| Title |
Characteristic Analysis of Transient Impedances of Small-sized Ground Electrodes in a Ionization Region of Soil |
| Authors |
Yang-Woo Yoo ; Ju-Hong Eom ; Sung-Cheol Cho ; Tae-Hyung Lee ; Bok-Hee Lee |
| Keywords |
Ionization in soil ; Transient impedance ; Threshold electric field ; Ground electrode |
| Abstract |
This paper presents measurement results of transient impedance for small-sized ground electrodes in a discharge region of soil. For a realistic analysis of ionization characteristics near the ground electrode, three types of ground rod installed outdoors and high voltage impulse generator were used for injecting test current. From the analysis of response voltage and current flowing ground electrode to earth, it is verified that the ionization near the ground electrode contributes to reduction of ground impedance and limits the ground potential rise effectively in high resistivity soil. As a threshold electric field density for ionization is small in low resistivity soil, the shape of ground electrode rarely contributes to the transient impedance. And, from the experiment result with shape of ground electrode, the rod with needles is more effective to reduce the transient impedance than the plate electrode in the voltage range including with ionization regions of soil. |