Revealing Impacts of Cyber Attacks on Power Grids Vulnerability to Cascading Failures

Cascading failures in power grids are typically triggered by initiating contingencies (ICs). Traditional assumption is that those multiple-component ICs have low chances of occurring. However, considering the increasing cyber events in power grids, this brief reveals that smart attackers can target at critical ICs and implement well-designed cyber attacks to highly increase the ICs' occurrence probabilities by overloading key branches in the grid. This will greatly increase the grid vulnerability to cascading failures. In this brief, such issue is revealed and analyzed using a two-step approach, which consists of a high-probability IC screening and a deterministic cascading testing. The simulation results on the IEEE 118-bus systems verify the effectiveness of the proposed approach and highlight the increased risk imposed by cyber-attacks.