Evaluation of Various Transformer Field Conditions Using Cross-Combined Frequency Response Analysis to Identify Specific Deformity

In HV equipment, the most critical and valuable components used is transformers. Power transformers should go through standard diagnostic tests to identify deterioration or to avoid the emergence of defects that might possibly cause severe failure. Frequency Response Analysis already proven to be a promising tool in diagnostic techniques that make use of this understanding to find such changes. FRA has so far been used to detect deformation in transformers by observing changes in the frequency response curve, despite a limited understanding of what caused the changes in the initial case. Several FRA methods have been implemented recently all around the world, primarily for transformer deformation detection and diagnosis. Nonetheless, there is now an increasing amount of research focused on determining specifically the type and degree of deformation in a transformer by looking at its FRA response curve. It is very important to refer to the guidance given in the recently published IEC, IEEE, SPLN, and CIGRE standards to ensure the accuracy of the analysis of the frequency response results. An approach for transformer diagnostics is discussed in this research by doing a comparative analysis with four study cases related to various physical phenomena and examining the cross-combined between standards and field FRA results. Four FRA measurement cases are taken from the experience in PLN, namely: Tayan (water contamination), Sanggau (transformers relocation), Sambas (rebuilding transformer foundation), and Cianjur (earthquake). The evaluation results indicate that the IEEE and IEC diagnostic standards have an assessment that is closest to the actual condition that is influenced by variations in wide band frequency measurement.