Management and control of the integration of supercapacitor in photovoltaic energy storage

Standalone operation of a photovoltaic energy generating system under solar irradiance fluctuation and variable temperature is a difficult task. Thereby, it's necessary to implement an energy storage system. Among the energy storage devices, the battery is a promising solution that has higher energy storage density, but the inconvenience is the low power density and limited charge/discharge cycles. The supercapacitor guarantees a long cycle life and has a large range of operating temperatures, but suffers from a low energy density and high cost. Combining the two storage devices is possible to obtain good compromise in terms of energy density and a long cycle life. This paper, present a hybrid energy storage with a photovoltaic energy source, that consists of a combination of battery and supercapacitor, where both are connected to the DC bus. An energy management strategy is proposed for the hybrid energy storage with a view to improve the performance of the battery storage. The simulation result has been conducted to verify the effectiveness of the integration of supercapacitor in the photovoltaic energy storage. However, the obtained results of the comparison of photovoltaic energy storage without supercapacitor and with supercapacitor prove that the electrical stresses on the battery are reduced by introducing the supercapacitors.