Assessment of relative importance of tower and ground models in insulation co-ordination studies.

摘要

Accurate knowledge of the surge response of the transmission lightning-induced voltage magnitude and waveforms across the insulator strings in EHV Transmission lines is important in order to develop adequately protected transmission systems.; The main factors affecting this voltage are the tower and ground characteristics and their modelling. The aim of this thesis is to compare, by using PSCAD as a simulation tool, the effectiveness of different tower and ground models available in literature. The simulations have been applied to actual EHV tower geometries for which field gathered experimental data is available. Based on a comparison of simulated and experimental results a tower model which best mirrors experimental data has been selected and used to examine the effect of ground resistance. Furthermore a detailed ground model has also been considered. By combining the two models, the relative importance of tower and ground models in the calculation of lightning-induced voltage has been assessed.