Synchrophasor Measurement-based Modal Analysis in Power Grids

Abstract

Mode, mode shape, and participation factor are important modal parameters in small signal stability analysis. Most of the existing measurement-based methods focus on mode or mode shapes estimation, few of them explore the participation factors estimation. This paper proposes a multichannel modal analysis approach to estimate not only dominant modes and mode shapes, but also participation factors from synchrophasor measurements. The wavelet power spectrum is first applied to primary wavelet coefficient matrices of multichannel measurements to detect the critical scale ranges associated with the dominant modes, and new wavelet coefficient matrix with same critical scale in the detected scale ranges are constructed from the primary wavelet coefficient matrices. Applying singular value decomposition to these constructed matrices whose scales located in a range associated with one dominant mode, a maximum singular value vector is formed from each singular value matrix. Using the right and left singular value vectors of the maximum component in the formed maximum singular value vector, the dominant modes and mode shapes are all estimated. Meanwhile, the corresponding participation factors of the generators associated with the determined dominant mode are solved via the estimated mode shapes and their inverses. The proposed approach is tested and evaluated on a 16-machine 68-bus test system. The results demonstrate high accuracy and efficiency of the proposed approach in the estimation of dominant modes, mode shapes and participation factors utilizing synchrophasor measurements.