Influence of Direct Lightning Strikes and Lightning Strikes Near Power Lines with Protected and Non-Insulated Wires

Many years of experience in the construction and operation of 6 - 35 kV overhead power lines with bare wires showed insufficient reliability of such lines and their increased danger. One of the main causes of accidents and violations are thunderous overcharging on overhead lines, causing impulse overlap and destruction of insulators and leading to arc closures, with collateral damage to equipment, line outages. Emergency outages of 6 -35 kV overhead lines due to lightning overvoltages account for up to 40% of the total number of their trips. Due to low impulse strength, insulation of distribution networks is subject to overlapping both from over voltages in direct lightning discharges and from induced overvoltages in the case of lightning near the line. The latter are the main cause of thunderstorm outages and damage to the equipment of 6 -35 kV lines, amounting to 90% in some cases, and when the overhead lines highway passes through the forest and up to 100% of their total number. Thus, reliability of power supply to consumers largely depends on the effectiveness of lightning protection measures.