Region of Attraction of Power Systems

The integration of renewable energy sources in power systems requires a well-balanced control to guarantee system stability in view of fast fluctuating power injections. We present several conditions on the stability reserve of a power system in terms of the region of attraction of its steady state that can be used to design and evaluate such controllers. The power system is modeled by the coupled swing equations. The region of attraction of this nonlinear systems is determined based on Lyapunov theory and Barbalat's lemma. The resulting conditions provide both 2-norm and ∞-norm regions of attractions. The different conditions differ, e.g., in their conservatism and in the required knowledge of the power system parameters.