Power System Operation Risk Assessment Based On Condition-based Maintenance

At home and abroad in recent years, the frequency of large blackouts caused thewide attention to the power grid operation risk problem from all around the world.How can we carry out the risk assessment on the grid accurately, find out weak linksof the grid and avoid the run risk of networks has become an important subject atpresent.The traditional power grid operation risk evaluation method can hardly meet theincreasingly complex operation characteristics and structures of the grid. After theapplication of the risk theory to the evaluation of power grid operation risk, and theanalysis of the related basic concepts of the risk theory and the related theory ofpower grid operation risk evaluation, the technical scheme of the power gridoperation risk assessment is proposed based on the state overhaul. The power gridoperation risk assessment based on the state overhaul is beneficial to improve theaccuracy and credibility of the data in the operation risk assessment.Analysis shows that the equipment failure plays an important role in power gridoperation risk assessment. This article applies the equipment failure rate algorithmwhich is based on the state overhaul to the power grid operation risk assessment, andproposes the transformer state evaluation based on the theory of fault tree andanalytic hierarchy process, and the transmission line state evaluation based on thefuzzy comprehensive evaluation method.The fault tree method introduces the selecting methods of the comprehensiveevaluation index system of the state of transformer, and sets up a reasonablecomprehensive evaluation index system of transformer, and also proposes thetransformer state comprehensive evaluation model based on the analytic hierarchyprocess with3scales. Then it uses the equipment failure rate calculation model tocalculate the equipment failure rate, which reduces the influence of artificial factorseffectively, and improves the accuracy and reliability of transformer failure rate.The transmission line state evaluation model is put forward by the fuzzycomprehensive evaluation method, and calculate the failure rate of the transmission line by evaluating the results. This article establishes the multi-level transmission linestate evaluation index system which contains eight level indicators and31secondaryindicators; and the weight of each index can be analyzes through the analytichierarchy process with3scale, and the state evaluation results of transmission linecan be achieved by fuzzy synthetic method; and it uses the score results and therelations between the failure rate to calculate the failure rate of transmission line.