Direct Lightning of a Compact Overhead Distribution Line with Covered Conductors and Periodic Grounding

Covered conductors are adopted for medium and high voltage overhead lines to limit the line right-of-way and the occurrence of faults to ground caused by external agents. The insulating layer of the phase aerial cables allows to diminish maintenance pruning in rural or remote areas and increase the resilience of these compact lines with respect to extreme weather events. This paper assesses the modeling of the line and the analysis of the results related to direct lightning of the messenger wire, i.e., the upper bare conductor installed for mechanical support. Indeed, in case of direct lightning, the messenger wire may act as an unintentional shield wire. Travelling voltages due to direct lightning of a compact distribution line are calculated, while investigating also the insulation withstand capability.