• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.9
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• pp.40-46
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• 2009

Although a ground resistance is a good index of grounding performance for grounding electrodes, it does not reflect the grounding performance during transient state. A copper rod electrode is the most commonly used grounding electrode in electric distribution systems. In this paper, the grounding impedance of copper rods has been measured in frequency raging from 60[Hz] up to 100[kHz] and an equivalent model of the grounding impedance is identified from the measured values. The grounding impedance under study when a typical lightning surge is injected into the grounding system was simulated numerically and graphically through the use of the MATLAB software program.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.6
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• pp.66-71
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• 2003

Electronic equipments made from integrated circuits and small-sized semiconductors is protected by surge protective devices(SPDs) such as ZnO varistors, Zener diode and gas discharge tube from lightning overvoltages. However the clamping voltage of SPDs is greatly influenced by the method of installing the SPDs. In this paper, the protective effects of SPDs according to types of system groundings were experimentally investigated. The separate grounding is a particularly undesirable way to install SPDs. The effectiveness of the common grounding point for ZnO varistors is more pronounced than that for gas discharge tubes. The common grounding at the terminal of SPDs is recommended as a best method of installing SPDs.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.371_372
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• 2009

This paper describes surge characteristics on 345kV combined transmission system mixed overhead line and GIL(Gas Insulated Transmission Line). Then, it is compared with the results of the system mixed overhead line and XLPE power cables. Finally the lightning overvoltages are also discussed according to surge arrester installation in two kinds of combined transmission systems when the lighting strikes on the phase conductor.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2183-2184
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• 2006

전력계통의 과도현상 분석용으로 개발된 수치계산 프로그램인 EMTP ( Electromagnetic Transient Program)를 사용하여 건물내에 낙뢰에 의한 뇌서지가 침입했을 때 건물 전체에 surge current가 어떻게 확산되어 가는지를 분석해 본다. 이러한 현상을 분석하기 위해서 건물의 등가회로를 ${\pi}$-회로로 구현하고, ANSI 규격에 맞는 뇌서지를 건물에 유입시켜서 그에 따른 건물 내부의 current 분포를 알아본다. 그리고, 건물 체적을 변화시켜 가면서 뇌 서지가 건물 내부의 전기기기에 미치는 영향을 해석해 본다.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.551-552
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• 2006

전력계통의 과도현상 분석용으로 개발된 수치계산 프로그램인 EMTP(Electromagnetic Transient Program)를 사용하여 건물내에 낙뢰에 의한 뇌서지가 침입했을 때 건물 전체에 surge current가 어떻게 확산되어 가는지를 분석해 본다. 이러한 현상을 분석하기 위해서 건물의 등가회로를 ${\pi}$-회로로 구현하고, ANSl 규격에 맞는 뇌서지를 건물에 유입시켜서 그에 따른 건물 내부의 current 분포를 알아본다. 그리고, 건물 체적을 변화시켜 가면서 뇌 서지가 건물 내부의 전기기기에 미치는 영향을 해석해 본다.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.347-348
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• 2008

This paper presents the use of Line Surge Arresters on 154kV double circuit lines. The ouatge rate which is highly related to the tower footing resistance is showed during the last a few year. The general methods that have been adopted at lines also are introduced. Lightning performance of lines without and with line surge arrester is studied and compared. The characteristics between air-gap type and gapless type LSA also compared. Line surge arrester installation strategy is presented.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.774-777
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• 1988

This paper covers the insulation coordination of 765 KV transmission line in Korea Electric Power Corporation. The design for the lightning, switching surge, and contamination was conducted to increase the reliability of 765 KV line. The authors have used the result of a limited Westinghouse ANACOM swiching surge study of the Korea Electric Corporation's 765 KV Expansion plan. The study investigated the switching surge overvoltage distribution and maximum switching overvoltage when relosing 765 KV lines. They used the technical data of the suspension insulator for the contamination design, which was available from a foreign insulator manufacture. From this paper, the authors find out that the contamination design dominates to determine the number of insulator and the SOV design dominates the air clearance in the tower. Afterwards the authors will confirm this design by Demonstration Test with Korea Electro-technology Research Institute.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.272-277
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• 1987

A probabilistic model to analyze surge voltage waves on a transmission conductor caused by lightning, strokes striking a transmission line tower has been proposed. In this proposed model, a probability apace has been constructed. Based on the constructed probability space, random variables denoting the voltage peaks, time to crest, and time to half have been generated. To know the statistics of surge voltage waves, it suffices to find out the cumulative probability distributions of these random variables. A illustrative numerical example to find out out the distributions of the random variables has been carried out using the Electromagnetic Transient Program(EMTP).

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1217-1218
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• 2006

전력계통의 과도현상 분석용으로 개발된 수치계산 프로그램인 EMTP(Electromagnetic Transient Program)를 사용하여 건물내에 낙뢰에 의한 뇌서지가 침입했을 때 건물 전체에 surge current가 어떻게 확산되어 가는지를 분석해 본다. 이러한 현상을 분석하기 위해서 건물의 등가회로를 $\pi$-회로로 구현하고 ANSI 규격에 맞는 뇌서지를 건물에 유입시켜서 그에 따른 건물 내부의 current 분포를 알아본다. 그리고, 건물 체적을 변화시켜가면서 뇌 서지가 건물 내부의 전기기기에 미치는 영향을 해석해 본다.

• Proceedings of the KIEE Conference
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• 2005.07e
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• pp.70-72
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• 2005

Electronic control systems adopted in water treatment facilities. And many water treatment facilities are operated by electrical and electronic devices or by remote control. So those are damaged by the surge which is generated by lightning inevitably. This study is intended to measure and analyze the SPD performance tests occurred at the electrical and electronic control devices and to show the methods of the reduction when the surge is occurred suddenly.