Interpretation of Frequency Response Analysis for Fault Detection in Power Transformers

Frequency response analysis (FRA) is a method of monitoring power transformer’s mechanical integrity. However, identifying the type fault and its severity by comparing measured responses still challenging mostly relies on personnel expertise. This paper taking one step forward to standardize FRA interpretation process proposing guidelines based various international standards case studies. In this study, signature divided into three regions: low-, mid- high-frequency regions. The deviation from fingerprint for faults classified small, large, no variations, calculation correlation coefficient. proposed are developed frequency regions, level variation represented using simple arrow simplify process. A study conducted three-phase 11/0.433 kV, 500 kVA distribution transformer with short circuit winding validate guidelines.