Linear Estimation of Low-Frequency Modal Oscillations Parameters Through Nonlinear Characterization

This letter proposes a technique for estimating the damping ratio and frequency of oscillatory modes with high accuracy. Traditional linear techniques such as the Prony Analysis (PA), matrix pencil (MP) method, and Eigensystem realization algorithms (ERAs) are used to accurately estimate the damping ratio and damped frequency of the oscillatory modes through a window selection algorithm. The letter ensures the best damped (positive or negative) sinusoid representation of the modal components of the oscillatory power signals observed by the phasor measurement unit (PMU) through the consensus of traditional linear techniques applied to various scenarios from Kundur two-area system, ISO-NE, and WECC 179 bus system.