Forced Oscillations in Power Systems (TR 110)

Forced oscillation is a phenomenon where the power swing is caused by an external periodic input, e.g., an oscillating steam valve in a turbine generator. The phenomenon has been known for years; however, only become more visible recently, thanks to the installation of Phasor Measurement Units (PMUs). This technical report is driven by the forced oscillation incidents reported across the globe and tries to cover the following three topics: 1. Demonstrate forced oscillations through examples, 2. Formulate forced oscillations, and 3. Provide means to distinguish forced from natural oscillations.