O Impacto da Temperatura nas Perdas de Transformadores de Núcleo Toroidal

Abstract

This work explores the influence of temperature on optimizing losses in toroidal transformers. The aim is to develop a model to analyze the behavior of losses caused by Foucault currents and ferromagnetic material hysteresis as a function of temperature. To model this temperature effect on the iron core, the Jiles-Atherton method dependent on temperature was employed. This method was implemented in Simulink® to investigate two transformer models: a transformer considering exclusively losses attributed to Foucault currents, and a practical transformer that incorporates all losses (Foucault currents and the hysteresis curve of the core dependent on temperature). The results revealed a decrease in losses within the iron core, attributed to both eddy currents and hysteresis curves, as temperatures increase. However, the loss due to the Joule effect in the conductors increases proportionally with temperature and exceeds the losses in the core by a considerable margin. This analysis is crucial for countries like Brazil, where transformers often operate above the nominal operating temperature.