• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1453-1454
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• 2007

A street light is an electrical equipment to improve the traffic safety and the security for people in night. However, many accidents due to electric shock have happened in recent, people were interested in the safety of electrical facilities. And people want to know the danger by touch and step voltages. When the electric power lines fall down on the ground, the fault current flows to ground rod and the potential near the ground rod is increased to induce the high touch and step voltages. In this paper, we installed different ground rods with a street light and investigated the electrical potential according to ground methods and the types of ground rod. Finally, we examined the electrical facilities with the experimental result and present the improved technical data for the safety from electric shock

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.337-340
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• 2008

When high surge voltage invaded into the ground rod contacted with ground water, the ionization phenomena are happened in the water. Although some researchers have surveyed the ionization phenomena in soil, they have just analyzed the variation of the ground resistance. The most important role of the ground rod is to elect human beings from potential rise and to dissipate energy to the earth safely. In this wort we presented the method evaluating the potential reduction and energy dispersion. Also we analyzed theses factors as a function of charging voltages at the water resistivity of $50\;{\Omega}{\cdot}m$ using the Matlab Program. As a result the ground rod potential was reduced to 38 kV by ionization just below breakdown voltage. The energy more than half of the total injected energy was dispersed through the grounding electrode caused due to ionization.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.290-292
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• 2003

The intake tower of D-dam located in a mountainous area positioned in the left side of the dam and its structure installed alone on the water surface then, can become target of direct lightening. To protect the intake tower from the direct lightening and indirect-lightening, lightening rod installed in the top area of the intake tower and ground pole laid under the surrounding ground. however, because the surrounding ground almost consists of a rock, it is very difficult to obtain the grounding resistance. It is main object to examine the construction plan of the optimum lightening rod equipment and ground pole with measuring the earth specific resistance of the around of the intake tower which is the scheduled area to lay the ground pole with the Wenner's 4-electric pole method and the Schlumberger's method. and using the analysis tool, ESII.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2006년도 춘계학술대회 논문집
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• pp.351-354
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• 2006

This paper deals with the potential interferences between ground rod and counterpoise. The ground potential rise and coefficient of potential interference were measured by using the hemispherical water tank grounding simulator and calculated from CDEGS program as functions of the configuration and size of grounding electrodes and the distance between grounding electrodes. The ground potential un and potential interference coefficient strongly depend on the distance between grounding electrodes, the arrangement and size of grounding electrodes.

• 조명전기설비학회논문지
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• 제24권1호
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• pp.136-144
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• 2010

봉형접지극은 우리나라 배전계통에 가장 많이 사용하고 있는 접지전극이다. 현재 배전계통에 사용하고 있는 봉형접지극은 접지동봉, 심타용접지봉 그리고 도전성콘크리트접지봉 등이 주로 사용되고 있다. 그러나 접지저항값은 토질에 따라 소정의 접지저항값을 얻기가 어려울 때가 많아 접지저항저감제를 사용하게 된다. 본 연구에서는 봉형접지지전극 중 가장 많이 사용하고 있는 접지동봉에 물을 제공하였을 때 얻어진 접지저항값을 기준으로 접지저항저감제의 사용방법(시공법), 접지저항저감제의 종류 등에 따라 얻어진 초기접지저항값, 시간경과(1년)에 따른 저항값의 변화폭 추이 등을 비교 검토한 연구이다. 본 연구 결과를 요약하면 신공법으로 접지저항저감제를 사용하였을 때 낮은 초기접지저항저감을 얻는 효과뿐만 아니라 시간경과에 따른 접지저항값의 변화폭도 적어 안정됨을 확인할 수 있었다.

• 조명전기설비학회논문지
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• 제20권1호
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• pp.65-70
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• 2006

본 논문은 임펄스전류에 따른 접지시스템의 과도 특성에 관한 것으로 임펄스 전류를 심매설 봉상 접지전극과 그리드 접지전극에 인가하였을 때 나타나는 과도접지임피던스를 조사하였다. 과도접지임피던스는 인가전류의 상승시간과 접지전극의 크기 및 형태에 강하게 의존하며, 접지전극의 인덕턴스는 짧은 시간 영역에서 접지시스템의 과도 접지임피던스에 크게 영향을 미치는 것으로 나타났다. 또한 심매설 봉상접지전극은 짧은 시간영역에서 과도접지임피던스를 줄이는데 효과적이었다.

• 조명전기설비학회논문지
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• 제23권7호
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• pp.41-48
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• 2009

Grounding impedance depends on the frequency of current flowing into a grounding system lightning in particular has a broad frequency spectrum from some tens of Hz to a few MHz. So the grounding impedance related to transient currents such as lightning should be measured. In this paper, the grounding impedances of vertically-driven ground rods of 10, 30 and 48[m] long are measured and analyzed as functions of the frequency of injected current and the feeding point. As a result, the longer the ground rod is, the lower the steady-state ground resistance is. However the grounding impedance of a vertically-driven ground rod at a high frequency is significantly increased. It is not always true that low grounding impedance follows from a low steady-state ground resistance. It is important to evaluate the high frequency performance of grounding systems for protection against lightning.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.155-157
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• 1997

This paper presents the results of an experimental investigation of ground impedance in the low frequency region regarding the transiant state on the soil and ground electrodes(rod, electric rod with needles, electric mesh). The grounding resistance playing an important part in substation grounding designs is measured. Especially, the reduction effect of ground impedance by using the electric rod with needles in the soils are presented.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2004년도 학술대회 논문집
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• pp.247-250
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• 2004

A ground resistance is a good index of performance in a grounding system, but it does not reflect the performance in transient states. Recently long vertical ground rods in urban areas are often installed. But because of the inductance of long ground rods the ground impedance at high frequency might be greater than its resistance at low frequency. In this paper, a ground impedance of deeply driven ground rod has been measured in the frequency range from 10 kHz to 50 MHz. As a result, the ground impedances of a deeply driven ground rods are almost constant at the frequency range less than 100 kHz. However at high frequency the ground impedance showed the strong frequency dependance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1876-1878
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• 2004

A systematic approach of measurement, modeling and analysis of grounding system impedance is presented. The measurement and analysis system of ground impedance is based on a computer aided technique. The ground impedances of the ground rod are considerably dependent on the frequency. The ground impedance is mainly resistive in the frequency range of 3-20 kHz. At higher frequencies, the reactive components of the ground impedances are no longer negligible and the inductance of the ground rod was found to be the core factor deciding the ground impedance. As a consequence, the equivalent circuit model based on the measured data was proposed, and the calculated results were in approximately agreement with the measured data.