The analysis of power quality effects from the transformer inrush current: A case study of the Jeju power system, Korea

The transformer inrush current can cause a voltage drop by source impedance. This current can impact sensitive loads by the voltage drop. Therefore, it is necessary to take measures to limit this inrush current. Accurate modeling and analysis for inrush current is the first step in developing a technique to take practical measures. This study, described in this paper, analyzes the power quality affected by transformer inrush current using the Jeju power system in Korea. The Electromagnetic Transients Program (EMTP) is used to analyze the transient phenomenon. We discuss a method to model the hysteresis curve of the transformer in EMTP. We carried out various simulations to analyze the power quality during transformer energization. The analysis results of voltage drop by the inrush current occurrence when certain requirements are met are presented.