Swept Frequency Response Analysis (SFRA) – An efficient tool for transformer winding distortion – A case study on power grid transformers at Delhi

High short circuit currents can lead to deformations and displacements of the transformer windings due to mechanical forces. The paper discusses Swept Frequency Response Analysis (SFRA) - a modem diagnostic method which identifies such pre-damaged power transformers which has better sensitivity towards changes in the winding geometry. Changes in the geometric configuration alter the impedance network, and in tum alter the transfer function. This enables a wide range of failure modes to be identified.