Control of electric power systems

Abstract

The increase in size and complexity of interconnected electric power systems, coupled with the industrial commitment to maximize security at a minimum cost, has led to the development of many special control devices. These control devices ensure that the electric power system is able to operate, without instability, under a wide range of system conditions. This article presents a tutorial overview of the basic concepts and techniques of control for stability in electric power systems. Emphasis is placed on the robustness of the overall electric power system along with modifications to the basic control necessary to achieve this robustness. Different stability concepts are illustrated and the associated stabilizing mechanisms and equipment are described. To facilitate the implementation of the stability criteria, models of power system components are described. Special considerations are then given to the tuning of the automatic voltage regulators and the associated analytical tools for steady-state regulation as well as small- and large-signal performance. Next, the issue of automatic generation control is critically examined before an efficient system-wide control scheme is presented. This scheme gurantees power system stability against any disturbance occuring anywhere in the power network. Some important topics like control during restoration, overvoltage control, new concepts in interconnected power system control, coordinated voltage control and artificial neural networks in power systems are discussed.