A pilot project for the survey of sag performance of the Brazilian transmission system

Considering the ample institutional experience in Brazil, ONS, the exclusive Brazilian ISO-Independent System Operator has been working diligently to bring into force all previous concerns with respect to power quality. To this end, regarding voltage sags and swells, it has been observed that the amount of information available in Brazil at this time was not enough to permit solid conclusions to be safely made. For that reason, a special measurement survey pilot project has been initiated. This project has as one of its prime objectives the identification of the main causes and mechanisms regarding the propagation of sags and swells occurring in the Brazilian transmission system, as well as to subsidize the definition and characterization of the phenomenon and its indices. The partial results obtained so far are presented in this paper.