Velasquez, Juan; Sanz-Bobi, Miguel; Galceran, Samuel; Sweetser, Charles; DoCarmo, Hyder
The Frequency Response Analysis is a powerful method for the detection and diagnosis of defects and failures in the active part of power transformers. The assessment of the results is based on comparisons in which the results of an actual test are compared to a reference or baseline. Three methods are commonly used to assess the measured traces: time-based, construction-based and phase-based comparison. Unfortunately, in the majority of the cases, time-based comparisons cannot be carried out because of the lack of
fingerprints. In these cases, the constructionbased and phase comparisons can be used. In this work the assessment of FRA results under the different comparison philosophies is illustrated by means of real cases studies.
