Prediction of transformer winding displacement from frequency response characteristics

The failures caused by short circuits are one of the causes of transformer outages. The short circuit currents induce excessive forces in the transformer windings which result in winding deformations affecting the mechanical and electrical characteristics of the winding. In the present work, a 722VA transformer winding is considered for the short circuit force and displacement analyses. The winding is subjected to short circuit current and the respective displacement of the winding is simulated and compared with the measurement. By using Finite element analysis, change in equivalent circuit parameters due to displacement is calculated and corresponding change in sweep frequency response is measured using SFRA. An attempt has been made to predict the displacement profile from change in resonant frequency in case of displaced conditions.