Study of Total Selectivity Between the Benin's Distribution and Transmission Networks

Abstract

The study is based on the electrical protections installed on the Maria Gléta substation network. The study area is delimited: from the secondary of the power transformers (T2 and T3) of the Community of Benin to the 15 kV departures of the cell a Beninese electricity distribution company associated to the substation. We have verified the settings implemented in the protection relays as well as the adequacy of the selectivity applied between these relays. The objective was achieved by determining the polyphase and single-phase short-circuit currents using the ETAP software with the sole aim of evaluating the conformity of the settings made with the existing fault currents. This evaluation required the study of overload, short circuit and ground fault protection devices. The results obtained reveal that the settings made are not in accordance with the known and retained setting principle; nevertheless, the coordination between these parameters is respected. However, there is a gap in the installed protection plan and a more advanced and adapted protection has been proposed.