Dynamic Analysis of a Supercapacitor DC-Link in Photovoltaic Conversion Applications

In this work, a dynamic analysis describing the charge and discharge process of a supercapacitor for the DC-link between a photovoltaic source and a constant power load is presented. The analysis results in a complete nonlinear and dynamic model that can be used for simulation and control for DC-DC converters, achieving fast recharge times and accurate steady-state voltages in the DC link to avoid overcharging the supercapacitor during low power absorption scenarios. The proposed approach includes parasitic elements for the supercapacitor and efficiency effects on the conversion stage, proposing equations useful for design and control. Stability is also discussed for the charge process of the supercapacitor. Validation of the analytical model is performed by comparison with LTSpice simulation, confirming a good agreement between theory and simulation.

Automated summary

This work presents a dynamic analysis of the charge and discharge process of a supercapacitor in the DC-link between a photovoltaic source and a constant power load. The analysis results in a complete nonlinear and dynamic model that can be used for simulation and control of DC-DC converters. The proposed approach includes parasitic elements and efficiency effects, providing equations for design and control. The analytical model is validated through comparison with LTSpice simulation, showing good agreement between theory and simulation.