Analysis of Power System Oscillations From PMU Data Using an EPLL-Based Approach.

Recently, the application of the adaptive notch filter (ANF) concept to the analysis of damped oscillations and the estimation of frequency and damping factor of such oscillations was introduced. This paper presents the application of the enhanced phase-locked loop (EPLL) to the same problem. A modified version of the EPLL is developed that includes the estimation of damping factor in addition to the already estimated variables of amplitude, phase angle, and frequency. The structure, mathematical formulation, and theoretical stability analysis of the proposed method, including guidelines for its parameter tuning, are presented. Simulation results verify the analytical derivations and the desirable performance of the proposed method. This paper concludes that the EPLL-based approach can address the problem as efficient as the ANF approach while offering more robust and accurate results at low sampling rate applications. [ABSTRACT FROM AUTHOR]