Modeling And Vulnerability Evaluation Of Cyber-Physical Power System

The intelligentization of power system and the expanding scale of interconnection make the power system more dependent on the safe and stable operation of information communication system,a nd gradually form the deep integration system of power system and information system.The wide application of information communication technology in power system not only improves the reliability and controllability of power system,but also forms a new w eak point because of the deep fusion between the two systems.Failures of information communication system may interactively propagate between systems,resulting in the occurrence of large-scale cascading failures.Based on the above background and the theory of interdependent network,this paper establishes a reasonable interdependent network model for the power information communication system,and identifies the key nodes in the information communication network,based on the operation characteristics of the two power networks,the inter-network failure model is constructed and the vulnerability of the power information interdependent network is analyzed.When modeling and analyzing the interdependent network,the architecture of power and information communication deep fusion system is described in detail.Based on the complex network theory,the model of one-side Power Network and Information Communication Network is established,and the dependence between the two networks is analyzed.Then the correlation Matrix is used to represent the topology and weight model of the interdependent network.Finally,based on the interdependent network modeling method and mathematical model,the interdependent network modeling and analysis of the actual provincial power station and the corresponding power communication network are carried out.In order to identify the key nodes of information and communication network effectively,this paper presents a multi-index evaluation system node identification method from three aspects: Topology,communication service and power network impact based on the interdependent network model.Firstly,according to the weighted topology and the degree of node cohesion,the topological importance of the static network is calculated based o n the node shrinkage method.Secondly,the relative importance value matrix is constructed according to the experts’ evaluation of power service and power network impact,and the evaluation method is formed to replace the subjective evaluation of the import ance degree with the objective one.Then,we use the analytic hierarchy process and the entropy weight method to obtain the subjective and objective weights of each influence index,so as to establish the comprehensive weight evaluation system of node impo rtance.Finally,according to the amount of information obtained by the attacker,the vulnerability of the interdependent network is evaluated by using the modified effectiveness as the vulnerability index.In order to reveal the topological characteristic s of the interdependent network,firstly,by analyzing the component configuration and the inter-network dependence of the power network and the multi-layer Communication Network,according to the actual power network topology,a network model which accord s with the structure characteristics of interdependent network is established.Secondly,according to the connection characteristics of various components in the interdependent network,the dielectric attack index is proposed.Finally,considering the inte raction and failure of components in the interdependent network,and considering the uncertainty of fault propagation between networks,the cascading failure model of the interdependent network is established.Finally,an IEEE39 bus system is taken as an example to construct the interdependent network model,and the vulnerability of the dependent network is measured by the node loss and the efficiency decrease percentage according to the attack index.