Robust, adaptive or nonlinear control for modern power systems

Major objectives in power system control design include regulation of voltages and frequency, adequate damping of oscillations and preservation of synchronism in the face of large disturbances. These objectives must be met in the face of changing operating conditions some of which may not be anticipated a priori. Further, modern operating schemes will enhance the level of uncertainty. It is unlikely that traditional off-line tuning of simple decentralised controllers will be adequate. This paper looks at what some modern control tools have to offer in the power systems context. In particular, we review robust, adaptive and nonlinear control and their possible combinations. Their applicability to various classes of power system control problem is considered. In particular, the type of modelling uncertainty (structured or unstructured) and type of disturbance (small or large) is important. In system theoretic terms there seems to be many opportunities for further use of centralised (and decentralized) nonlinear control