Power System Oscillatory Behaviors: Sources, Characteristics, & Analyses

This document is intended to provide a broad overview of the sources, characteristics, and analyses of natural and forced oscillatory behaviors in power systems. These aspects are necessarily linked. Oscillations appear in measurements with distinguishing characteristics derived from the oscillation’s source. These characteristics determine which analysis methods can be appropriately applied, and the results from these analyses can only be interpreted correctly with an understanding of the oscillation’s origin. To describe oscillations both at their source within a physical power system and within measurements, a perspective from the boundary between power system and signal processing theory has been adopted. The power system is viewed as a generic system of inputs and outputs without emphasizing swing equations, generator models, etc. Similarly, the analysis methods used in examples have been selected to represent multiple broad classes, rather than to emphasize the performance of specific methods.