Modeling of Transformer Windings for Fast Transient Studies: Experimental Validation and Performance Comparison

Fast front pulses from lightning and switching conditions produce transient overvoltages and dielectric stresses that can result in premature deterioration or failure of transformer windings. Predicting these conditions in new transformer designs requires the implementation of internal winding models. This paper analyzes the accuracy and performance of different transformer winding models available in the literature, by means of comparisons with time- and frequency-domain measurements on a 2000-turns disk-type winding prototype, as well as evaluation of the computer time needed by each model to perform the corresponding simulation of the same prototype. The results show that including the frequency dependence of the model parameters is a decisive factor to accurately reproduce the measurements. They also show that a lumped parameter model described in a turn-by-turn basis can provide accurate results and requires shorter simulation time than a distributed parameter model.