Numerical electromagnetic analysis of lightning protection system over lossy ground

The electromagnetic transients of lightning protection system(LPS) under direct lightning strike is studied using NEC2. By employing antenna return-stroke model, lightning channel's inducing effect and finite conductivity of ground are all taken into account. Results show that the lightning channel's inducing effect tends to decrease the current flowing through horizontal conductors, and increases the current flowing through vertical conductors near the striking point. The results obtained under perfect ground assumption have a good agreement with the published experimental results. The simulation also predicts that the finite conductivity of the ground affects the branch current significantly, it increase the LPS's current dissipating efficiency, the higher the soil resistivity, the more uniform the current flowing in vertical conductors.