Control of hybrid standalone power generation systems using fuzzy logic control

Abstract

Standalone photovoltaic system used mainly for the residential load tends to have issues in inconsistent power supply and voltage fluctuation. This issue inevitable due to the characteristic of most renewable power generation in producing intermittent power to the load. Energy storage system such as battery and fuel cell functions to support the system by providing compensation to the power generation system when the power generated is less than required. Numerous control strategies are implemented into photovoltaic system to control the dc-dc converter such as proportional integral derivative (PID) control, sliding mode control (SMC) method and the fuzzy logic control (FLC) technique. Fuzzy logic control is a system that are capable of regulating the voltage flow of the energy storage system by controlling the converter. This work proposes design of fuzzy logic control system for standalone photovoltaic-battery hybrid system and standalone photovoltaic-fuel cell hybrid power generation system. The photovoltaic hybrid system size is also calculated to provide load supply to the residential load in Malaysia. Fuzzy logic control system is designed to focus on the voltage regulation and stability of the DC bus. Similar to battery, fuel cell would function as the energy storage system for the hybrid system for this project. Both hybrid system is simulated using MATLAB/Simulink simulation to obtain the voltage of the DC Bus. The implementation of fuzzy logic control in the photovoltaic-battery system shows a positive result in maintaining the DC bus voltage at the reference voltage. As for the photovoltaic-fuel cell system, the implementation of fuzzy technique does not show a huge difference in regulating the voltage at DC bus.