Study On Reliability Life And Economic Life Of Power Transformer Based On Health Index

At present, power companies mainly focus on the reliability of the transformerwhen making the power transformer maintenance and retirement plan. Thus, this kind oftactics often leads to the phenomenon of excessive maintenance and early retirementand also is a tremendous waste of resources. For a long time, the current transformerinsulation condition assessment methods cannot well solved the incompatibility ofassess factors and different degree of influence, meanwhile the research on assessmentof reliability life and economy life of the transformer has rarely been reported.Therefore,it is necessary to research transformer insulation condition assessment, reliability lifeand economic life assessment by considering the reliability and economy of transformeroperation, so that appropriate plans of maintenance and retirement can be developed,which can simultaneously improve the level of lean management of electric powerenterprise. Accordingly, this research project is of great theoretical significance andengineering value.This paper analyzed the optimization of the transformer features related to thetransformer condition and established insulated condition assessment system, then atransformer insulation condition assessment method based on the foundation of set-pairanalysis and evidence theory fusion was made,. The calculation model of health indexand fault probability was made based on the aging law of transformer. A transformerreliability life assessment model was established, considering the operating laws andsingle transformer influence. Finally according to the fault rate curve, economic factorsrelated to the transformer were analyzed and transformer economic life assessmentmodel was established in the maximum principle of average annual net income. Themain innovative conclusions of this thesis are as follows:On the basis of the establishment of the insulating condition assessment indexsystem of the transformer, the right indexes weights and weight adjustment method,when the indicators are missing, are determined. The indicators ambiguity are treated byset-pair analysis theory, and different factors status information are fused by evidencetheory. The method of combining the maximum membership principle and theconfidence criteria principle are introduced to determine the state of the transformerrating, which means an eventual transformer insulation condition assessment model isestablished. A case study shows that the model is accurate and effective.On the basis of the aging laws of the transformer, comprehensive health index and the probability of failure model of the transformer are established, considering thefactors such as the transformer insulation state, operating environment, maintenancerecords, accessories and other conditions. Combining the effects of statistical laws andsingle transformer impact, the reliability life assessment model of the transformer isultimately established. The case study shows that the model is feasible and effective.On the basis of the analysis of the economic factors associated with thetransformer, the power supply revenue, operating and maintenance costs, accident riskcosts, depreciation costs and direct broad overhaul costs are calculatedrespectively, toestablish an overhaul or replacement of annual net income model. Average annual netincome is regarded as a criterion to assess the eventual establishment of the economiclife of the transformer model. Case studies demonstrated the effectiveness of the model.