sag or falling out of overhead conductor from sleeves. Moreover, the defects have been limited power capacity of transmission line. This paper study on mechanical and thermal behavior of ACSR $410mm^2$ conductor and sleeve with various defect model. The conductor has been aged artificially for 50 years. The detailed results were presented in the text.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.477-479
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• 2000

This paper presents an analysis which compares the effectiveness of different temporary safety grounding methods on working overhead distribution system. The analysis studied direct energization at fault conditions with seven scenarios. The results show that the scenario, single point safety grounding on the working pole with brackets Pairs spaced 2 km apart on both side of a work site is safest grounding method. This can be used to evaluate lineman safety on a overhead distribution systems in Korea.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.274-275
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• 2006

The IEEE std 738 and Cigre Electra documents are well known as the standard of calculating the ampacity of overhead conductors. Although these two standards use the same basic heat balance concept, they use different applicable methods to calculate ampacity ratings. This paper examines the concept of basic heat balance equation and the differences of each term of basic heat balance equation.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.2
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• pp.104-110
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• 2004

This paper describes the lightning overvoltage occurred differently according to installation methods of arresters and overhead grounding wire in case of double circuits distribution systems. First, the analysis models are established considering the severe case between upper and lower distribution line, when the direct lightning surge strikes to the overhead grounding wire. The lightning overvoltage is variously analyzed with the change of grounding interval and resistance, arrester installation interval as well as the magnitude of surge using EMTP. After simulation results are compared with the BIL which is now used at field, the authors propose the methods for suitable shielding in domestic distribution systems.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.445-446
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• 2008

With the semiconductor industry evolving into the deep sub-micron (DSM) era, the crosstalk effects on interconnect lines of a chip have increasingly caused a major bottleneck for design closure. In this paper, we propose an effective design guide line to reduce cell area overhead without crosstalk noise violations by using crosstalk prevention flow with clock shielding.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.5
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• pp.461-467
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• 2011

This study aims to create a numerical analysis model which can investigate the dynamic interaction between pantograph and overhead contact wire used for a high-speed railway vehicle, and validate the simulation results according to EN 50318 standard. Finite element analysis models of pantograph and overhead contact line are created using SAMCEF, a commercial FE analysis program. The mean, standard deviation, maximum and minimum values of contact forces are obtained. The simulation results are validated according to EN 50318, and the possibility of simulating the collecting characteristic of an actual pantograph system by using the developed model is discussed.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1207-1208
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• 2008

Forest Fire can cause a serious damage to overhead conductors. Therefore, the detailed investigation for the changes of mechanical and electrical properties of damaged conductors should be carried out to understand the effect of forest fires on conductors. This is very much important to maintain transmission line safely. Especially, this paper describes the changes of mechanical and electrical properties of conductor due to forest fire and agents. The detailed will be given in the text.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.210-212
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• 2001

The protection of underground cables against transient overvoltages resulting from lightning and other causes is important in cable-tine which is connected with overhead line and underground cable. This paper investigates the failure of CCPU(Cable covering Protection Unit) and presents improved configuration method of CCPU in underground cable system EMTP(Electromagnetic Transient Program) is used in order to study the overvoltages and modeling of components of the system such as overhead lines, underground cables, CCPUs and towers in presented.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1678-1680
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• 1998

The purpose of this study is to obtain optimum arrangement of phase conductors in minimizing magnetic field from overhead transmission lines. Data of the transmission lines rated 345 kV of the KEPCO(Korea Electric Power Company)'s system were used. For a three phase-double circuit transmission line, low-reactance arrangement is optimum in minimizing magnetic fields. For a three phase-four circuit, optimum phase arrangement is a-b-c-b-a-c(lower two circuits, clockwise)/b-c-a-c-a-b(upper two circuits, clockwise).