Numerical electromagnetic field analysis of lightning current intall structures

摘要

The Numerical Electromagnetic Code (NEC-2) is applied to thenelectromagnetic analysis of tall structures hit by lightning. Thenadvantage of the analysis using NEC-2 is that it can accurately computenthe current distribution along a conductor system by the method ofnmoments. The waveforms of the lightning currents measured onnfreestanding tall structures are well reproduced, and the computednwaveforms of the electric and the magnetic fields at some distance fromnthe structure hit by lightning agree fairly well with the measurednwaveforms. In the analysis, a lightning channel is represented by anvertical conductor that is loaded by series inductance and resistance sonas to simulate the slow propagation velocity of a current wave on thenlossy channel. This representation is demonstrated to be quite effective