| Title |
Frequency-Dependant Grounding Impedances According to the Length of Grounding Electrode and the Joint Position of Ground Conductors |
| Authors |
Jong-Hyuk Choi ; Young-Chul Choi ; Sung-Cheol Cho ; Bok-Hee Lee |
| DOI |
http://dx.doi.org/10.5207/JIEIE.2010.24.5.037 |
| Keywords |
Grounding Impedance ; Soil Resistivity ; Vertical Grounding Electrode ; Counterpoise ; Lightning Surge |
| Abstract |
When lightning surges with wide frequency spectrum and power converting devices are considered, it is desirable to evaluate grounding system performance by grounding impedances. This paper presents the measured results for frequency-dependent grounding impedance for the vertical grounding electrode and counterpoise on a scale of full size. Grounding impedances of vertical grounding electrodes and counterpoises give capacitive or inductive behaviors according to the length of grounding electrodes and soil resistivity. It is inefficient to extend the length of the grounding electrode in order to decrease the ground resistance, and when designing the grounding system, the consideration of the grounding impedance should be desirable. In order to reduce the grounding impedance of counterpoise, the grounding conductors are jointed at the center of counterpoises. It is effective to reduce the grounding impedance by connecting ground rods to counterpoises in parallel. |