Hierarchical Game‐Theoretic Defense Strategy for Coordinated Attacks in Hybrid AC/DC Cyber‐Physical Power Systems

ABSTRACT This paper proposes a game‐theoretic optimisation framework for designing attack and defence strategies in hybrid AC/DC cyber‐physical power systems (CPPS). The proposed framework employs a three‐layer planning hierarchy. The upper layer introduces a novel target importance index combining complex network theory and power flow entropy. The middle layer incorporates attack success probability and defines a multidimensional damage index based on topology reduction, load loss and power flow deviation. The lower layer develops an optimal dispatch model integrating economic cost and security penalties, addressing both normal operations and emergency responses. Simulations on a modified IEEE 39‐bus system demonstrate that the framework improves defence efficiency and system resilience, whilst revealing a diminishing marginal effect in defence investment. The analysis further quantifies how defence sensitivity parameters affect attack suppression, supporting resource allocation decisions. This work offers a scalable solution for enhancing CPPS security against cyber‐physical threats, with potential extensions to adaptive and cooperative defence strategies.