Inrush Current Influence on the Hysteresis Loop of a Single-Phase Transformer

The inrush currents which generated at the energization moment of an electric transformer can reach high values and cause some abnormal problems in the power system. The idea of this article is original, and represents an initiation to a research project to visualize the effect of transient regimes on the characteristics of the iron core. The main purpose of this paper is to treat the influence of this transient phenomenon, i.e. inrush current, on the hysteresis loop of single-phase transformer, either in terms of its size, area, or position. First, a general study of the electromagnetic characteristics of the transformer iron core will be presented. Then, using the ATP_EMTP program, the simulation is realized to visualize the relationship between the hysteresis loop and the magnetizing inrush current in the transient state. Finally, the results show the decrease of the hysteresis loop area and their shift with respect to the origin of the axes following the increase in the transient inrush current peak.