A Reconfigurable Supercapacitor Cell Balancing Circuit Based on a CLLC Converter and Multiple Switch Banks

This paper proposes a reconfigurable cell balancing circuit for supercapacitors by incorporating a CLLC converter and coupling each supercapacitor with a bank of six switches. When the supercapacitors are not exchanging energy with external sources or loads, static balancing can be achieved by properly configuring the switches to divide the supercapacitors into two groups based on their voltages. Each group is connected to one port of the CLLC converter and bidirectional power flows between the two groups can be implemented to balance the supercapacitors. If the supercapacitors are being charged or discharged, dynamic balancing can be implemented by bypassing certain supercapacitors with excessively high (during charging) or low (during discharging) voltages. Simulation results verify the static and dynamic balancing schemes.