Accurate Supercapacitor Modeling for Energy Harvesting Wireless Sensor Nodes

Supercapacitors are often used in energy harvesting wireless sensor nodes (EH-WSNs) to store harvested energy. Until now, research into the use of supercapacitors in EH-WSNs has considered them to be ideal or oversimplified, with non-ideal behavior attributed to substantial leakage currents. In this brief, we show that observations previously attributed to leakage are predominantly due to redistribution of charge inside the supercapacitor. We confirm this hypothesis through the development of a circuit-based model, which accurately represents non-ideal behavior. The model correlates well with practical validations representing the operation of an EH-WSN and allows behavior to be simulated over long periods.