Modularized charge equalizer using multiwinding transformers for Lithium-ion battery system

In the Lithium-ion battery system of electric vehicles, the battery imbalance will lead to the decline of the safety and life cycle of the battery pack. To solve this problem, a modularized battery equalizer scheme using multipled transformers which have two secondary windings is proposed in this paper. With these secondary windings, modularization and energy balancing are achieved. Multiple equalization modules can operate at the same time and the energy can be transformed from the higher module to the lower one efficiently by the proposed equalizer.