Modal phase identification from WAMS data using Hilbert transform and S-transform: A comparative study

Power system oscillation mode identification and its characterization are very important in monitoring and control. In this paper, the phase and frequency information extraction procedure from Wide Area Measurements using two methods, viz Hilbert transform and S-transform methods are compared. Identification of inter area modes and their characterization is done. Synthetic as well as real time signals are used to extract the modal information. Modal frequencies are extracted from the WAMS signals recorded in the Eastern Interconnect Phasor Project (EIPP) on 20th July 2005 and is used for phase angle identification.