Combining Trajectory Data with Analytical Lyapunov Functions for Improved Region of Attraction Estimation

Abstract

The increasing penetration of inverter based sources (IBS) has been raising a lot of concerns for the power system system operators around the world. The high level of complexity of this kind of generators make model-based stability analysis a difficult task for operators. This work presents a method to estimate the Region of Attraction (ROA) based on sychrophasor measurements, through trajectory polynomial fitting using Bernstein polynomials, of a converse Lyapunov function of the system and its derivative. The method is derived from the expansion of a previous ROA, which guarantees an inner approximation and is not dependent on the chosen approximation method, in this case the Bernstein polynomials. The mathematical derivation is described and applied to the Single Machine Infinite Bus (SMIB) system.