DYNAMIC MODEL REDUCTION FOR THE MODAL ANALYSIS OF FREQUENCY AND POWER OSCILLATIONS IN LARGE POWER SYSTEMS

In this paper a new method for the modal analysis of slow frequency and power oscillations - penetrating a whole electric power system - is presented. By this Modal Power System Analysis Method there can not only be determined the damping degree and the period duration of the dominant power system oscillation, but also the location of those power plant units which are influencing the power system oscillations essentially. Due to this fact also aimed counter actions can be derived. For being able to apply the Modal Power System Analysis Method also to large extended power systems an additional Dynamic Power System Reduction Method has been developed. By this method only those physical state variables inside of a considered subsystem are retained, which are essential for the dominant power system oscillation. As an application case the northern part of the UCPTE-network has been chosen, where a strong power system oscillation had occured some years ago.