Study on risk of lightning flashover of regional power grid

The domestic large-scale power blackouts occurs so frequently that more scholars concerned about the cascading outages of power system and the research of fragile domain. Based on the complex network theory and from the perspective of network efficiency, this paper analyzed the inherent fragile domain of power transmission network and had the risk assessment of lightning flashover of the weak field lines through the research of topological properties of the grid and chain dynamic fault simulation. Firstly, based on network topology mode, we proposed two methods based on edge betweenness of cascading outages model and its algorithm, analyzed the static structural properties of network and chain dynamic fault simulation, and qualitatively analyzed the impact of the topological characteristics of the power to the transmission of cascading outages. By calculating the efficiency of network and the loss of value of the network efficiency on failure modes to measure each edge´s impact on network performance and then we figured out the fragile domain which influence the performance of the transmission network. Secondly, we analyzed the trip-out rate of specific lines of fragile domain according to the procedures and tried to find out the lines with higher trip-out rate. Finally, we established a lightning flashover risk model of regional power grid to rank the lightning flashover risk of the current grid, in order to provide a theoretical basis to optimize the lightning protection measures of power grid.