Evaluation On The Vulnerability Of Transmission Grid Based On Risk Theory And Prevention Study

Along with the expansion of power system, and increase in the complexity of infrastructure,and the intervention of power market, people proposed higher requirements for the operation of power system. This also promoted power system vulnerability analysis to become one of the most challenging problems for system operators. At present, how to analyze accurately, and evaluate the grid current vulnerability has become the research hotspot in this field.But the physical variables for the characterization of power system are numerous, and the relationship among them is close. When building network vulnerability evaluation index, how to seize the main physical variables, and to ignore the minor physical variables is not only the foundation of network vulnerability evaluation, but also a key part. This paper adopts a method for comprehensive evaluation transmission network vulnerability based on risk theory.Firstly, this paper proposes the node and line vulnerability assessment indexes which consider both the network structure and the operation state by summarizing and analyzing the vulnerability evaluation. The calculation of these indexes is obtained by the results of tracking the power flow based on circuit theory. Secondly, the paper also considers the impact of equipment failure rates on equipment vulnerability, and the equipment failure rate is obtained of the state maintenance data. Finally, this paper uses the utility theory to evaluate the consequences of failure for disconnection fault, get the corresponding comprehensive static risk index.Define the line comprehensive vulnerability evaluation indexes based on the branch vulnerability evaluation indexe and the comprehensive static risk index.5 machine 14 nodes system as an example verify the effectiveness of the proposed assessment method. At the same time put forward the corresponding preventive measures to the identified vulnerable parts.