EFFECT OF CORE CUTTING TOPOLOGY AND MATERIAL OF THREE PHASE TRANSFORMER ON MAGNETIZATION CURVE AND INRUSH CURRENT: EXPERIMENTAL APPROACH

Abstract

This study conducts the core cutting topology effect in three phase transformer on magnetization curve and inrush current. Core cutting topology effect on magnetization curve and magnetic field is analyzed using Finite-Element Method (FEM) simulation at the points of connection between the core pieces. The magnetization curves are used to determine inrush current of each transformer. Therefore, calculated inrush current was then compared to experimental measurements of inrush currents. The existence of residual flux or remnant flux is considered in inrush current measurement, thus demagnetization method is used to obtain the real inrush current value. Simulation and experimental results show that the topology of the transformer core cutting affects the magnetization curves and inrush currents. These are proven by differences in the magnetization curve and inrush current of both topology transformer core cutting. It was also suggested that quality of core material affected the magnetization curve and inrush current.