Abstract

This thesis is concerned with the development of a supplementary controller associated with a Static Var Compensator for damping of low-frequency oscillations (0.05-2.0 Hz) which are normally present in power systems. The objective of this thesis is to demonstrate that with the use of load modulation, damping of intermachine and system oscillation can be increased. The development of supplementary controllers requires that a simplified model of the system be available. In large systems this can be a difficult process. In this thesis a simplified approach is presented. It is based on fast fourier transform analysis of the response of the system in time domain from which a reduced order transfer function is determined. This analysis is carried out on a system similar to that of Hydro-Quebec. Classical control system design methods (root locus and bode plot) are then used to design the controller, limiting the analysis to the linear region. The extent of this region is defined in the thesis. The design of this controller is carried out and its effectiveness demonstrated in the environment of Matrix$\sb{\rm x},$ a mathematical software package. It is then confirmed for the detailed system using in-house transient stability program. The simulation results show the effectiveness of these controllers to damp the oscillations with the use of locally available variables. It is also shown that these controllers can be used to damp out the oscillations which may not be locally observable on the bus but are made available through the use of remote communication