Modelling and Vulnerability Assessment of Intelligent Electricity Networks as Cyber-Physical Systems

The future grid is different from the current system, and requires more interactions between electrical network and data communication network from the end users to generators. The electrical network acts as a power supply for communication nodes, and in turn, the communication network transmits the control messages for the electrical components. Because of this interdependency, any problems exist in either of these networks may threaten the stability of the whole system. We focus on analysing the vulnerability of the interacted power network and communication network from perspectives of topologies and system operation. An interdiction model is proposed considering the security and operation of both power and communication networks to recognise the crucial set of power components. We solve the interdiction problem using a decomposition method with the consideration of the interdependency between power and communication components. We propose a practical smart grid model as two mutually dependent complex networks with improved interlinks allocation strategy. Moreover, we study the problem of intentional attacks targeting to interdependent networks generated with known degree distribution or distribution of interlinks. In both models, each node's degree is correlated with the number of its links that connect to the other network. Detecting the community structure of a power network can effectively improve the availability of the control actions, which can enhance power system's resilience. This work proposes a method to group the power components into overlapping communities based on the linear sensitivity of the electrical network and complex network theory. This work provides a guidance for the design of the distributed power control system and the power system operation planning