A Novel Modularized Battery Charging and Balancing System

This paper proposes a novel distributed battery charging system and modularized balancing circuit for each battery pack connected in series. The distributed charging system is composed of modularized dc/dc converters and their corresponding battery packs. Phase shift control is adopted for the full bridge converter to achieve zero-voltage switching. The proposed balancing circuit can construct direct equalization path between cells or strings in Buck-Boost or flyback mode and the equivalent circuit model is established. Effects of unit voltages and a balancing strategy are discussed on this basis. Experimental results of a converter and an active balancing circuit module respectively revealed satisfactory performance, which verifies feasibility of implementation of the distributed charging system.