Improving Matrix Pencil and Hankel Total Least Squares algorithms for identifying dominant oscillations in power systems

Matrix Pencil (MP) and Hankel Total Least Squares (HTLS) algorithms approximate an input signal as a sum of decaying sinusoidal oscillations. This paper presents a simple technique to improve these algorithms for extracting only the true oscillations present in the input signal. The rationale behind the improvement is the observation that the true modes present in the input signal appear consistently irrespective of the order of the linear approximation used in MP and HTLS algorithms. It is shown that the modes appearing consistently can be extracted using a sorting method. The improved MP and HTLS algorithms presented in this paper are used for monitoring the low-frequency oscillations in power system in an online environment. The performances of the proposed algorithms are demonstrated using synthetic signals and simulated signals of different test systems.