Active Cell Equalization Topologies Analysis for Battery Packs: A Systematic Review

With the increasing use of rechargeable lithium-ion battery packs in numerous applications, it calls for an effective evaluation of active battery cell equalization to enhance the whole battery pack's capacity and performance. Plenty of work has focused on cell equalizing circuit and control algorithm design. Still, none of them is devoted to a comprehensive analysis and comparison of cell balancing methods from the topology level. In this article, a review of the state-of-the-art active battery cell equalization methods is conducted, where it is classified as adjacent-based, nonadjacent-based, direct cell-cell, and mixed topologies. This classification can provide a comprehensive way to analyze and compare the existing active cell balancing methods' performance. Subsequently, the mathematical models of these balancing structures are developed, and extensive simulation results are provided to compare the performance of these equalization topologies in terms of equalization speed. It then comes up with an inclusive economic comparison between them, followed by a discussion.