Loop exploration of the high voltage (60 kV) network of EDP Distribuicao

This document describes the challenges and issues related to the operation of a distribution network in a loop configuration. The loop is fed from three different injection points (Valdigeni Pocinho e Chaves) through the high voltage (60 kV) electrical network of EDP - Distribuicao. The profits of this new philosophy of exploring the electrical network are quantified. They are due to the decrease of Joule losses, the increase of system stability and the quality of the service provided. Crucial in this process will be the correct and selective setting of the protection system; its complexity is increased with the demands of the process and the high concentration of independent power producers in the system. The possibility of occurrence of system splits and unexpected connections to the grid by independent producers forced the installation of synchronism checking systems to assure a safe and continuous exploration of the loop. This also allows for the emergence in the near future of additional independent production. It will also stabilise system voltages, which is an important advantage with respect to the normal electrical feed due to a lower sensitivity to unexpected connections by the independent producers