Computation of Lightning Voltage Surges on Tall and Conventional Transmission Towers
Transmission tower modelling is very important to assess the electromagnetic transient caused by lightning strikes in power systems. In this context, conventional tower models are very well studied in the literature. However, there are few studies on tall transmission towers which have been receiving great attention recently due to their own characteristics. Tall transmission towers are built on river crossings and/or over dense forest canopy to reduce environmental impact in these areas. In this paper, the voltage surge caused by an incidentlightning at the top of the conventional and tall towers are determined. For both structures, a lumped electric circuit approximated by Vector Fitting technique is proposed which takes into account the tower-footing grounding system buried in dierent homogeneous soils. The results show a clear dierence in the time domain voltage response for the conventional and tall transmission towers which is more pronounced as the soil resistivity increases and/or the tower becomes taller.