Monitoring and Reporting of Security of Power System Low-frequency Oscillations

Abstract

This article deals with the monitoring and visualization of security of power system oscillation modes. The monitoring is performed by means of a performance index based on the traditional stability measure, but it reports on relative changes in the system low-frequency characteristics in a more indicative manner. In addition to introducing a dramatic progression at marginal changes in the mode's characteristics, the index also communicates the “relative distance” to the dangerous system stages by reporting the available security margin. Using the index, system states can be meaningfully visualized. In this article, the matrix visualization technique is applied for that purpose. The technique sufficiently facilitates human interaction for identification of the system states under different network and operating conditions.