Condition based maintenance of power transformer: A case study

Power transformers are important and expensive components in electric energy networks. Unplanned outages of power transformers has a higher economical impact, which motivates, preventive tests and diagnosis for tapping the benefit of predicting condition to optimize maintenance and increase reliability of power system. Application of advanced diagnostic techniques for power transformers, provide the means to enhance the conventional maintenance program. Therefore it is necessary to change from time based maintenance program to a condition based maintenance which uses some of the current diagnosis methods (e.g. Oil test, DGA, PD, Thermography etc.) to determine the condition of the transformer. A case study on condition based maintenance of power transformer by analyzing the DGA results and zeroing towards the problem through proper online and offline tests has been depicted in detail.