An approach based on µ- synthesis and analysis theory is proposed for the design of load frequency controller in response to the new technical control demand for power system in a deregulated environment. In this approach the power system is considered as a collection of separate control areas and each control area can buy electric power from some generation companies to supply the area-load. The proposed technical scenario is illustrated with application to !he design of load-frequency controller for a typical control area The resulting controller is shown to minimize the effect of disturbances and achieve acceptable frequency regulation in presence of uncertainties and load variation.
