Lightning Surge Response Of Transmission Towers

A sensitivity study of HV and EHV lightning performance shows that surge response characteristics of towers and lines are as important as the footing response. Tower travel time has a very large sensitivity for taller double-circuit lines. Existing methods for analysis of tower and line response have considerable uncertainty. This uncertainty is resolved by extensions to travelling- wave analysis combined with experimental verification. New equations for tower surge impedance and tower travel time are proposed to deal with the most common situation of a midspan stroke to the skywire.