Application of Hybrid Energy Storage System in Power Balance of Stand-Alone Photovoltaic Power System

In this paper it is proposed to apply a hybrid energy storage system consisting of lithium iron phosphate(LiFePO4) battery that is environment-friendly and possesses high energy density and super capacitance combination that possesses high power density and long service lifecycle in standalone photovoltaic(PV) power system.Taking the optimization of system reliability and operation states as the object,the control structure of the proposed hybrid energy storage system and its control modes are designed to optimize both system reliability and operation status of the energy storage devices.Simulation analysis of the proposed system is performed and analysis results show that under the fluctuation of PV cell output and pulsating load the instantaneous power can be rapidly balanced by the proposed hybrid energy storage system,thus reliable operation of the proposed system can be sustained.