Voltages Induced in Single-Phase Overhead Lines by First and Subsequent Negative Lightning Strokes: Influence of the Periodically Grounded Neutral Conductor and the Ground Resistivity

The influence of a periodically grounded neutral conductor on voltages induced by first and subsequent negative strokes in single-phase overhead lines for different ground resistivity values is investigated by means of computational simulations using the hybrid electromagnetic model. Configurations of medium- and low-voltage networks were assumed. Currents of first and subsequent strokes with median parameters obtained from the measurements of Mount San Salvatore and Morro do Cachimbo stations were adopted. While the simulation of subsequent stroke considered the current departing from the ground, the first-stroke simulation considered 100-m-height attachment of the upward and downward leaders. For the conditions simulated herein, the results indicated the largest induced-voltage amplitudes for first-stroke events.