Transformador de corrente com núcleo toroidal para recuperação de energia eletromagnética.

Abstract

In this work an analytic and computational analysis of current transformers (CT) with soft magnetic material toroidal core used as energy harvester is presented. The theoretical approach is based on the fundamental laws of electromagnetism presented in Maxwell's equations. Magnetomotive forces, reluctance and magnetic flux were taken into account in order to obtain equivalent magnetic circuits. Using a 2D simulation tool based on finite element method, computational simulations were performed in order obtain the distribution of magnetic induction in radial direction of the toroidal core. As predicted by the analytical expressions, the magnetic induction is distributed nonuniformly in the radial direction of the core. Based on the magnetic circuits, equivalent electrical circuits were deducted, in which the resistance and reactance were represented. Based on computational simulations, it was possible to conclude that the efficiency of the TC as energy harvester varies according to the core material, to the load at its secondary terminal, to the coupling coefficient between primary and secondary and to the existence of air gap in the magnetic core.