• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.347-350
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• 2009

The latticed mesh grounding is compared with the diagonal mesh grounding. In the result, The latticed mesh grounding better than the diagonal mesh grounding at the maximum touch voltage, the grounding resistance and the total length of conductors.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.84-87
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• 2009

In this paper, the grounding area of the latticed mesh grounding in the original spare is compared whith diagonal one. the $E_M$, $R_g$ and $L_M$ of the diagonal mesh grounding were more decreased than latticed ones. The principles that, the diagonal mesh grounding elements, and compared with the simulation results also the reduction principle are explained in this paper.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.60-66
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• 2010

Mesh grounding electrodes in Korea and abroad are designed as lattice-shaped equidistance grounding grids. In case of a lattice-shaped grounding Grid, however, there is a problem of higher touch voltage at the corner of the grid relative to the center. To overcome this problem, we used oblique-shaped equidistance grounding grid to reduce the area of the corner where mesh voltage occurs. As a result the mesh voltage was reduced. Therefore, this paper suggests the use of oblique-shaped grounding grid instead of the existing lattice-shaped ones. It applied the same grounding design dimensions for both lattice-shaped and oblique-shaped grounding grids, compared and analyzed mesh voltage, GPR, ground resistance, total length of grounding conductor, verified that oblique-shaped grounding grid is superior to the lattice-shaped.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.2
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• pp.63-68
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• 2005

This paper describes the characteristics of effective impulse ground impedance of deeply driven ground rods combined with grounding grid or counterpoises with needles. The potential rises of the test ground electrodes were measured as a function of the rise time of applied impulse currents and the effective impulse ground impedances were calculated The impulse ground impedances of deeply driven ground rods strongly depend on the rise time of impulse currents and significantly reduced by the connection of grounding grids in parallel.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.3
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• pp.28-35
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• 2006

Recently, a number of equipments related with electricity, electronics, and communication in the same building are needed to the grounding system for safety from unexpected accidents. When the faulted electric current flows into a certain grounding system, the potential rise in that system takes place and it might induce the potential rise to other grounding system. This potential interference was strongly affected by the surface potential, which was deeply related with the electrode shape. In this paper, the fundamental formula was deduced on the basis of surface potential of two grounding electrodes. Which corresponds to source of the potential interference and other grounding electrode, respectively. Therefore, the degree of potential interference in this mesh grounding electrode system was verified by the simple model simulation. In addition, in order to identify the difference between the grounding resistance in the realistic construction site and the expected value from the corresponding simulation, the experiment was performed with model on a reduced scale about the realistic grounding system. It consists of stainless steel hemisphere electrodes in a water tank. From this work, the grounding resistance in the mesh grounding electrode showed the good coincidence results between those. Consequently, it is confirmed that the grounding resistance in the mesh electrode is possible to be estimated by performing the experiment using the water tank model.

• Journal of Advanced Navigation Technology
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• v.19 no.3
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• pp.230-236
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• 2015

In this paper, the electric potential of electrode surface is investigated by assuming them as two dimensional sets of point current sources. And, the simulated water tank is manufactured as a reduced scale of the earth. Henceforth, the adequate model electrode for test is decided to decrease experimental errors relevant to the limitation of the size of the water tank. The one of important things of this work, the deduction method of the potential interference factor is proposed, which used as the criterion of the potential interference according to the shape of conductors and the laying conditions, when multiple grounding conductors are situated at the same resistance grounding area. Also, the validity of this theory is verified from a numerical simulation of the grounding electrode to be used in experiments, and this study is realized by the verified theory and the simulated experiments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.4
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• pp.724-730
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• 2006

The earth resistance is a essential basic factor of the performance of the earth. The earth enables system to be operated in a stable way not only against thunderbolts, unexpected transitional currents, the inflow of voltages and electric noises but also protect human life from electric shocks. In a domestic case, there is a technique criterion about earth technique but it falls short of reality since the content is very limitted, which causes a lot of problems to establish communications facilities. This paper gives the results through actual measurement or the earth resistance as reffered date in a way to improve these problems.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.10
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• pp.68-73
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• 2006

As in the measurement of ground resistance by using the 3 point fall-of-potential method, it is known that the distance of current electrode should be at the point of showing the plateu on the potential curve. But the problem is that it my be practically impossible to meet the condition in actual sites. For solving such a situation, this paper provides the least distance of current electrode according to the analysis for the test-field measurement showing that it is feasible to measure the ground resistance in the two in current electrode distance as the length of driven-rod type electrode and the some district length of mesh electrode.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1418_1419
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• 2009

This paper presents the transient impedance when high current impulse up to 5 kA is applied to a scaled grounding grid in test field. For a realistic analysis of transient impedance on the high current impulse in the ground systems, grounding electrode installed outdoors and impulse current generator was used. The results were discussed based on its voltage and current trace, impulse impedance and V-I curve.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.10
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• pp.1615-1622
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• 2003

Being contacted directly with. ground, the tire tread part is in shape of complex patterns of variable ASDs(anti-skid depth) to satisfy various tire performances. However, owing to the painstaking mesh generation job and the extremely long CPU-time, conventional 3-D tire analyses have been performed by either neglecting tread pattern or modeling circumferential grooves only. As a result, such simplified analysis models lead to considerably poor numerical expectations. This paper addresses the development of a 3-D tire mesh generation considering the detailed tread pattern and shows that the contact pressure and frictional energy distribution of tires considering the detailed pattern become better than those by the simplified tire model.