OVERHEAD LINE TOWER MODEL IN TASKS OF LIGHTNING PROTECTION

Energetics. Electrical engineering
Authors:
Gulov Aleksandr M. Kolychev Aleksandr V.
Abstract:

A lightning strike at the top of the tower results in dangerous overvoltages, which can lead to back flashover from the tower to the phase wire. Back flashovers are one of the reasons for the transmission line outage. Therefore, various models of overhead line tower have been developed and continue to be developed to analyze transient processes in the tower during lightning overvoltages. Several tower models were compared to calculate the lightning protection of a double-circuit 110 kV overhead line. In Russia, the most common tower model is a set of inductances, while foreign countries employ tower models from surge impedances: the article compares both models. Curves of critical lightning current for several types of tower models are calculated for 110 kV overhead line in EMTP-ATP. The tower footing resistance varies to study the effect of voltage drop at the tower.