Wide-area Damping Control Under Limited Data Feedback Condition: An Observer Driven System Copy Approach

Limited data feedback rate, e.g. 1-10 samples per second instead of 25-60, causes adverse effect on wide-area damping control (WADC). An observer driven system copy (OSC) approach is suggested here to deal with low data rates. The basic idea is to use the knowledge of nominal system dynamics to approximate the actual system behavior during intervals when data from phasor measurement units (PMUs) is not available. This is corrected whenever the most recent states are obtained from the observer at the PMU location. The closed-loop performance deteriorates as the operating condition drifts away from the nominal dynamics. Nonetheless, significantly better performance compared to conventional feedback (CF) is obtained under low feedback data rate condition. The deterioration in performance is quantified in terms of the difference between the nominal and off-nominal dynamics.