Combined Defects Recognition in the Low and Medium Temperature Range by Results of Dissolved Gas Analysis

Abstract

A comprehensive analysis of the oil gas content of 125 high-voltage transformers with combined defects in the low and medium temperature range was carried out for the first time ever. The values of gas percentage and gas ratio for each of 14 defect types were obtained. New 12 nomograms and graphic areas for combined defects in the low and medium temperature range were obtained firstly. The reliability of data recognition using known standards and methods was analysed. The given data allow increasing the reliability of defect type recognition by results of analysis of gases dissolved in oil.