• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.254-259
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• 2007

During the ground fault conditions, the flow of current to earth will produce potential gradients within and arround a substation. The common physiological effects of electric current on the body, stated in order of increasing current magnitude, are threshold perception, muscular contraction, unconsciousness, fabrillation of the heart. In this study, determined the tolerable voltage about earth-layered structure in the grounding system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.2046-2048
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• 2005

This paper deals with ground potential rise of structure grounding electrode when a test current flows through grounding electrode. In order to analyze the potential gradient of ground surface on structure grounding electrode, the reduced scale model has been used. The structures were designed through reducing real buildings and fabricated with four types on a scale of one-one hundred sixty. The supporter was made to put up with weight of structure and could move into vertical, horizontal, rotary direction. When a test current flowed through structure grounding electrodes, ground potential rise was the lowest value at electric cage type(type B). According to resistivity and absorption percentage in concrete attached to structure, the potential distribution of ground surface appeared differently.

• 한국안전학회지
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• 제29권6호
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• pp.46-48
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• 2014

This paper compared and demonstrated the performance of the earth plate for conventional type and early streamer discharging type developed a new plate in order to improve the performance of the ground plate for use in grounding. The results obtained are shown below; early streamer discharge earth plate was high 5 kV on DC flashover voltage and corona discharge current was higher than about 2 times under the same test conditions compared to the conventional earth plate. From the experiential result, streamer discharge earth plate had a function of rapid inflow/out flow than the general ground plane because of by corona discharge current to be generated in the sharp serrated in formed the ground plane when strike current occurred. In the future, the newly developed early streamer discharge ground plate would be beneficial for grounding work to be widely used to promote the convenience and economy of construction.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.440-445
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• 2007

This paper deals with assessment of risk component for electrical safety and investigation on the spot of computer room in elementary middle high school. The investigation was carried out side by side for floor, outlet, panel board, earth leakage circuit breaker at computer room In order to assess electrical safety at computer room, grounding simulator and power quality monitor have been used. Potential rise has been measured and analyzed for ground rod and grounding grid by using the simulator. Phase and neutral-line current have been monitored in real time. As a consequence, it is desirable for us to install conductive tile at floor of computer room Grounding grid had better than ground rod for electrical safety. Neutral-line current was produced by unbalanced phase current.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 E
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• pp.1589-1591
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• 1998

This paper presents experimental results of transient impedance characteristics investigated on the site of a large-scale grounding system using impulse current. The ground potential rise was measured while injecting an impulse current and the transient impedance was determined. As a results, the transient impedance was significantly greater than the stationary grounding resistance due to high inductance of ground conductors and leads.

• 조명전기설비학회논문지
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• 제26권3호
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• pp.53-60
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• 2012

The fall-of-potential method is commonly used in measuring the ground resistance of large-scaled grounding system and the current and potential auxiliary electrodes are horizontally arranged. Because the distances between the ground grid to be tested and auxiliary electrodes are limited in downtown areas, it is very difficult to measure accurately the ground resistance of large-scaled grounding system. In this paper, the fall-of-potential method of measuring the ground resistance with the vertically-placed current and potential auxiliary electrodes was examined and discussed. The validity and good accuracy of the proposed method of measuring the ground resistance were confirmed through various simulations and actual tests carried out in uniform and two-layer soil structures.

• 전기학회논문지
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• 제62권9호
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• pp.1308-1312
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• 2013

In this paper, carried out for optimal ground system for ensuring safety for electricity used to power equipment in the 20 kHz frequency. Now the grounding system of the mesh electrode, electrode rods are installed for power plant safety and protection against electric shock. However, the electrical equipment grounding system in the 20 kHz were considering the increasing grounding impedance due to the high frequency and the magnetic shielding. But until now, there has been little research on the grounding system. To solve this problem, In this paper was proposed optimal grounding system due to the experiment using a mesh electrode, rod electrode, aluminum plate electrodes. Measurement results, grounding resistance was depending on the material of the electrode grounding resistance. In addition, the leakage current (induced) appeared to be affected depending on the type of electrode.

• 조명전기설비학회논문지
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• 제22권10호
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• pp.62-68
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• 2008

본 논문은 임펄스전류의 인가위치에 따른 심매설 봉상 접지전극의 과도접지임피던스와 규약접지임피던스 특성에 관하여 기술하였다. 과도접지임피던스는 심매설 접지전극의 길이 및 임펄스전류의 상승시간과 인가위치에 강하게 의존하며, 접지전극의 자체 인덕턴스는 짧은 시간 영역에서 점지시스템의 과도접지임피던스에 크게 영향을 미치는 것으로 나타났다. 심매설 봉상 접지전극의 자체 인덕턴스의 저감은 과도접지임피던스 특성의 개선에 결정적인 역할을 한다. 접지도선의 길이는 최대한 짧게 하여 접지전극의 상단에 접속하는 것이 효과적이다.

• 조명전기설비학회논문지
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• 제25권6호
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• pp.68-74
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• 2011

The touch or step voltages which exist in the vicinity of a grounding electrode are closely related to the earth structure and resistivity and the ground current. The grounding design approach is required to determine the grounding electrode location where the hazardous voltages are minimized. In this paper, in order to propose a method of mitigating the electric shock hazards caused by the ground surface potential rise in the vicinity of a counterpoise, the hazards relevant to touch voltage were evaluated as a function of the soil resistivity ratio $\rho_2/\rho_1$ for several practical values of two-layer earth structures. The touch voltage and current on the ground surface just above the test electrode are calculated with CDEGS program. As a consequence, it was found that burying a grounding electrode in the soil with low resistivity is effective to reduce the electric shock hazards. In the case that the bottom layer soil where a counterpoise is buried has lower resistivity than the upper layer soil, when the upper layer soil resistivity is increased, the surface potential is slightly raised, but the current through the human body is reduced with increasing the upper layer soil resistivity because of the greater contact resistance between the earth surface and the feet. The electric shock hazard in the vicinity of grounding electrodes is closely related to soil structure and resistivity and are reduced with increasing the ration of the upper layer resistivity to the bottom layer resistivity in two-layer soil.

• 조명전기설비학회논문지
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• 제22권2호
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• pp.57-62
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• 2008

본 논문에서는 전위상승에 대한 개별 접지전극과 연접된 접지전극의 비교를 다루었으며, 시험전류가 접지전극에 흐를 때 실시간으로 접지방식에 대한 전위상승이 측정 및 분석되었다. 접지시스템의 전위상승을 분석하기 위해 반구형 수조실험장치가 사용되었고, 이를 이용하여 접지방식 및 거리에 따라 전위상승이 측정되었다. 실험장치는 반구형 수조, 전원공급장치, 이송형 전위계측장치, 시험 접지전극으로 구성되었고 전위계측장치의 프로브가 수평방향으로 이송함에 따라 전위상승이 측정되었고, 접지전극으로는 80 : 1 축척의 봉형 접지전극을 사용하였다. 개별 접지전극의 전위상승이 연접된 접지전극보다 높게 나타났으며 전위분포는 접지전극으로부터의 거리에 의존하는 특성을 나타내었다.