ABSTRACT
Quantitative evaluation is carried out in this chapter for the effect of lightning surges on the surface impedances of power system installations such as transmission lines, transformers, line towers, etc. Since time duration up to the peak of lightning surge front is on the order of 1 s and for most of the surge tail it is on the order of 100 s, an increase in the characteristic impedances for transmission lines and transformers (even the ungrounded) is confined to only a very short time, about 100 s. Consequently, analysis regarding the concept of skin effect is substituted by examination for the behavior of the surface impedances across the frequency spectrum as reliable basis for skin effects calculations.
