• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.57-60
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• 2008

A design criterion of grounding systems is commonly based on low frequency resistance in Korea. When lightning surges which have high frequency components are injected into the grounding system, the grounding impedance is greatly different from the static grounding resistance. This paper presents the grounding adimittance and phase on the frequency range from 100 [Hz] to 15 [MHz] using water tank simulating the grounding system in different water resistivities. As a result, capacitive effect is dominant over the frequency of 100 [kHz] at the water resistivity of 1,000 [$\Omega$ m]. On the other hand, the inductive characteristics appear at the low water resistivity. Consequently, dependence of grounding impedances on the frequency of injected current is strongly related to resistivity.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.8
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• pp.109-115
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• 2008

A design criterion of grounding systems is commonly based on the ground resistance measured with low frequency in Korea. When lightning surges which have high frequency components are injected into the grounding system, the grounding impedance is great]y different from the static grounding resistance. In order to investigate the effect of water resistivity on the high frequency performance of grounding systems, this paper presents the frequency-dependent admittance using water tank simulating the grounding system in different water resistivities. As a result, because of capacitive effect admittances and conductance are increased with increasing frequency in higher water resistivity of greater than 500[${\Omega}{\cdot}m$]. On the other hand, admittances and conductances are decreased with increasing frequency due to inductive effect in lower water resistivity of less than 500[${\Omega}{\cdot}m$]. The phase difference between the current and voltage increases in the range of 200[kHz] to 5[MHz]. Consequently, frequency-dependent performance of grounding systems is closely related to the soil resistivity, it is necessary to consider the effect of grounding system performance on the frequency and soil resistivity.