Estimation and computation of transfer function parameters from FRA data for analyzing transformer winding deformation and displacements

In this paper, experimental investigation carried out on a transformer to obtain frequency response data under various deformation/displacements physically simulated to study and identify the various parameters that influence the frequency responses is presented. Transfer Function using real-rational polynomial function model was computed from the Frequency Response Analysis data. Various transfer function parameters were computed for reference and simulated faulty Frequency Response Analysis data. These parameters are then analyzed to relate changes to characterize the defects by correlating with type and position of the deformation/displacement. The analysis presented based on the transfer function characteristic parameter changes will help in diagnosing transformer winding deformations/displacements.