Estimation of physical transformer parameters from frequency response analysis

The wideband frequency response of a power transformer will yield a signature unique to its mechanical geometry. A change in the frequency response can be indicative of winding deformation. Frequency Response Analysis (FRA) is a diagnostic tool used to monitor frequency response changes. The aim of this paper is to facilitate FRA interpretation through the development of a three phase transformer model that is based on the estimation of physical parameters. The paper will demonstrate the applicability of the model by using FRA data sets of a 1.3 MVA distribution transformer and assessing the accuracy of key parameter estimates.