Simulation of Supercapacitor Charge and Discharge in Photovoltaic Applications

In this work, a simulation approach to estimate the charge and discharge profile for a supercapacitor storage application is proposed. The approach assumes the supercapacitor as a storage element in the DC bus for converter system starting from a photovoltaic source. Two synchronous step-down converters are considered for the energy transformation from the PV source towards the load. A slow dynamics model was developed and is proposed to estimate the charge and discharge voltage evolution of the supercapacitor at constant power, which is validated against numerical simulations in LTSpice environment of the system. Results show that the accuracy of the proposed model is good as it shows only minor deviances due to the dissipative elements present in the DC-DC converters.