Avaliação da influência das forças eletromagnéticas nos entreferros de transformadores de corrente de proteção.

Abstract

The evaluation of the influence of electromagnetic forces in the gaps of protective current transformers is presented in this work. The evaluation is developed from the verification of the transient response of protective current transformers, considering the displacements in the gaps caused by the electromagnetic forces. Therefore, it was evaluated the influence of the electromagnetic forces for protective current transformers with 8 mm, 16 mm and 24 mm gap length, and then, with different gap distributions in the core. The development of computational simulations based on the Finite Element Method, made it possible to determine the electromagnetic forces and the displacements in the gaps. According to the results obtained in this research, it was concluded that the electromagnetic forces acting on the protective current transformer gaps, under conditions of permanent regime and short circuit, do not influence the current transformer response for any of the cases evaluated.