Study on Lightning Flashover Risk Assessment and Lightning Protection Measures of a 220kV Line

In recent years, lightning accidents occur frequently in power grid. 220kV transmission lines with low insulation level are prone to trip due to lightning strike, which directly affects the production and living electricity consumption in surrounding areas. In order to improve the lightning damage resistance ability of transmission lines and reduce the lightning trip rate, it is necessary to effectively improve the lightning protection performance evaluation and treatment level of transmission lines, and to design and transform the lightning protection facilities economically and reasonably. Based on the line parameters, a large number of lightning monitoring data, the improved electrical geometric model and ATP/EMTP method, the winding and attack trip rate of a 220kV DC transmission line has been calculated. Combined with trip rate index, the risk assessment of lightning hazard has been realized. The distribution of ground lightning density along the transmission line corridor has been obtained by using line corridor grid method. Combined with the actual tripping rate index, the mine hazard risk assessment of the line base by base tower has been realized. According to the result of risk assessment, combined with the characteristics of various lightning protection measures, choose to install the lightning arrester, install the side needle to prevent around the impact and reduce the resistance of three measures for lightning protection transformation.