Vulnerable transmission line identification considering depth of K-shell decomposition in complex grids

Vulnerable transmission lines are weaknesses in the power system security, which are easy to induce cascading failures and blackouts. To identify the vulnerable transmission lines with the increasing complexity of the interconnected power grid, the authors propose a vulnerable transmission line identification method using the depth of the K-shell (Ks) decomposition under power transfer (named the DKsPS method), which fully considers the dynamic characteristics of the power transfer and transmission capability after the power grid fault. This method establishes a correlation network based on the correlation matrix of transmission lines under the N − 1 check and then identifies the vulnerable transmission lines by using the modified Ks decomposition. Numerical simulations on both the IEEE-39 bus system and the Northeast China power grid verify the validity and accuracy of the DKsPS method.