Analysis of Wide-Area Input Signals for Damping Interarea Oscillation of the Interconnected Paraguayan-Argentinean System

In this work, the geometric and residues methods are applied to select the most effective wide-area input signal to damp the interarea oscillation of the Paraguay-Argentinean interconnected equivalent system for two load conditions. This oscillation mode is composed of the Itaipu, Acaray and Yacyreta generators swinging against the Argentinean system. The damping is achieved by a STATCOM equipped with a supplementary damping controller close to the load center of the Paraguayan system. Wide-area signals of transmission line active power flow and current, and voltage phase angle difference between buses from phasor measurement units are evaluated as candidates. The results showed that the two selection methods lead to different signals according to the loading condition. The effectiveness of the selected input signal is confirmed by smallsignal analysis and a large disturbance simulation using the input signal that presents high values for both loading conditions.