Real-time monitoring of steady-state and oscillatory stability phenomena in the Ecuadorian power system

The emerging synchronized phasor measurement technology has allowed the development of novel methodologies to monitor the power system steady-state angle and voltage stability, as well as oscillatory stability, in real time. In this connection, the Ecuadorian ISO, CENACE, has installed a Wide Area Monitoring System (WAMS) in order to monitor this kind of stability phenomena. One of the main challenges of real-time monitoring is to determine adequate early-warning indicators. Thus, this paper presents three methodologies for determining adequate thresholds regarding: i) phase angle difference, ii) voltage profile power transfer of transmission corridors, and iii) oscillatory issues. These limits are the referential framework for assessing stability in real time, and constitute indicators that give the operators real-time early-warning signals in case of possible risk of system stress conditions.