A Computational Improvement in Grounding Systems Transient Analysis

This study investigates the adequacy of a modification in the evaluation of transversal and longitudinal impedance matrices for wideband modeling of grounding electrodes without a significant loss of accuracy. It is based on an approximation of the so-called hybrid electromagnetic model (HEM) and is called modified-HEM (MHEM). It exploits the average distance between segmented electrodes, allowing to pre-calculate the integral prior to the evaluation of the frequency loop improving considerably its numerical performance. Apart from some discrepancies for frequencies above a few MHz, the results for the harmonic impedance presented a very good accuracy when compared with the ones obtained using HEM. A comparison with an experimental test is carried out to enforce the adequacy of the investigated formulation within suitable parameters.