Research On Condition Maintenance Decision Making Method Of Transformer Based On Grey Theory

The power transformer is one of the important equipment in the power system, theoperation reliability of the transformer take an important act on the security andstability of power system. Therefore, it is particularly important to access the healthstatus of power transformers and make maintenance decision. For a long time, theplanned regular maintenance has been become maintenance methods, its shortcomingsare not based on actual operating conditions of power transformers to determine themaintenance, but according to the maintenance cycle of the maintenance of order,making the compulsory maintenance principles, but it lack the clear maintenanceobjectives; and make no effective allocation of human and financial resources,increasing maintenance costs, resulting the waste of resources. But the statemaintenance of the equipment from the starting line monitoring and on-line test todetermine health status of the equipment, and the maintenance objectives are clear,maintenance is only in need of repair; in terms of maintenance costs, it is moreeconomic. The state maintenance has been more widely recognized in industrialproduction, therefore, it will become a trend instead of planned regular maintenance.According to the nature of the status maintenance, the health assessment must bebased on online data and operating experience, and then in accordance with theconclusions of the assessment , making a maintenance decision , which is the basicprocess of the state of maintenance . Access to a large number of domestic and foreignliteratures , the following aspects have been studied in the paper. The paper introducesthe analytic hierarchy process and gray clustering methods to assess the powertransformer healthy state. Firstly, using the analytic hierarchy to classify the state ofthe power transformer, transforming the qualitative indicators into quantitativeindicators, and constructing a hierarchical judgment matrix to calculate the combinedweights of the various indicators in the transformer weight. Secondly, comparing theadvantages and disadvantages of the health status of the power transformer, fivedevice status are established, defining as five grey classes, then establishing thewhitenization weight function of the grey classes. According to the gray clustermethod, combining the combined weights with the whitenization weight, to calculatethe status of the transformer.The multi-attribute intelligent grey target decision model apply to the maintenance decision of the power transformer, establishing a set of countermeasures of thetransformer, and selecting the decision-making target from the economic and securityaspects., The case of hit the bull’s eye of the objective effect value is fully considered;its decision-making calculation steps are given, and apply examples to analyze themethod.In accordance with the relational degree of the decision-making situation effectvector and the optimal effect vector, apply the grey relation decision-making to themaintenance decision-making of the power transformer, establishing a set ofcountermeasures of the transformer, and selecting the decision-making target from theeconomic and security aspects, and apply fixed weight and variable weight to studycomparatively to the decision objective, By comparison, the variable weighteddecision-making is more realistic , to make qualitative analysis and quantitativeanalysis be complementary , and reduce the decision-making errors.