Enhanced prediction of electric field distribution in lightning protection systems with heterogeneous ground

This research investigates the effect of geological discontinuities on the electric breakdown distributions near vertical and horizontal lightning conductors (VLC and HLC) in various ground conditions. To investigate this effect, numerical simulations were carried out using COMSOL Multiphysics. The simulations took into consideration detailed models of the lightning conductor geometries, ground structures, and parameters of the lightning conductor for varying ratios of horizontal distance to conductor height (D/hc, where D = horizontal distance between the lightning conductor and ground discontinuity interface, and hc = height of the lightning conductor above ground level). Results show that for D/hc = 1.5, the electric field strength near the lightning conductor and discontinuity interface is 20% lower than that obtained from the homogeneous model without this conductor. On the other hand, for D/hc ≥ 3.5, the electric breakdown strength agrees well with the conductor less model, indicating negligible impact on discharge attraction. The equipotential lines and field intensities around the interface have shown non-uniform distributions. Results have brought forth important practical implications in developing an efficient lightning protection system over different types of earth.