Power System Oscillations
Chapter 7: Power System Stabilizers
Abstract
Power system stabilizers have been used for many years to add damping to electromechanical oscillations. Essentially, they act through the generator’s excitation system in such a way that a component of electrical torque proportional to speed change is generated (an addition to the damping torque). Of course, it is easy to say that this is done, and the mechanism varies depending on whether the mode is a local mode or an inter-area mode. Nevertheless, an effective stabilizer does produce a damping torque over a wide range of input frequencies. Less effective stabilizers may only produce a damping torque over a very small frequency range. This leads to problems when system changes cause the system’s oscillatory modes to change.
