Abstract: In this paper, the dynamic performance of automatic load frequency control of three-area power system is done by using PID controller. When load changes then, there is drift in system frequency and voltage which in turn leads to loss in generation owing to blackouts and line tripping. Main objectives of automatic load frequency control in each area is to supply load demand and to minimize tie-line power deviations, to minimize transient deviations, to improve steady-state error and to match the output power of generator with change in load. Thus, simulation evaluation is done to know the working of ALFC by building simulink models in single area, two area and three area power system.
Keywords: Automatic Load frequency control, Area control error (ACE), Proportional integral derivative (PID) controller, Matlab/Simulation.