Research On Transformer Condition Maintenance Strategy Based On PIM

With the continuous development of the power grid,in order to ensure the reliable,safe,economical,and high-quality operation of the power system,there are also higher requirements for the normal operation of the transformer.In order to improve the efficiency of transformer maintenance,Taking into account the two practical problems of incomplete maintenance and load fluctuations in the transformer state maintenance strategy,a transformer state maintenance strategy based on the proportional strength model is proposed.First,explain the proportional strength model theory.Use maximum likelihood estimation method for parameter estimation,minimum maintenance cost method to calculate transformer state maintenance threshold value,determine the state maintenance threshold curve of the transformer;add the lower limit value of the threshold value as the restrictive index of the state maintenance strategy,and form the maintenance curve diagram,as the transformer Refer to the figure for decision-making on condition maintenance.When the transformer condition monitoring data point is located in the recommended maintenance area,consider overhauling the transformer.Secondly,establish a transformer condition maintenance model considering incomplete maintenance.The detailed calculation model of the incomplete maintenance parameters in the proportional strength model is given,and the sensitivity analysis of the time parameters and maintenance parameters in the calculation process is carried out to determine the reasonable valu e range;the actual transformer fault statistical data and condition monitoring data are used to carry out the sensitivity analysis.Analyze the calculation example,analyze the effectiveness of the improved proportional strength model in the case of incom plete overhaul from the three aspects of overhaul cost,overhaul times and overhaul time,and quantify the degree of restoration of the transformer state by the corresponding overhaul activities,in order to consider the incomplete overhaul.Provide a theo retical basis for the decision-making of transformer condition maintenance.Then,in view of the load fluctuation of the line connected to the transformer,a transformer condition maintenance model considering the load fluctuation is established.The first-order electric heating model and the life prediction algorithm based on the proportional intensity model are used to determine the relationship between the load fluctuation and the proportional intensity model.The actual transformer fault statistics,condition monitoring data and corresponding load data are used to analyze the calculation examples.From the process of load—transformer hot spot temperature—life change—condition maintenance threshold change,the specific influence of load fluctuation on the transformer state is calculated,and the load fluctuation of the transformer is obtained.Affected condition maintenance threshold curve,and formulate a condition maintenance decision diagram.It provides a theoretical basis for the decision-making of transformer condition maintenance considering load fluctuations.Finally,the GUI interactive interface of transformer PIM state maintenance analysis is developed through MATLAB.Emphasize the introduction of the program’s interface,functions and usage methods,simplifying the analysis of the transformer’s status maintenance data.