Frequency Response Analysis Interpretation for Winding Deformation of Power Transformers

This chapter presents an overview of the Frequency Response Analysis (FRA) technique, which is a diagnostic tool used primarily for identifying mechanical deformation of transformer windings and core. It further introduces international standards for FRA measurements and their interpretation schemes. The main standards on FRA interpretations are: The Electric Power Industry Standard of People's Republic of China (2005), CIGRE Technical Brochure 342, IEC 60076‐18, and IEEE Std. C57.149 (2013). Certain schemes have been practiced widely by utilities, while other schemes are proposed in the literature by researchers. Three case studies are presented, which use several schemes available to analyze the response. Finally, the chapter discusses non‐mechanical factors which are influential on FRA measurement. Although these factors are not the main focus in analyzing the response, it is interesting to understand how the factors could affect the measurement.