Transient behaviour of grounding electrodes in uniform and in vertically stratified soil using state space representation

This investigation is devoted to study, in time domain, the transient behaviour of vertical and horizontal grounding conductors submitted to impulse current using state space representation-based transmission line method. This study has been carried out with and without incorporating soil ionisation and mutual coupling between conductor elements for soils of low and high resistivities. The results are focused on the time-domain solution of the electrode's transient potential rise and its impulse performance parameters. The results show the importance of including the mutual coupling between segments of the same electrode and soil ionisation. The results are compared with both published theoretical approaches and experimental measurements, and show acceptable agreement. This method has been applied to compute the transient potential of horizontal electrodes buried in vertically stratified soil, a situation which can occur where long horizontal counterpoise is buried in a highly contrasting soil along its length.