This parer presents the soil ionization phenomena and parameters associated to characterize the transient performances of grounding system under lightning impulse Currents. Ionization properties in occurring some soil media were experimentally investigated. The cylindrical test cell was employed in order to facilitate the analysis of soil breakdown field intensity and ionized radius. The soil breakdown field intensity, dependence of impedance on the amplitude of impulse current, V-I curves and transient impedances were discussed based on the voltage and current oscillograms. It was found that the ionization process and dynamic behaviors were strongly dependent on the types of soil and two current peaks were not observed in highly water-saturated soils. The results presented in this paper will provide useful information on the improvement of transient performance of a grounding system subjected to lightning impulse Current considering the soil ionization.
[1]
A. Bonamy,et al.
Electrical parameters associated with discharges in resistive soils
,
2004,
IEEE Transactions on Power Delivery.
[2]
N.M. Nor,et al.
Characterization of ionization phenomena in soils under fast impulses
,
2006,
IEEE Transactions on Power Delivery.
[3]
H. Griffiths,et al.
Determination of threshold electric field E/sub C/ of soil under high impulse currents
,
2005,
IEEE Transactions on Power Delivery.
[4]
A. M. Mousa.
The soil ionization gradient associated with discharge of high currents into concentrated electrodes
,
1994
.
[5]
S. Sekioka,et al.
Current-dependent grounding resistance model based on energy balance of soil ionization
,
2006,
IEEE Transactions on Power Delivery.
[6]
P. Chowdhuri.
Impulse impedance tests on laboratory model ground electrodes
,
2003
.