Estudo de modelos de transformadores para altas frequências

Abstract

This work presents a methodology for determining a mathematical model for transformers, suitable for studies of transient phenomena, whose predominant frequencies typically lie in the range of kHz to MHz. The methodology presented is based on a small single-phase transformer, although it can be extended to three-phase transformers of any power. The model is derived from measuring the frequency response of the transformer, which is adjusted by transfer functions, using, for this, the routine Vector Fitting. From the approximate functions, an equivalent network is synthesized. However, to guarantee stability in numerical simulations, the network generated is evaluated for its passivity. Finally, to validate the model, simulations are carried out in ATP with subsequent comparison with the measurement results, considering the transformer fed by sine waves and square