Calculation of 10 kV overhead transmission lines failures caused by induced overvoltages

10 kV overhead transmission lines (OTL) are the main element in distribution circuits. Power supply reliability directly depends on the line reliability. However, the OTL are most influenced by external forces, especially lightning (approximately half of all failures). Thus, improving OTL resistivity to lightning is a problem that needs solving. The aim of the work is to determine the specific annual quantity failures of 10 kV OTL caused by lightning induced overvoltages (IO) taking into account the electrical strength of insulation. Pulse electrical strength tests were performed on insulators.