Load Insertion Influence on the Hysteresis Loop of a Single-Phase Transformer under Transients

The hysteresis cycle is one of the main parameters that define the characteristics of materials used in the design of transformer. This parameter is strongly influenced by the transient regime of the transformer which has a great influence on the operating point of the transformer. The idea of this paper is original and represents an initiation to a research project aimed at visualizing the effect of load insertion on the characteristics (hysteresis loop) of the iron core. The main objective of this article is to address the influence of this load on the hysteresis loop of a single-phase transformer in transient mode, i.e. in inrush current, in terms of position, surface or size. 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 performed to visualize the relationship between the hysteresis loop and the load insertion on the secondary side of the transformer in transient mode. Finally, the results show the decrease in the surface of the hysteresis loop and their shift from the origin of the axes following the increase in the load.