Mitigation of Induced Overvoltages in Transmission Lines Using Ground Wires and Surge Arresters

Abstract

This article investigates the indirect effects of lightning on power transmission lines, focusing on induced overvoltages and their impact on system operation. The analysis is performed using the Agrawal coupling model in the time domain, allowing for a precise evaluation of the electromagnetic interaction between lightning-induced fields and overhead conductors. The study considers different line configurations and two types of ground, lossless and lossy, to assess their influence on the amplitude and shape of induced overvoltages. Furthermore, the effectiveness of protection devices, particularly ground wires and surge arresters, is analyzed. The results show that ground wires reduce the incident electromagnetic field strength, while surge arresters effectively limit overvoltages by clipping voltage peaks. Installing surge arresters at both ends of the line provides better protection compared to a configuration with a single set of surge arresters at one end. The results obtained highlight the importance of combining shielding and protection devices to improve the resilience of transmission system to the indirect lightning effects.