Cyber-attacks against cyber-physical power systems security: State estimation, attacks reconstruction and defense strategy

Abstract In modern power systems, the connection between cyber part and physical part is more and more close and deeply coupled, while cyber-physical power systems (CPPS) can exactly describe the dynamic process of modern power grids. The problem of secure state estimation and attack reconstruction of cyber-attacks corrupting states of CPPS is addressed. First, the classical small signal model of CPPS under disturbance and cyber-attacks is established. Then, an intermediate observer is proposed to realize the security state estimation and state attack reconstruction of CPPS under cyber-attacks, meanwhile, the linear matrix inequality (LMI) is used to solve the parameters of the intermediate observer. Finally, an attack defense strategy satisfying optimal economic dispatch is proposed. Case studies are presented to assess the effectiveness of intermediate observer reconstruction and the effectiveness of defense strategy.