This paper examines the Fractional order PID (FOPID)controller of Automatic Load Frequency Control (ALFC) for three area interrelated power system is designed and analyzed with two steam turbines and one hydro turbine. In any area of the interconnected power system if there is alteration in load demand, it will affect the performance of the system. The frequency and tie-line power also deviate. In order to lessen the frequency and tie-line power deviation, system should be provided by introducing traditional controllers such as I, PI, PID and Artificial Intelligence technique like Artificial Neural Network (ANN).

Keywords : Load Frequency Control, Fractional Order PID Controller, Frequency Deviation, Interconnected Power System.