Research On The Cascading Failure Of Cyber Physical Power System Based On Community Theory

With the improvement of the intelligent of power system,the combination of power network and cyber network becomes more and more close and gradually develops into a complex cyber physical power system(CPPS),The deep coupling of power network and cyber network brings flexibility,high efficiency and new uncertainty.It faces the challenges of security,fragility,incomplete system model and so on.The complexity of the CPPS makes the failure can be injected from the cyber network,which affects the security of the power network.The failure of the power network can destroy the stable operation of the cyber network,and it is difficult to analyze the interaction between the power network and the cyber network in isolation.However,As a mesoscopic scale of complex networks,communities are rarely used in the research of CPPS.Based on the above background,this paper uses the complex network theory to model the cyber Physical Power System,and studies the influence of community on the CPPS cascading failure.The work is as follows:In order to study the influence of community structure change on network robustness caused by the location of control center,In view of the shortcomings of the scale-free network generation algorithm with community structure used in the current literature,this paper modifies it to generate communities of different sizes and adjust the connection probability of each community.Based on the interdependent network model,a simulation method of cascading failure considering the island operation of the power network and cyber network is proposed.The proportion of the residual nodes in the network is used as the evaluation index,and power grid and cyber network adopt assortative coupling in communities.In this paper,the global connection probability,community connection probability and the effect of multiple control centers on the cascading failures of CPPS are studied while the control center in different societies.Considering the power flow distribution of power grid and the real-time dispatching function of cyber network,a minimum load reduction model with node dispatchability and line observability is established.A vulnerability assessment index of CPPS at community level is proposed,and a cascading failure simulation method considering the interaction between energy flow and information flow is established.In view of the current situation that the modeling of information network is not unified,a topological consistent cyber network and a scale-free cyber network are constructed for comparison.The degree-to-degree coupling between cyber network and power network is used to study the impact of community connection edge attack,community inside edge attack under two kinds of cyber networks,and to compare the situation of cyber network and non-cyber network when community-side attack occurs;study the impact of community-inside edge attack and random power edges attack when the cyber layer of power community is disturbed under two kinds of cyber networks.