Modeling and Analysis of Cascading Failures in Cyber-Physical Power Systems Under Different Coupling Strategies

Abstract

The cyber-physical power systems(CPPS) may experience cascading failures due to damage to power transmission lines. This paper focuses on modeling and analysis of CPPS with grid-line random failure under different coupling strategies to reveal the coupling mechanisms between the power grid and the information network. The CPPS mainly includes the power grid, information network, and the coupling connections between them. An uncertain failure mechanism is introduced in the cascading failures model to determine the failed power lines. The DC optimal power flow calculates and distributes the power flows to determine the tripping rates of power lines. A new comprehensive metric is proposed to assess the critical nodes, which considers both topology and state information of the power grid. According to some assessment metrics, the nodes in the power grid and information network are ranked. The CPPS model is constructed by coupling the power and information nodes in specific sequences. The cascading failures of CPPS are simulated when the power lines suffer random attacks to obtain the most robust coupling method for typical coupled CPPSs.