Influence of power transformer winding connections on the propagation of voltage sags through electric system

This paper addresses several important issues for reliable assessment of the number of voltage sags in modern distribution systems. Depending on the conditions of the network voltage sags propagate differently and affect different areas of the network. The analysis has been carried out to assess the influence of network topology on voltage sag propagation. The purpose of this paper is to analyze the influence of all types of connections transformers on the propagation of voltage sags on electrical system. The study shows that some transformer winding connections like Yd have more significant influence than any other type of winding connection. For analyzes the phenomenon, it was modeled on the ATP - alternative transient program - a standard IEEE 14-bus system and a sags generator, which is able to generate any kind of voltage sag with any variations of the magnitude and phase angle. With mathematical formulations based on balanced and unbalanced circuits theories.