A Contribution to the Analysis of Frequency Response and Impedance Measurements to Evaluation and Diagnostic of Power Transformers

This paper has an objective to show a developed quantitative criterion, based in two mathematical variables that explicit the deviation degree of a normal situation, applying simultaneously data from terminal impedances and frequency response. Based in more than 100-measured equipment, of different applications (step-up transformer, transmission transformer, etc.,), for a period of 10 years, the work presents some examples of practical application of this methodology in Brazilian Electrical System.