Propagation of Voltage Sags: Influence of Transformers, Induction Motors and Fault Resistance

This article presents the analysis of the propagation of voltage sags. The ATPDraw tool is selected for simulation of the IEEE 34 Node Test Feeder. It takes into account both voltage sags caused by electrical fault network, as well as the propagation characteristics of voltage sags caused by induction motor starting and transformer energizing. The analysis has been carried out to assess the influence of the transformers winding connections, the impedances of these transformers, lines and cables, summarizing the effects on the magnitude and phase of the disturbance. The study shows that the influence of the induction motor in the propagation of voltage sags resulting in an increase in the severity of the voltage sag. Voltage sags caused by induction motor starting and transformer energizing not have zero-sequence component, so they are only affected by transformers-type 3. It was found the influence of fault resistance on the characteristics of magnitude and phase of voltage sags and identifies some aspects of interest in the characterizations of these electromagnetic disturbances.