An approach based on structured singular value theory is proposed for the design of robust load frequency controller in response to the new technical control demand for large scale power systems in a deregulated environment. In this approach the power system is considered under the pluralistic Load Frequency Control (LFC) scheme, as a collection of different control areas. Each control area can buy electric power from some generation companies to supply the area-load. The control area is responsible to perform its own LFC by buying enough power from pre-specified generation companies, which equipped with robust load frequency controller. A three area power system example is given to illustrate the proposed approach. The resulting controllers are shown to minimize the effect of disturbances and achieve acceptable frequency regulation in presence of uncertainties and load variation
