Improved percolation theory incorporating power flow analysis to model cascading failures in Cyber-Physical Power System

The modern power grid is becoming an interdependent Cyber-Physical Power System (CPPS). The worldwide blackouts revealed the mutual interdependences render the CPPS more vulnerable to cascading failures. The percolation theory is a useful tool to analyze and simulate the cascading failure in interdependent networks. However, the current percolation theory is based on purely topological analysis. This paper presents an improved percolation theory which incorporates the AC power flow analysis to model the dynamic developing process of cascading failures in the CPPS. The simulations of cascading failures in the CPPS with various interface and node attack strategies demonstrate that the topological centrality interface strategy shows better robustness, while the topological centrality based node attack could cause heavier damage. In addition, compared with the conventional percolation theory, the improved percolation theory models the cascading failure in the CPPS more exactly and provides more comprehensive indices of the robustness of the CPPS.