Consensus-Based Cell Balancing of Reconfigurable Supercapacitors

Abstract

Reconfigurable circuits have emerged as a promising cell balancing solution in supercapacitor echelon applications. However, the classical decentralized control method of reconfigurable supercapacitors results in high-voltage profiles of cells, which degrades the lifetime of supercapacitors. In this article, we propose a consensus-based cell balancing approach for reconfigurable supercapacitors, where the cell voltages are synchronized and maintained as low as possible to alleviate the aging of supercapacitors. The switched systems theory and graph theory are utilized to characterize the cyber-physical model of reconfigurable supercapacitors. A consensus-based tracking control is designed to balance cell voltages. It is rigorously proved that the proposed cell balancing method can guarantee cell voltages converge to the reference voltage. A laboratory hardware testbed has been built to verify the effectiveness of the proposed method. Extensive experiment results show that the proposed method can prolong the lifetime of cells considerably when compared with existing methods. Some practical issues of the proposed method are also discussed.