The Research And Application Of Risk Assessment On Substation Based On Vulnerability

With the improvement of intelligent level in substation,the center of the power system,the data exchanged between grew more complex of Substation Automation System.While the node of Substation Automation System was affected by external disturbances and produce risk,they would influence to some extent to the neighbor-node and strong correlation-node,which expand the scope of risk.Risk propagation can result in node more vulnerable that may cause cascading failures while they breakdown.The logic network of substation can be abstracted a network that composed of nodes and logical connection.Therefore,the network theories are able to research mechanism that risk spread propagation and the evolution of cascading failures in substation.To solve the problem that ignored the phenomenon risk accumulated step by step in previous studies of risk spread propagation.This paper proposed a model for risk spread propagation based cumulative effect,which described the risk of node.The model can determine the order of neighborhood-node and the risk of delivery,by analyzed the probability of each risk transmission path.Then,we determined the risk spread way after initial node disturbance.In the same time,we located vulnerability that most security threats by accumulated the risk of each node in the network.In order to overcome permissible tolerance parameter of logical nodes cannot be adjusted to the state of network evolution,this paper improved model of effective properties which was suitable for substation automation system was implemented.The concept of closeness centrality was proposed to measure the importance of node in information transformation and adjusted permissible tolerance parameter of logical node dynamically.Meanwhile,to evaluate of cascading failure damage more accurately,we proposed a method of the average network performance measurement,for which suitable substation automation system,according to the characteristics of the distribution of station level,bay level and process level.An experiment of T1-1 substation was conducted.A complex network was built by incidence relation of logical node,to which according the standard of IEC 61850.On this basis,we located relevant vulnerability by different risk source analysis.Then,the efficiency loss under the different cases was contrasted.The experimental results indicate that the model was adapted to analyze risk assessment of substation.Finally,in order to meet the administrator intuitively display running-data and predict demand,a simulation platform of dynamic risk assessment was developed,on which based Substation 3d visualization.The platform integrated the algorithm of risk spread propagation and the algorithm of cascading failures analyzed by the model ofeffective properties.It can reduce management costs.