Analysis of asymmetric magnetization current and reactive power demand of power transformers due to GIC

Abstract

A comprehensive analysis of the asymmetric magnetization current of single phase power transformers due to geomagnetically induced currents, GICs, is presented in this paper. The aim of this work is to understand the main characteristic of this magnetization current such as peak current and harmonic contents. Usually, computation of the magnetization waveform requires a transient analysis in FEM or EMTP software. Also, the characteristic of the transformer and network parameters are demanded. We introduced a simple and accurate formula for estimation of the main characteristic of the magnetization current. Only general information of the transformer and the network is enough for this estimation. According to the result of this work, also a method for prediction of the reactive power demand is presented.The achievements of this paper are useful for designers of transformers in the calculation of losses due to GICs. Furthermore, the grid owners can have a good prediction of increasing reactive power demands and injected harmonics to the network due to a GIC event.