Load Frequency Control in multi-area power system based on Fuzzy Logic-PID Controller

In an interconnected multi-area power system, as a power load demand varies randomly, in the case of any small sudden load change in any of the areas, both area frequency and tie-line power flow interchange also vary. The main goals of Load Frequency Control (LFC) are, to hold the frequency and the desired power output in the interconnected power system at the scheduled values and to control the change in the tie-line power flow between control areas. The purpose of this paper is to present basically an application of Fuzzy Logic Controller (FLC) based load frequency control using PID controller in multi-area interconnected power system. The fuzzy logic is employed to search for optimal values for the PID controller parameters. The three-area 9-unit model system is used for the simulation, and the transient responses are shown due to step load disturbances in area-1, area-2 and area-3. The main primary objective is to suppress all the fluctuation of the system frequency and tie-line power flow. By comparison to the conventional Ziegler-Nichols technique (Z-N) and to the heuristic Particle Swarm Optimization method (PSO), the effectiveness of the proposed method is confirmed.