Hybrid flow betweenness approach for identification of vulnerable line in power system

Most previous research on the identification of vulnerable line in power systems based on topology betweenness or electrical betweenness suppose that power flow is transferred only along the shortest path. In this study, the hybrid flow betweenness (HFB) is defined by considering the actual path of power flow. The betweenness covers the direction of power flow and the maximum transmission capacity of line with a more comprehensible physical background. Electrical coupling degree between the lines and outage transfer distribution factor is also considered in this model to quantify physical network connection and fault effect between lines. The tenacity and directed global efficiency are introduced to measure the effects on network structure and power transfer caused by fault of vulnerable line. The simulation results of the IEEE-57 bus system and the China southern power grid show that the lines with higher HFB play important role in network structure and power transfer of power grid. The chain attack on these lines would make serious damage on system. The results prove that the model proposed in this study can fully embody the physical characteristics of the power grid, efficiently and accurately identify the critical line of power grid.