Discriminating changes introduced in the model for the winding of a transformer based on measurements

A systematic procedure is evolved that enables identification of the type-of-changes introduced in the model winding of a transformer, based on a comparison of measured neutral or line current and transfer-function with those corresponding to the reference case. Further, it was also possible to ascertain, whether the pertinent circuit element viz. series capacitance, shunt capacitance and self-inductance has increased or decreased (compared to initial value). The proposal was formulated based on analytical calculation and circuit simulation. Thereafter, the approach was experimentally verified using two model windings, and the results were found to be encouraging. Thus, it demonstrates one possible way, how interpretation of monitored data can lead to meaningful inferences.