Fuzzy approach for residual life assessment of paper insulation

In this paper, an effort has been made to explore the usefulness of DP (Degree of Polymerization) of cellulosic insulation paper (CIP) to monitor the condition of the transformer. The residual life of CIP of the oil-immerged power transformer is determined by detecting the content of dissolved carbon oxide and 2-FAL gases in oil. The proposed work employs Fuzzy Inference System (FIS), which offers preeminent response for calculating extent of degradation of the CIP. Using the FIS the final condition of CIP is categorized as AI (Acceptable Insulation), MD (Moderate Deterioration), ED (Extensive Deterioration) and UR (Urgent Replacement) from correlation between accumulated values of 2-FAL, CO and CO2 with DP. Furthermore, the best fuzzy membership function has been obtained for the experimental test condition. Finally the results obtained shows that the proposed method accurately monitors the condition of CIP in the oil-immerged power transformers.