Protection from Direct Lightning Strike in the Main Building of the Polytechnic University of Tirana

Abstract

This paper presents a model of analyzing the transient process of dissemination of electromagnetic wave of the lightning protection system, which is placed on the terraces of the Polytechnic University of Tirana. According to this study simulations were conducted by using the well-known ATP-EMTP software. We have calculated the values of voltages and currents and have also analyzed them. The modeling of conducting segments of protective grid is made by line losses with distributed parameters according to Clark’s model. Direct lightning strike to the protection network, is modeled with the Heidler’s type of current source. Analytical expressions for distributed and lumped segment parameters derive from use of the average potential method. The number of the segments required for an accurate simulation depends on the highest frequency of the injected impulse. This paper presents a transmission line model (TLM). Direct lightning strike onto the top of the building of the Polytechnic University of Tirana is considered. By comparing the results obtained by TLM model and those developed by a more exact electromagnetic model, a specific similarity has been observed, both in the computed amplitude of the overvoltage, as well as in the temporal and spatial overvoltage distribution. Due to the limitations of the transmission line model approach and the application of the ATP-EMTP software package, the electromagnetic coupling between segments is not be taken into account. The earth model is limited to the heterogeneous earth. The soil ionization effect can be included.

DOI: 10.5901/ajis.2015.v4n2s2p250