Topological multi-contingency screening based on current flow betweenness

Security assessment considering multi-contingency is necessary since the complexity of the power system is constantly increasing. This paper proposes a topological method to screen critical transmission lines and buses under multi-contingency of transmission lines. It is based on a topological measure called current flow betweenness centrality, and provides a structural analysis of the system, requiring no knowledge of its electrical measures. The proposed method is applicable to the local and global contexts. The local analysis identifies how transmission line outages affect each bus, whereas the global analysis identifies the impact of multi-contingencies, detecting potential overloaded buses and transmission lines that can trigger large blackouts. An exhaustive search formulation of the method is presented, followed by an optimized search approach for large power systems based on the Differential Evolution algorithm. Numerical analyses are performed for ITAIPU 11 bus, IEEE 39 bus, IEEE 57 bus, IEEE 118 bus, and Polish 2383 bus transmission systems. This work reports promising results with the utilization of current flow betweenness to identify critical lines and buses when compared to the literature. Since our method works even when traditional measures of the system are unavai-lable, it reaches the needs of complex grids and can be applied as a pre-analysis tool.