Dual nature of cyber–physical power systems and the mitigation strategies

Cyber–physical power system (CPPS) offers benefits in terms of enhanced grid operation and improved performance, but it also brings forth new threats to the power system posed by digital intelligence. In this paper, we propose a general cascading failure model to analyze the vulnerability of CPPS when facing various attack modes (physical attacks and information attacks). In addition, we introduce an all-type connected islands (ACI) mechanism in model to reflect the fact that a well-working island should contain all types of nodes. Then we conduct experiments under different scenarios, such as different attack modes, different coupling strategies, and different power flow calculation models. Our findings demonstrate that, on the one hand, the introduction of ACI enlarges the cascading failure size in CPPS. On the other hand, the double-edged sword effect of CPPS exists in various scenarios. Furthermore, given the potential threat of information attacks, we propose a fused centrality index from the perspectives of structure and function, and apply it to two mitigation strategies before and during the cascading process. Experimental results show that these strategies are effective in mitigating the damages of the information attacks.