Dryvetskyi S. Protection of power lines with protected wires from lightning induced surge

The dissertation is devoted to solving the actual scientific and applied problem in the field of lightning protection of transmission lines with protected wires of middle classes of voltage from the lightning suppressors supplied by lightning strikes near the electric transmission line. The urgency of the topic of the dissertation paper is as follows. At present, protected wiring for PL is gaining widespread in Ukraine, due to the technical policy of the Ministry of Fuel and Energy. Wires in the protective cover for air lines of 6-35 kV were designed to increase the reliability of distribution and transmission of electricity. The use of wires in a protective shell has several significant advantages, namely: reliability, economic feasibility. With obvious advantages, there is a deficiency that is determined by the need to protect the submarine from lightning surges. The concept of lightning protection is so versatile that the methods of choosing suitable protection from threats are different in different regions. The factors that determine the method of protection are the thunder activity and its intensity in each particular region. An analysis of the operation experience of distribution electrical networks shows that their reliability is lower than in the networks of higher voltage classes. Damage in distribution networks causes most of the damage associated with interruptions in consumer electricity supply. One of the main causes of accidents and violations is the storm surges on the air lines (PL), causing impulse overlays and the destruction of insulators and lead to arc closures, with associated equipment damage, trips of lines. Emergency trips of 6-35 kV overhead transmission lines due to lightning surges make up 40% of the total number of trips. Due to low impulse strength, the isolation of distribution networks is subject to overheating both from overvoltages in direct lightning bursts, and from inductive surges when lightning is near the line. The latter are the main cause of the thunderstorms and damage to the equipment of networks 6-35 kV, amounting in some cases up to 90%, and when passing the route of the submarine in the forest area and up to 100% of their total. Thus, the reliability of electricity supply to consumers largely depends on the effectiveness of lightning protection measures.