Abstract: This paper investigate the output power against load demand in a system having distributed generation (DG) resources connected to the existing conventional power system. So an approach has been undertaken for investigating the Load Frequency Control (LFC) problem is presented considering a widely used two area interconnected power system with distributed generation (DG) connected in area-1. In this article, a Differential Evolution (DE) algorithm has been proposed for optimizing the gains of Proportional Integral Derivative (PID) controller . The corresponding performance index of the system can be calculated in terms of Integral Time multiply Absolute Error (ITAE) and settling time (Ts). Finally, the robustness of the PID controller over the PI controller is thoroughly demonstrated in the below hybrid power systems with different conditions of load disturbances, wind power and parameter variations. it's observed that the proposed controller are robust and ensures satisfactory system performance in presence variation in system parameters and operating load conditions.

Keywords: Load Frequency Control (LFC); Proportional Integral Derivative (PID); Differential Evolution (DE) algorithm; Integral Time multiply Absolute Error (ITAE); Thermal power system (TPS); Wind Turbine Generators (WTGs); Diesel engine generators (DEGs); Fuel Cells (FCs); Aqua-Electrolyzer (AE); Battery Energy Storage System (BESS).