Problems caused by insulated overhead transmission line in medium-voltage system and the prevention methods

Le résumé fourni par la source

In order to enhance the safe operation of medium-voltage distribution system, insulated coating is used to cover the transmission line. However, some problems are activated by the insulated overhead transmission line. Lightning-caused breakage of transmission line and lightning overvoltage are two problems that remain unclear. In this paper, the generation, development and evolution of lightning-caused breakage of transmission line are analyzed. Five stages, which are formation of pinhole in the insulated coating, lightning induced flashover, establishment of power frequency arc, continuous arc at the pinhole, and arc burning induced breakage of overhead transmission line. The amplitude of 5 kinds of lightening voltage influenced by the insulated overhead transmission line is also calculated. The results show that all the amplitudes of the overvoltage will decrease and the existing overvoltage prevention methods already meet the requirements. According to the development process, dredging and blocking methods to prevent lightning-caused breakage of transmission line are proposed. This work will provide safe and stable operation guidance for the medium-voltage distribution system with insulated overhead transmission line.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.