Load Frequency Control by using Fuzzy-PID controller with Optimized Membership Functions

Load Frequency Control (LFC) is one the most important topics in power systems. To this end, Proportional-integral (PI) controllers is usually employed in industry. In this paper, a Fuzzy-PID controller with optimized membership functions has been designed for LFC in a two-area power system. Optimization has been employed in order to define the location of input membership functions and gains of Fuzzy-PID controllers. Imperialist Competitive Algorithm (ICA) has been used for optimization in this study. Simulations have been carried out in MATLAM/SIMULINK in presence of wind power and variable loads. In order to conduct comparisons, the simulations have been carried out using the fractional order PID (FOPID) controller optimized by ICA. Moreover, to verify robustness degree of the proposed controller against system uncertainties, simulations have been done by changing the parameters of two-area system. Results of simulations illustrate good performance of the proposed controller.