Research And Application On Parallel Gap Lightning Protection Device

Transmission lines are the most important equipment in power systems in which large length and complex environment, the degree of reliable operation is directly related to the safe operation of power systems. How to ensure safe and reliable operation of transmission lines is significant. Transmission line fault caused by lightning strikes accounted for a large proportion of, in recent years; statistics show that lightning fault accounted for 70% of the total failures in our country.This article was developed the parallel gap lightning protection device for overhead transmission lines, which resolve the issue of permanent failure. The idea is to allow the transmission lines have some lightning trip rate, although the trip, but the auto-reclosing is success without permanent fault.Firstly, collection and field research a number of Power Grid parallel gap lightning protection device operation data, and with the lighting situation in southern China to optimize the design for parallel gap in the region, and processing the samples.Secondly, Electrical field was computed to composite insulator installed parallel gap device and porcelain insulators installed parallel gap device by ANSYS. And experimental test was done to those. Include these tests, visible corona tests and radio interference tests, power frequency arc burning characteristics tests, lightning impulse U50% and V-S characteristics tests.Thirdly, Lightning tripour rate of lines installed the parallel gap device was computed.Fourthly, The parallel gap devices have simple structure and assemble easy and applicable to engineering project. The parallel gap lightning protection device had been used on several 110kV overhead lines in Dongguan area. After 1 year storm season, several actions have been recorded and the equipment proved effective.Finally, this paper summarized the work done, and the backbone transmission network in the massive use of parallel gap was discussed.