Lightning performance of grounding systems of overhead lines

This paper presents a synthesis of the major aspects involved in the response of electrodes subjected to lightning currents and discusses their influence on the lightning performance of overhead transmission lines in terms of backflashover occurrence. Most of the results and analyses presented herein were derived from recent works and contributions developed by the authors´ research group related to the lightning performance of transmission lines. This work focuses on the behaviour of long counterpoise wires subjected to realistic representations of first and subsequent strokes. Results in terms of grounding potential rise, grounding impedance and overvoltage across insulator strings are discussed.