Transient voltage response of ground electrodes in the time-domain

This paper proposes an alternative and simple methodology to find the transient voltage response of a ground electrode in the time-domain. The methodology uses a parametric modeling approach to obtain a model, in terms of a polynomial ratio, to represent the ground electrode impedance in the frequency-domain. Once this model is obtained, it is used to derive a time domain step response for the electrode impedance, which is further used in the procedure to derive the desired transient voltage response. The proposed approach deals with single wire ground electrodes and also with the typical arrangements used in transmission lines grounding towers, with several coupled electrodes. Comparisons with other methodology and with measured results are presented. An application example is used to demonstrate the proposed methodology usefulness.