Power Transformer Condition Evaluation by the Analysis of DGA Methods

Power transformer condition evaluation by the analysis of insulating oil is presented in this paper. Evaluating the condition of power transformer by means of Dissolved Gas Analysis (DGA) has been a famous approach for insulating oil analysis to find out incipient faults in transformers before catastrophic damages occur. Diagnostic tests of power transformer are classified into five types: key gases, roger ratio, Doernenburg, IEC and Duval triangle methods. The study was further done to investigate the accuracy of each method in predicting the fault and the consistency of the methods. Then the result of this work is useful for planning an appropriate maintenance strategy to keep the power transformer in acceptable condition.