The Transient Performance of Power Line Towers

Abstract

This paper presents a refined approach to the transient analysis of power line towers. Each section of the tower’s steel structure is accurately modeled as a non-uniform transmission line.  Among other features, an efficient representation of the towers’ cross-arms as open-ended non-uniform lines and their subsequent approximation by lumped capacitors will be explored. Furthermore, the error introduced by neglecting the presence of the cross-arms, as well as the effect of their number (three or six) will be the subjects of  detailed investigations. Based on the suggested tower model, the paper will then present the results of a comprehensive parameter study addressing the effect of the tower footing resistance on its response to lightning surges. It is believed that the results can lead to useful guidelines to the proper selection of this resistance.

Index Terms: electromagnetic analysis, frequency domain analysis, frequency response, lightning, power transmission, transient response.