Key Node Identification And Vulnerability Analysis Of Power Communication Coupling Network

With the development of smart grid construction and large-scale interconnection of Power Grid,Power Grid is increasingly dependent on the safe and stable operation of the information communication network.What's more,the whole system has evolved into a deep-coupling power communication coupling network.The development of information systems improves the observability and controllability of the power network and because of the deep coupling relationship between them,the faults in the communication network may propagated between the coupled networks,even lead to large-scale interactive cascade failures.Therefore,identifying the key nodes in the power communication network and establish ing the cascading failure model which can reflect the characteristics of unilateral network and analyzing the vulnerability of power communication coupling network has important theoretical value and engineering significance.The main work of this paper are shown as follows:Due to the important position of today's power communication network in Power Grid and focusing on the industry background of the power communication network,the topology of the communication network and the communication service and impact on the power network are considered.A multi-index evaluation system for node importance is constructed.The analytic hierarchy process and the entropy weight method is used to integrate the subjective and objective information to obtain the comprehensive weight.The important degree and weight of each index is used to obtain the comprehensive importance of each node.Finally,analysis is performed by an actual power communication network.compared with the existing method,this method can better integrate the key nodes in the network with the industry background of the network.In the current study of interdependent networks based on seepage theory model and load-capacity model,the same failure mechanism is adopted in two networks,which can't reflect the physical characteristics of the singl e network.Therefore,in Power Grid,the load and capacity of node are introduced to load-capacity model.The percolation theory model is used in the communication network and the cascading failure model,which has different failure mechanism betweens the two network,is built to reflect each network characteristic.The power communication coupling network is built in which IEEE57 bus system is regarded as the power grid and the double-star and mesh communication network are respectively considered.The impact on power communication coupling network from the factors is studied which includes the attack mode,coupling connection mode,the average node degree of communication network and the tolerance of load.The simulation results show that compared with random attack modes,the system is more vulnerable under the malicious attack mode,the coupled network has better robustness according to th e node degree heterogeneous connection,and enhance the average node degree of communication network and the tolerance load can improve the ability of resist cascading failure.In the cascade failure model of different failure s mechanisms of coupling network,the important impact on load distribution strategy on the network is considered.The power communication coupling network constructed with IEEE57 bus system and two typical communication networks is regarded as the research object.A more realistic load distribution strategy is proposed.Compared with common load distribution strategy,the ability of the coupled network to resist cascading failures is verified.Finally,found the ability of the network to resist cascading failure can be improved by r easonably setting the residual load capacity coefficient and the load distribution efficiency coefficient.