Research On Maintenance Decision Making For Power Transformer Considering Economy

The current maintenance decision making for transformer adopted by the power industry is mainly based on the risk assessment model established by the failure probability and risk of equipment,and it often ignores the enormous cost of maintenance.With the increased competition in the industry and rising cost of labor in recent years,the economic requirement for maintenance have to be taken seriously.Therefore,we must fully consider the economic need in the process of making maintenance decision for transformer,reducing the cost of maintenance greatly while ensuring the safety of transformer operation,to establish a robust transformer maintenance system.This paper fully considers the economic factor in maintenance decision making for transformer,guaranteeing the safety of transformer operation while reducing the cost of maintenance,consideration must be given to both the risk and economic of transformer maintenance.First of all,a fuzzy scoring strategy model of transformer is proposed using the idea of fuzzy mathematics.This model uses the fuzzy comprehensive evaluation to score the typical fault types of the transformer.Based on this,a clear comprehensive evaluation model of fault types is established,the overall state evaluation result of transformer can be calculated.The problem that state evaluation result of transformer without subdivision by the rules of the power grid guideline is solved.Changing the state evaluation result of transformer to be a precise numerical value,and laying foundation for calculation of the failure probability.Secondly,defect index is calculated according to the status evaluation of transformer,which can confirm the failure probability before maintenance and reduce the error of data fitting.So as to accurately calculate the risk value before maintenance and judging whether transformer needs to be repair according to the 'As low As Reasonably Practically' principle,which can avoid over maintenance,reducing the waste of economic cost.Because of the method using defect index to calculate transformer failure probability is not related to running year of transformer,the idea of age reduction is adopted to calculate transformer failure probability after different maintenance methods,which can calculate the value of transformer's reduced risk after different maintenance methods.It is a preparation to analytic hierarchy process model of maintenance decision making for transformer.Finally,life cycle cost composition in transformer is discussed,and calculation method of economic indicators related to different maintenance methods is confirmed,and combining the reduced risk values of transformer after different maintenance methods to set up the AHP model for searching the relationship between maintenance risk and economic.The optimal maintenance decision for transformer that take into account both maintenance risk and economic costs is worked out.The validity of maintenance decision making for transformer studied in this paper is verified by an example analysis.In order to make the research results convenient for engineering applications,avoiding lots of fussy and complex calculation steps involved in the maintenance decision making for transformer.Also,taking into account the on-site acquisition of transformer state parameters in the future,the maintenance software for transformer is written by the LabVIEW platform.