Locating mechanical deformations in electromagnetic model of transformer winding

This paper presents a diagnostic method for locating and assessing the severity of mechanical deformations in an electromagnetic model of transformer winding. The proposed method involves performing frequency response analysis on the model and capturing its high frequency behaviour through terminal measurement. The terminal quantities are natural frequencies, magnitude and phase of impedance, neutral current, dc resistance, equivalent inductance and capacitance. Utilizing these data and performing constrained-optimization, a physically realizable, electrically and magnetically coupled ladder network pertaining to healthy model is synthesized. Then, mechanical deformations in model are introduced by producing discrete changes in capacitances. Once again synthesizing ladder network is achieved corresponding to faulty state of the electromagnetic model. Comparing the elements of those synthesized circuits will identify the fault location together with its severity. The electromagnetic model is capable of producing high frequency behaviour of winding. Hence, applicability of the proposed method to the transformer winding is feasible.