Dual graph-based vulnerability evaluation for power grids considering fault correlation by utilizing improved e-index method

Abstract To identify the vulnerable lines accurately and reduce the risk of major outages, a vulnerability evaluation method is proposed based on an improved e -index applied to a dual-graph of power systems. Firstly, the weighted dual graph is established on the branch potential energy to reflect the fault correlation among lines. Then, an improved e -index method is proposed to overcome the inability of the traditional e -index in characterizing the power flow transfer attributes. Finally, the simulations show that the faults of the identified vulnerable lines will cause a rapid increase in load loss and a sharp decrease in Net-ability, which demonstrates that the accuracy and efficiency of the proposed method for different scale power grids.