| Title |
Make-up of Equivalent Circuit of Grounding System using Water Resistivity in Hemispherical Electrode System |
| Authors |
Bok-Hee Lee ; Jong-Hyuk Choi ; Sung-Bae Bae |
| Keywords |
Grounding System ; Water Resistivity ; Frequency-Dependent Impedance ; Phase Difference ; Adimittance ; Equivalent Circuit |
| Abstract |
A design criterion of grounding systems is commonly based on the ground resistance measured with low frequency in Korea. When lightning grus which have high frequency components are injected into the grounding system, the grounding impedance is greatly different morf 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[Ω·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[Ω·m]. The phase difference between the current and voltage increases in the range of 200[㎑] to 5[㎒]. Consequently, frequency-dependent performance of grounding systems is closely taler to the soil resistivity, it is necessary to consider the effect of grounding system performance on the frequency and soil resistivity. |