Characteristics of Dissolved Gas Evolution Rate under Different Loading Factors

Dissolved Gas Analysis (DGA) is the most impactful technique for detecting gas abnormalities in transformer insulating oil due to thermal and electrical stresses encountered during transformer operation. The interpretation of DGA results is critical. IEEE C57.104 is a global standard for extracting knowledge from the DGA results. This standard has been modified numerous times in 1991, 2008, and most recently in 2019. The latest standard of IEEE C57.104-2019 shows significant revisions to the previous one. The most significant amendment to this standard is the addition of dissolved gas evolution rate as a reference value for detecting abnormal power transformer operation behavior. The loading factor of a power transformer is indicating its operating characteristics and is a critical factor in determining the insulation reliability of the transformer. Managing proper load distribution for power transformers based on their DGA status may be able to help keep them healthy. Therefore, a field study is conducted to determine the effect of the loading factor on the rate of dissolved gas change. The final result shows the correlation between the loading factor and the dissolved gas concentration yearly rate of increase. Additionally, the correlation between the loading factor and the age of the transformer is more visible in older transformers than in younger transformers.