Modeling and vulnerability assessment of cyber physical system considering coupling characteristics

The smart grid is a typical cyber physical system (CPS). Communication networks and power networks have the structural coupling and functional coupling characteristics, which may induce cyber-physical coupling failures. To reveal the vulnerability characteristics of CPS, this paper proposes the CPS interdependence model and analyzes the vulnerability of CPS. Firstly, considering structural coupling of the power and communication system, structural characteristics and networking constraints of fiber optic communication networks, the communication network topology generation model is proposed. Then, based on the generated communication network, the CPS interdependence model is built, which describes the structural and functional coupling between power and communication network. Finally, based on the fault chain theory, the CPS cascading failure analysis model is proposed to assess the vulnerability. In the case study, IEEE 118-bus system is taken as an example to generate communication network, and the validity of the communication network topology model is verified by comparing structural features with actual networks. The influence of the proportion of composite lines (optical fiber composite overhead ground wire, OPGW), and information failure on vulnerability of CPS are analyzed.