Semianalytic Solution for a Simple Model of Inrush Currents in Transformers

Abstract

This paper presents a proposal of a semianalytic solution for the system of differential equations that governs the behavior of a power transformer under energization. The presented model takes into account nonlinearity due to magnetization curve. The proposed approach for the solution uses recursive expressions, applied to the description of the transformer inrush current. The inrush current in a 120-VA small transformer is simulated and the results of the proposed method agree with the values obtained experimentally.