Impulse response and electric field computation of various rod electrodes

Abstract

Ionisation process has been known to occur in soil, when earth electrodes are subjected under high impulse conditions. In this paper, experimental results on impulse response of various earth electrodes, namely a conventional copper rod electrode, and three steel rods which had been in a form of solid, hollow and hollow with stamping of star shaped, is presented. Impulse tests were performed for a range of voltage magnitudes up to 300 kV. Computation of electric field is carried out with Finite Element Method (FEM) to obtain its profile, and determine the electric field values produced for each rod electrodes and peak currents. Experimental results show that little difference in its impulse resistance with increasing current magnitudes in these electrodes, which could be due to the critical electric value, Ec of the soil, and electric field of the rod electrode, which balances up its ionisation levels.