Numerical electromagnetic analysis of lightning-induced voltage over ground of finite conductivity

Numerical Electromagnetics Code (NEC-2), which is a computer code to analyze the three-dimensional electromagnetic (EM) field around thin wires in the frequency domain, has been successfully used in lightning-related studies such as lightning surge analyses or lightning EM pulse calculations over a perfectly conducting ground. NEC-2 is still more useful in investigating lightning-induced effects over ground of finite conductivity. This application of NEC-2 is investigated by comparing calculated results with an experiment over lossy ground. The advantages of the analysis using NEC-2 are that it can accurately compute the current distribution along a wire structure with small amount of postulation. It automatically incorporates coupling between a lightning channel and transmission lines, and it can also take account of finitely conducting ground in transient condition. In addition, it can also model conductors in any arbitrary angles, and it is available in the public domain.