Analysis on Measures of Improving Lightning Withstand Level of 10kV Overhead Insulation-covered Conductors

The lightning parameters of 2001～2007 in Chongqing Jiangbei District were collected by lightning location system(LLS) and sta-tistically analyzed.Simulation model established by electromagnetic transient program(EMTP) .Analyze and compare the effect of improving lightning withstand level by line surge arrester in different programs.The influence of impulse grounding resistance of towers and the locations where lightning stroked are analyzed.The results showed that installing the line surge arresters can effectively improve the lightning withstand level of transmission line.The measures, such as reducing grounding resistance of towers, installing metal oxide surge arrester with series gap and arc-protection hardware with stabs, can effectively reduce the rate of flashover and lightning-caused breaking of covered conductors of 10kV distribution lines.