Research On Cascading Failures For Cyber Physical Security In The Smart Substation

The smart substation is an important part of the smart grid,with the increase of the size and complexity of the smart grid,cyber security and physical security of the smart substation is no longer two isolated problems,it is necessary to regard the smart substation as a cybe physical system to analyze the cyber security and physical security,especially the cascading failure for the cyber physical security.The traditional substation security research studies its cyber security and physical security in isolation,without clarifying the relationship between the two.In this paper,the research on the security of smart substations is done with the perspective of Cyber Physical System as follows:First of all,combing the research object,the traditional substation physical security research and cyber security research results and the measures to protect them,proposed a hierarchical model of the smart substation for cyber physical system and according to the hierarchical model of smart substation,described the security risk,the risk reason and the risk consequence of each layer of smart substation are in detail.Then study the percolation theory and based on complex network theory combining the smart substation cyber physical system with the percolation theory.This paper analyzes the cascading failures in the smart substation facing the cyber physical security and proposes the cascading failures model of the smart substation cyber physical system.An example of failures propagation and a detailed mathematical analysis are given.Finally,a large number of simulation experiments were carried out to verify the influence of different parameters on system robustness.The results of this paper show that the reliability of smart substation cyber physical system is related to the power law index of the network.It has no relation with the size of the cyber physical system network and the proportion of the two networks.The cyber physical system with strong connectivity will be more good risk prevention.The research also shows that there are different thresholds for smart substation systems with different connectivity.When the ratio of initial faulty nodes is higher than this threshold,the system will collapse.This is of theoretical significance for the study of smart substation defense against sporadic cascading failures.