Study Of Transformer Insulation Condition Assessment Method Based On Unascertained Theory And Matter Element Analysis

Equipment maintenance is the main component of production and management, it is great significant to ensure safe and reliable operation of equipment by advanced maintenance model. With the increasing number and manufacturing levels of grid equipment, the maintenance management of electrical equipment is transformed progressively from the time-based maintenance to condition-based maintenance. As a key node in the power system, large power transformer is the focus of device management. The research of condition evaluating method can not only be helpful in extending the service life and reducing the failure rate of power transformer, but also be very important to promote the maintenance model transformed to the condition based maintenance.In this paper, the condition assessment strategy of oil-immersed power transformers (220kV) has been studied. First of all, the main reason for deterioration of the transformer condition, the main defect and fault types, the composition of transformer state information and data sources has been analyzed. The transformer condition assessment index system has been established based on the analysis. Secondly, the relative importance of each index was quantified and the appropriate method for adjusting weight was found. Finally, the transformer status information data processing method and the state evaluation method has been studied. The main achievements of this paper are as following:â‘ A calculate method based on unascertained mathematics theory was presented to determine the initial weight values of assessment indicators. The impact of the experts'subjectivity on the results of index weight was effectively reduced by constructing the unascertained rational numbers. Then the entropy method is proposed to modify the initial weights to adjust the dynamics difference of the specific issues. It is combined the static weight and dynamic weight, so the reasonableness of the calculation results has been strengthened, and it can make some potential abnormalities get a timely reflect.â‘¡The synthesis transformer condition assessment model is structured based on matter-element extension evaluation method. The method can evaluate the status of transformer perfectively by constructing an appropriate evaluation indicators correlation function. The correlation fuction value is positive when the transformer is in the normal operation, and it turns to negative when the indicators have qualitative change. The synthesis transformer condition assessment model based on matter element extension evaluation method can not only reflect the status of transformer more precisely, but also quantify the extent of the deviation.â‘¢The cases analysis show that the power transformer condition assessment methods based on unascertained theory and matter-element analysis can easily use relatively small transformer assessment indicators to achieve an accurate result. It can provide a reference to the arrangement of maintenance procedure.