Design of load frequency controller for power system subject to bounded persistent disturbances

The waveforms of the electric power generated from renewable energy sources such as wind and sunlight are known to be uncertain and, very often, vary persistently for a long period of time. This thesis presents the design of load frequency controllers for power systems that are subject to persistent disturbances by using the principle of inequalities and the principle of matching. The principal design objective is to guarantee that the magnitudes of the outputs of interest always stay strictly within their acceptable bounds for all time in the presence of all the possible disturbances. An advantage of the framework adopted here is that once a solution is found, the system is guaranteed to operate with satisfactory levels of security and quality supply. Two case studies have been carried out; the numerical results clearly show that the framework adopted here is suitable and effective, thereby giving a realistic formulation of the design problem.