• 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.21 no.4
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• pp.73-79
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• 2007

In order to analyze the potential rise of grounding systems installed in buildings, a hemispherical grounding simulation system was studied. Potential rise was measured and analyzed regarding the shape and distance of the grounding electrodes by using this system. The system was composed of a hemispherical water tank, AC power supply, a movable potentiometer, and test grounding electrodes. The potential rise was measured in real time by the horizontal moving probe of be potentiometer. The test grounding electrodes were fabricated through reducing the grounding electrode installed in real buildings such as the ground rod, grounding grid and so on. The potential rise was displayed in a two-dimensional profile and was analyzed regarding the shapes of the ground electrodes. The potential rise of the grounding grid combined with a ground rod was the lowest of every grounding electrode tested. The proposed results can be applicable to evaluating ground potential rise in grounding systems, and the analytical data can be used to stabilize the electrical installations and prevent electrical disasters.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.3
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• pp.39-45
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• 2010

This paper deals with investigation on the spot for grounding systems of buildings based on international standards at construction sites. The investigation was carried out for grounding method, grounding type, shape of grounding electrode, grounding for a lightning protection system, continuity of steelwork in reinforced concrete structures, etc. The investigation on the spot was performed by a researcher and engineer with over fifteen years of industry experience all over the country. As a result of the investigation on the spot in 13 buildings, common grounding and structure grounding methods were dominant. The safety improvement methods include installation of equipotential bonding conductors for the connection to the main earthing terminal, equipotential bonding conductors for supplementary bonding, use of Surge Protective Devices (SPD), and safe connections between earthing conductors and the rebar.

• Proceedings of the KIEE Conference
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• summer
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• pp.509-511
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• 2004

Grounding rods as a discharge path are normally used to ensure the safety of human beings and facilities from the over-voltages and the over·current. Each grounding mode class 1, class 2, class 3, special class 4- has prescribed ground resistance values which are kept by the utilities. However, in the distribution system, it is very difficult for grounding rods to obtain the prescribed ground resistance values because of the limits of installation space. Therefore, in this paper, the grounding effects of the grounding copper bands which are recently developed to use efficiently in small area and the grounding rods are compared by testing the ground resistance values, ground potential rise(GPR), and step voltage in various cases.

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.482-484
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• 2001

Earth resistivity and changing of grounding electrode's shape are very important factor to reduce grounding resistance. Earth resistivity has different values according to property of soil and is effected by temperature, climate, and environment. This Paper describes the effect of the grounding resistance according to the grounding type such as driven rod, counterpoise grounding and mesh grounding. And also grounding resistance values with earth resistivity and shape of grounding electrode were represented in this paper.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.69-72
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• 2008

This paper presents the transient and conventional grounding impedance behaviors of large grid grounding system associated with the injection point of impulse current The measurement methods consider two possible errors in the grounding-system impedances: (1) ground mutual resistance due to current flow through ground from the ground electrode to be measured to the current auxiliary, (2) ac mutual coupling between the current test lead and the potential test lead The test circuit was set to reduce the error factors. The transient grounding impedance depends on the rise time and injection point of impulse current It is effective that grounding conductor is connected to the center of the large grid grounding system.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1948-1949
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• 2007

This paper presents the characteristics and effects of grounding resistor and impedance. In grounding system, Grounding resistor is governed neutral currents and voltage. It seems that, grounding resistor has 0 value, then circuit has no faults. While if grounding resistor has large value, then neutral current has large value of fault current and it is made a damage to the utility. In order to analyze the grounding impedance characteristic, EMTP simulation has been used. The grounding impedance characteristic has been analyzed and tested for various grounding arrangements and electrode circuit shapes.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.4
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• pp.29-36
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• 2006

This paper deals with the potential interferences between grounding electrodes in various grounding electrodes. The ground potential rise and potential interference coefficients were measured by using and electrolytic tank and calculated by CDEGS program as functions of the configuration and size of grounding electrodes and the distance between grounding electrodes. The ground potential rise and potential interference coefficient strongly depend on the distance between grounding electrodes, the shape and size of grounding electrodes. The potential rise interferences between grounding grid and grounding grid is lower than those between grounding grid and ground rod.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1459-1467
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• 2011

This paper proposes the effective method to improve the protection from induced lightning Surge by making common grounding from individual grounding. Common grounding under equipotential principle is more effective than individual grounding for lightning Surge protection, and so common grounding is indicated as international technical standard under the AC power supply system with neutral line. So, this paper is to propose the effective way of induced lightning Surge protection method for currently installed power supply system which has no neutral grounded line and individual grounding which are weak for lightning Surge protection. This proposal can improve the power supply system as has neutral line, and improve the grounding system to common grounding system. And also this paper proposes to make effective equipotential system with voltage variable shunting devices for lightning Surge protection.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.215-218
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• 2013

This paper proposes the effective method to improve the protection from induced lightning surge by making common grounding from individual grounding. Common grounding under equipotential principle is more effective than individual grounding for lightning surge protection, and so common grounding is indicated as international technical standard under the AC power supply system with neutral line. So, this paper is to propose the effective way of induced lightning surge protection method for currently installed power supply system which has no neutral grounded line and individual grounding which are weak for lightning surge protection. This proposal can improve the power supply system as has neutral line, and improve the grounding system to common grounding system. And also this paper proposes to make effective equipotential system with voltage variable shunting devices for lightning surge protection.