Comparison of time and frequency method in fault detection for transformer windings

In the article is description of the contact analysis of power transformers 22/0.4 kV with insulation oil-paper by time impact tester and frequency impedance analyzer. Both methods are most often used for the analysis of mechanical components (mainly windings) of power transformers. The diagnostic measurement allows finding fault state in transformer parts. Theoretical and experimental research at power transformer by frequency and time area is presented. Within analysis, mutual courses comparisons for both methods were performed using mathematical correlation methods. Thanks to this mathematical analysis, an interthread short circuit was found on the transformer primary winding.