Fuzzy based intelligent frequency control strategy in standalone hybrid AC microgrid

Due to environmental concerns, there is lot of emphasis on the use of renewable energy sources as distribution generation sources for electric power generation. These distributed sources have resulted in the concept of AC/DC micro-grids. But the intermittent nature of these sources cause many control problems and thereby affect the quality of the power within a micro-grid operating in a standalone or grid connected mode. In this paper an AC micro-grid operating in standalone mode and consisting of wind turbine generators (WTGs), solar photovoltaic (PV), diesel engine generators (DEGs), fuel cells (FCs) and battery energy storage system (BESS) has been considered for simulation studies. An intelligent control technique based on fuzzy gain scheduling of the conventional proportional-integral-derivative (PID) controller is proposed for frequency regulation for sudden changes in load or generation power or both. The performance of the fuzzy gain scheduled PID (FGSPID) controller is compared with that of the conventional PID controller for comparative analysis. The simulation results demonstrate the effectiveness of the FGSPID controller in terms of less oscillations and reduced settling time and overshoot.