Damping of power system oscillations by use of controllable components

This paper deals with damping of power system electromechanical oscillations using controllable series compensators (series capacitors and phase shifters) and controllable shunt capacitors. The study is based on investigation of the eigenvalues of a simple linearized power system model. The controllable series components are located on the transmission line connecting two areas and the controllable shunt capacitor is located close to a load. It is shown that the level of transmission line loading, load characteristics and inertia of the two areas influence the damping achieved by the controllable components to different degrees. The contributions of the controllable series components to the enhancement of power system damping for the same rating of the controllable components are compared. Numerical examples are provided to verify the theoretical findings. The purpose of this paper is to provide an insight and understandings in the basic characteristics of the damping effects of the studied devices. This insight is obtained by study of a simple power system that exhibits power oscillations. The understandings and findings can facilitate the analysis of realistic, and more complex power systems.>