Analytical Model for Supercapacitor Sizing as Part of a Hybrid Power Supply

Abstract

The paper analyzes the a specific way to size a supercapacitor as a part of a hybrid energy power supply. Defining the load of the power supply by its power over time requirements and using some approximations (combination of linear and constant segments only for the power profile of the load) allows the circuit to be analytically solved and expressions found for the capacitor′s voltage and current over time. These analytical results can be used to choose the supercapacitor size by postulating only its initial and final voltage depending on the segment. The approach used allows for sizing the supercapacitor for wide variety of applications by only requiring the power demand of the load to be known. The model is verified by means of simulation and experimental results.