Estimation of the dynamic leakage current of a supercapacitor in energy harvesting powered autonomous wireless sensor nodes

Yue, Xicai; Kiely, Janice; Farooq, Abdul; Champneys, Alan

Abstract

© 2017 IEEE. The supercapacitor is a candidate energy storage component for energy harvesting powered autonomous wireless sensor node aiming to achieve battery replacement-free, 'fit and forget' sensor node in low-power IoT applications. The leakage current of the supercapacitor provided by the manufacturer is tested long after post-charge, raising a concern relating to the uncertainty of the dynamic leakage current in the IoT applications where the supercapacitor frequently charges and discharges. This paper investigates the charge redistribution process which causes an equivalent capacitance change of the supercapacitor in a full IoT measurement period, and then proposes an experiment design to measure the dynamic leakage current of a supercapacitor for an IoT application. The results showed that the charge redistribution process is completed long before the end of the sleep period due to the low ratio of the amount of discharge in an active period to the total amount of charge the supercapacitor holds. It also showed that the average dynamic leakage current in an entire measurement period corresponds to the value provided by the manufacturer, indicating that leakage current is not an issue when supercapacitors is used for low-power IoT applications.

• Presentation Conference Type: Conference Paper (published)
• Conference Name: 2017 IEEE International Telecommunications Energy Conference (INTELEC)
• Start Date: Oct 22, 2017
• End Date: Oct 26, 2017
• Acceptance Date: Aug 4, 2017
• Online Publication Date: Dec 18, 2017
• Publication Date: Dec 18, 2017
• Deposit Date: Sep 26, 2017
• Publicly Available Date: Jan 10, 2018
• Journal: INTELEC, International Telecommunications Energy Conference (Proceedings)
• Print ISSN: 0275-0473
• Peer Reviewed: Peer Reviewed
• Volume: 2017-October
• Pages: 278-281
• ISBN: 9781538610190
• DOI: https://doi.org/10.1109/INTLEC.2017.8214147
• Keywords: supercapacitor, leakage current, charge redistribution, IoT
• Public URL: https://uwe-repository.worktribe.com/output/904138
• Publisher URL: http://dx.doi.org/10.1109/INTLEC.2017.8214147
• Additional Information: Title of Conference or Conference Proceedings : 2017 IEEE International Telecommunications Energy Conference (INTELEC)
• Contract Date: Sep 26, 2017