Hadi Zibandeh - Mazandaran Regional Electric Company Sari , Iran

Active power needs to be generated when needed, and as power consumption varies at different times of the day, the power output of generators must also be controlled. The output power of a generator is controlled by changing its input mechanical power. The frequency deviation from its nominal value is selected as a signal to stimulate the automatic control system. In this paper, a robust controller based on Riccati s relation is proposed for load-frequency control of power systems. The proposed LFC is simple and effective and can assure that the overall system is stable for all uncertainties in the presence of generation rate constraint (GRC). An introduction to load-frequency control and the topic of variable-structure systems for LFC design is discussed first. Then the model of the power plant and its related terms are expressed. The first step in analyzing and designing a control system is to provide a suitable mathematical model for the system. The next part is the controller design. For any control system, stability is usually the most important thing to determine. The simulation results are then presented in the MATLAB / SIMULINK environment. Finally, conclusions and suggestions are presented.

Load-Frequency control (LFC), generation rate constraint (GRC), robust control, power plant