STORAGE EFFICIENCY OPTIMIZATION OF A SUPERCAPACITOR CHARGED BY A PHOTOVOLTAIC CELL USING GENETIC ALGORITHM

Abstract: Super capacitors are very power dense devices in which charge density depends on the value of the capacitance and voltage across it. Generally, high capacitance of the Supercapacitor would support higher energy storage density, voltage remaining fixed. The load driven also does not utilize properly the entire stored charge from the Super capacitor due to inconsistency in electrical characteristics between the load and source. Storage efficiency of Super capacitor has state of charge dependencies as it is variable over the duration of charge/discharge cycles. It depends directly on the capacitance and indirectly on the ESR value. The proposed optimization technique can significantly find the maximum value of storage efficiency at a near about minimum value of ESR and maximum value of capacitance. The simulation model and results show the advantage of the said technique.

Keywords: Supercapacitor, Photovoltaic panel, RC branch model, Energy storage system, Solar photovoltaic equation, Genetic algorithm, Storage efficiency, Perturb & Observe algorithm, Buck Converter.