An Extended Vulnerability Assessment Method for Interdependent Cyber-Physical Power System: Fast and Precise Solution

This letter is devoted to the Vulnerability Assessment (VA) of Interdependent Cyber Physical Power Systems (ICPSs) under different types of simultaneously imposed physical (component outages) and cyber (Denial of Service (DoS)) attacks. Herein, the realistic functional Vulnerability Index (VI) is originally determined based on a modified algorithm based on DCOPF with practical assumptions regarding load shedding and controllability, which is time-consuming as expected. For this modified functional VI, the supply-demand imbalances and line overloading situations are distinguished considering the urgency of their required corrective actions affecting the consequences of uncontrollability. Moreover, focused on both accuracy and evaluation time, a new topological VA framework is developed emphasizing the electrical properties of the power systems in the VI calculation, especially the adequacy. The proposed topological VA framework consists of four simple calculation criteria, avoiding complex optimization problems while checking the network's capability to handle both over and under-frequency cases based on available generation reserve and load flexibility. The correctness and effectiveness of the proposed schemes have been validated based on the simulation results of the IEEE 39-bus system. The proposed topological method reduces the computation burden by 60% while having over 99% accuracy compared to the modified functional framework.