| Title |
Transient Potential Rises of Grounding Grid Response to Lightning Currents |
| Authors |
Dong-Sung Kim ; Feng Li ; Bok-Hee Lee |
| DOI |
http://doi.org/10.5207/JIEIE.2021.35.5.048 |
| Keywords |
CDEGS Program; Earth Resistivity; Grounding Grid; Lightning Current; Transient Potential Rise |
| Abstract |
A type method of evaluating the performance of grounding electrodes for lightning protection system is to analyze transient potential rises of the grounding electrode by flowing lightning currents. Recently, many studies related to potential rises of grounding electrode systems have been carried out, but more detailed and in-depth studies under various design parameters are required. This paper aims to analyze the transient potential rises response to lightning currents entering into grounding electrodes. The transient potential rises due to the lightning currents injected into the grounding grid with 4 mesh 10m10m size according to the incident location as a parameter of the earth resistivity is simulated by using CDEGS program. As a result, the potential rise of grounding grid was different depending on the wave front time and incident point of lightning currents, and the soil resistivity where the grounding grid is buried. The potential rises of grounding grid conductors was highest when the lightning current was injected at a corner of the grounding grid, but on the other hand it is relatively low by injecting the lightning current at the center of grounding grid. Also when 0.25/100㎲ impulse current corresponding to the subsequent negative stroke lightning current was injected, the potential rise was maximum value. The lower the earth resistivity where the grounding gird was buried, the lower the potential rise of grounding grid was. It was confirmed that the potential rise of grounding grid buried in a place with low earth resistivity was dominantly influenced by the wave front time and the incident location of lightning currents. |