Identification and Detection of Low-Frequency Oscillation Sources Based on Synchronized Phasor Measurements

Monitoring the oscillatory stability of power systems is among the most promising applications of the synchronized phasor measurement (SPM) technology. The presence of high-amplitude low-frequency oscillations (LFOs) and the associated synchronous swings adversely affect the operation of power plant generators and can lead to an emergency operating mode of the power system. The article provides a brief overview of existing methods for identifying oscillatory phenomena in power systems and examines the most common methods for locating LFO sources. The reasons for the insufficient sensitivity of these methods are analyzed, and several improvements are proposed, including enhanced identification of LFOs, the use of data array on retrospective SPM to reveal the dynamics of oscillatory processes, and the inclusion of additional parameters in recognizing the oscillation sources. This, in turn, requires further development of the SPM theory in regard of analyzing synchronized phasors (synchrophasors) of electromechanical transients. In the study of electromechanical transients using the proposed analysis methods, additional parameters for recognizing LFO sources are identified. The advantages of using a data array on low-frequency current mode phasors for obtaining information about the propagation of oscillations in the power system are substantiated. Methods for visualizing the raw data and LFO analysis results are proposed. The architecture of a computerized system being developed for analyzing SPM data streams is presented. Tools for testing LFO analysis software have been developed, including those from the viewpoint of synthesizing data on large-scale oscillatory processes. This article summarizes and expands the previous studies of the authors related to identifying and locating LFO sources in the power system.