Highly Integrated Centralized Equalizer Based on Zeta-Sepic Converter for Series-Connected Battery Strings

In this manuscript, a centralized battery equalizer with high integration is presented and analyzed. The proposed equalizer applies the power switch integration technology to the traditional centralized equalization system, and integrates the bidirectional switch used for battery selection in the switch array and the power switch used for energy conversion in the bidirectional zeta-sepic converter, thereby the power density of the equalization system can be effectively enhanced. Besides, the presented balancing scheme obtains the characteristics of controllable equalization current, small number of components, and high conversion efficiency, which has broad application prospect and practical value. The theoretical derivations and design considerations are comprehensively addressed. Finally, an experimental platform is constructed, and the comparison and test results fully validate the availability and feasibility of the presented zeta-sepic converter based centralized equalizer.