Calculation of voltage sags originated in transmission systems using symmetric components

The objective of this work is the study of voltage sags presented at a particular point of an electric network, when a short circuit fault takes place in some point of the transmission system. Different types of short circuits were analyzed, so much balanced as not balanced, applied to a bar of a typical power system, and the resulting voltages were obtained in the terminals of the sensitive equipment that are connected at the point of common coupling (PCC) on another bar. The habitual techniques of symmetrical components for short-circuit analysis were used. The sensitive equipment were considered threephase, star connected with neutral. To contrast the results the power system was implemented in the program DigSilent, and the same events were simulated. Starting from the obtained results, and carrying out the appropriate simplifications, the voltage sags were classified according to the approaches mentioned by Bollen.