On the High Frequency Performance of Vertical Ground Electrodes and LRM Application

This article addresses the critical need to reduce grounding impedance for the protection of both individuals and electrical equipment under normal and faulty conditions. While numerous techniques exist for low-frequency applications, challenges arise at higher frequencies due to the inductive behavior inherent in grounding systems. The efficacy of low resistivity material as a solution to decrease grounding impedance at high frequencies is investigated. Through experimental studies using vertical ground electrodes with varied lengths and some backfilled with a commercial conductive aggregate compound, grounding impedance is analyzed across the frequency range between 10 Hz and 10 MHz. A considerable reduction in grounding impedance is achieved. Based on these findings and other published results, practical insights for designing effective grounding systems are derived, where alternative arrangements are proposed, exhibiting promising results for further enhancing high-frequency performance.