Topology, Analysis, and Modeling of Voltage Equalizers Based on Reutilization Technique for Supercapacitor Storage System

The voltage equalizers based on the switched capacitor are widely used in energy storage system because of its simple circuit structure and easy realization. However, the voltage stress and the number of bypass capacitors in traditional switched-capacitor equalizers are enormous due to the large number of energy storage cells, and they can only realize balance of a single string. Therefore, three improved switched-capacitor equalizers based on reutilization technique are proposed to solve the problems. The supercapacitors in the circuit can be used as energy storage cells and energy transfer cells through the reutilization of energy, thus avoiding the extensive use of bypass capacitors and achieving the balance between strings. Meanwhile, the design difficulty of equivalent equalization resistance and the switch number are greatly reduced. The circuit configuration, operation principle, and modeling are illustrated in detail. Finally, three experiment prototypes are established. The results verify the feasibility of the proposed topologies.