Impulse Impedance of the Horizontal Grounding Electrode: Experimental Analysis versus Full-wave Computational Model

The paper deals with the comparison of novel experimental and computational method for obtaining the impulse impedance of the horizontal grounding electrode defined as a ratio of maximum values of induced voltage and current at the injection point on the electrode. Impedance is obtained in-situ based on injection of the 1.5 A current pulses (4/10 mu s and 8/20 mu s) and measurement of corresponding voltage drop. On the other hand, the current distribution along the electrode is calculated using the antenna theory based model featuring the thin-wire approximation and corresponding Pocklington integro-differential equation in the frequency domain. The equation is solved using analytical technique. The results obtained via different methods agree satisfactorily, thus validating antenna model of the grounding electrode. Obtained results are applicable for any grounding system based on horizontal grounding electrode.