Comparing the approaches to the measurements-based express-analysis of low-frequency oscillations in power systems

Modem measurement systems being implemented in power systems worldwide provide the unprecedented possibilities of analyzing the electromechanical transients and especially the oscillatory processes. As the communication and data processing technologies are being advanced at a quick pace, the possibilities of detecting and characterizing the low-frequency oscillations, which may threaten the power system stability and reliability, grow even wider. The two methods of timely detecting the oscillatory components have been developed on the basis of the approaches commonly utilized for solving the relevant tasks - the discrete Fourier transform and the Prony transform. The basic features of the methods are described and they are compared in terms of results quality and speed of operation for subsequent on-line application.