• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1487_1488
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• 2009

In these days, the common grounding systems are adapted in most large structures. In order to evaluate the performance of grounding system, it is needed to measure ground impedance. Measuring methods of ground impedance for a large scale grounding systems have not been yet presented in detail. In this paper, we analyze earth mutual resistance and mutual coupling of $15{\times}15m$ grounding grid in different arrangements of auxiliary electrode. As a results, the auxiliary electrodes are installed where the error rate due to earth mutual resistance is less than 5%. Also, the potential lead is installed at obtuse angle from the current lead and the overlapped length between potential lead and grounding grid are minimized.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.6
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• pp.50-60
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• 2008

The ANSI/IEEE Std. 80-2000 method has been commonly used to design grounding system for the South Korea domestic market. However, the appropriateness of this method to the ground design environment has not yet been examined. This paper presents a new design grounding system method that complements the ANSI/IEEE Std. 80-2000 method, when the new method is a lied to thickness, dangerous voltage, and grid spaced computations for grounding conductors. Furthermore, this paper examines reliability and economic efficiency issues by comparing of the ANSI/IEEE Std. 80-2000 Annex B's case study with the original method.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2002.11a
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• pp.303-306
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• 2002

This paper presents a novel method for measuring the ground impedance in grounding systems. A square wave current was injected to the main grounding grid through auxiliary electrode, and the test current and ground potential rise(GPR) were measured using the band-pass filter. Ground impedance was calculated from the sinusoidal waveforms of the test current and GPR in frequency range of 20~2100Hz. Also the resistance and reactance component of ground impedance were analyzed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.240-243
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• 2005

This paper presents the transient behaviors of grounding system impedance against lighting impulse currents. The dynamic characteristics of the deeply driven ground rod and grounding grid subjected to the impulse current with various rise time were investigated. It was found that the transient ground impedance strongly depends on the configuration and size of grounding electrodes and the shapes of impulse currents, and the inductance of grounding electrodes has a significant affect on the transient ground impedance of grounding system in the short time domain.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.3
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• pp.120-125
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• 2011

When we design the grounding grid, dangerous voltage ANSI/IEEE Std. 80 method has been commonly used in the domestic area. However, the suitability of the ground rules for the design environment available. However, the suitability of the ground rules for the design environment available. In this paper, sticks according to the electrode conductor in combination with the mesh in order to design the ground by the IEEE Std.80 was designed. So in this paper, we examined of IEEE Std. 80 touch voltage method marginal utility and we induced for those problems by comparison between IEEE Std. 80 touch voltage value and simulation experimentation value. Furthermore, this paper presents a new design grounding system method that complements the IEEE Std. 80 method.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.62 no.3
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• pp.139-144
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• 2013

In Korea, where most of the sites are narrow in space and their earth resistivity is relatively high, the spaces between grounding conductors are likely to be designed narrow in order to lower ground resistance and dangerous voltage below to the permitted safety values. In addition, ground nets are in the shape of square or rectangle depending on the location and size of the facilities and ground contact area, and inner conductors are laid out in grids like the pattern of nets. Nevertheless, with the existing designs, the marginal voltage for safety gets higher as the area is extended further outside, in comparison with that of inner mesh grounding, thus causing much difficulty maintaining them equipotential, and there exist limits in the burial, grounding grid design considering the dangerous voltage of muti-layered model in the constrained sites, was studied.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.261-263
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• 2005

This paper presents the potential interferences between various grounding electrodes. The ground potential rise and potential interference coefficient between grounding grid and ground rod were calculated. The potential rise and potential interference coefficient strongly depend on the distance between grounding electrodes.

• Journal of Magnetics
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• v.22 no.1
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• pp.43-48
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• 2017

In order to detect the current flowing through concealed conductor, this paper proposes a new method based on derivative method. Firstly, this paper analyzes the main peak characteristic of the derivative function of magnetic field generated by a current-carrying conductor, and a relationship between the current flowing through the conductor and the main peak of the derivative function is obtained and applied to calculate the current. Then, the method is applied to detect the conductor current flowing through grounding grids of substations. Finally, the numerical experimental and field experiment verified the feasibility and accuracy of the method, and the computing results show that the method can effectively measure the conductor current of grounding grids with low error, and the error is within 5 %.

• Journal of Electrical Engineering and Technology
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• v.7 no.2
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• pp.225-229
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• 2012

This paper proposes a reduced-scale simulator that can replace numerical analytic methods for the estimation of potential distribution caused by ground faults in various grounding systems. The simulator consists of a hemispherical electrolytic tank, a three-dimensional potential probe, a grounding electrode, and a data acquisition module. The potential distribution is measured using a potentiometer with a position-tracing function when a test current flows to the grounding electrode. Using the simulator, we could clearly analyze the potential distribution for a reduced- scale model by one-eightieth of the buried depth and length of the grounding rod and grounding grid. Once both the shape of the grounding electrode and the fault current are known, the actual potential distribution can be estimated.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.12
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• pp.146-153
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• 2009

Recently, the common grounding systems are adapted in most large structures. Since the ground resistance is insufficient to evaluate the performance of grounding systems, it is needed to measure grounding impedance. Even though the methods of measuring grounding impedance of large grounding systems are presented in IEEE standard 81.2, but they have not been described in detail. In this paper, we present the accurate method of measuring grounding impedance based on the revised fall-of-potential method and measurement errors due to earth mutual resistance and ac mutual coupling depending on locating test electrodes at remote earth were examined for the 15[m]$\times$15[m] grounding grid. As a result, the measurement error due to earth mutual resistance is decreased when the distance to auxiliary electrodes increased. To get rid of measurement errors due to mutual coupling, the potential lead should be installed at a right angle to the current lead. When the angle between the potential and the current leads is an acute angle or an obtuse angle, the mutual couple voltage is positive or negative, respectively. Generally, the measurement errors due to mutual coupling with an obtuse angle route are lower than those with an acute angle route.