A New Concept in the Design and Implementation of the Grounding Transmission Lines

Abstract

Lightning overvoltage cause the majority of outages in electrical transmission lines, mainly through a back flashover in the transmission system insulation. Key factors in reducing the number of back flashovers are: selection of route in design power lines, grounding, and increase of withstand insulation voltage and installation of metal oxide surge arresters along the transmission line. Reduction of grounding impedance is one of the most efficient ways to prevent the occurrence of back flashovers. The main issues with grounding in Bosnia and Herzegovina and the region are the wide range of specific resistivity in different soil types (10–10,000 Ωm), relatively high isokeraunic levels and high voltage lightning currents (in excess of 150 kA). The paper outlines the main features of own experimental research for reducing back flashovers by lightning current.