Series‐connected battery equalization system: A systematic review on variables, topologies, and modular methods

Abstract

Series-connected lithium battery packs are widely adopted in industries such as electrical vehicles and large-scale energy storage systems. It is necessary to configure an equalization system for them to reduce the inconsistency of single cells, to ensure the battery pack cycle capacity. Although many novel active converters have been proposed for equalization, there still lacks systematic analyses on variables, topologies, and modular methods. Therefore, this paper provides a systematic review on the above aspects. Initially, an overall summary is present on current variables for equalization control. Second, the dominant structures are divided into cell-to-cell, cell-to-pack, and pack-to-pack topologies, and their characteristics are pointed out for comparison. And then, the modular methods, including single-layer-based, multi-layer-based, and hybrid integrations are evaluated via graph theory. Some key issues and potential research directions are given, which are expected to offer assistance on the selection of appropriate variables and topologies for equalization systems in the future.

The control and evaluation method of the cascaded buck–boost converter for equalization on battery strings

“…To enhance the overall performance of the lithium battery pack and extend the cruising range of new energy vehicles, a variety of equalization circuits have been proposed and implemented. 3 A balancing current ratio (BCR)-based algorithm with batch-based run-to-run control is proposed in Tang et al, 4 which obtains a high capacity of utilization and theoretical capacity. The proposed three-charge stage balancing charge strategy shows better performance than the traditional constant current to constant voltage (CC-CV) charging strategy, 5 whereas the additional two power sources for balancing charging will inevitably increase the cost of the whole system.…”

“…To enhance the overall performance of the lithium battery pack and extend the cruising range of new energy vehicles, a variety of equalization circuits have been proposed and implemented 3 . A balancing current ratio (BCR)‐based algorithm with batch‐based run‐to‐run control is proposed in Tang et al, 4 which obtains a high capacity of utilization and theoretical capacity.…”

Design and Implement of Staggered Parallel Lithium Battery Equalization Converter With Jumper Switches

“…Normally, an independent battery needs to be connected in series or paralleled into groups to output the required power in industrial applications due to its electrochemical limitations. However, individual batteries are subject to certain inconsistencies due to the manufacturing process and operating environment factors (Dai et al, 2021). This inconsistency gradually accumulates, thereby increasing the gap in individual recyclable capacity and reducing the overall performance of the battery packs.…”

Vehicle auxiliary safety driving monitoring system

“…Recent years have seen rapid developments in intelligent transportation technologies, such as intelligent vehicles and intelligent transportation systems (ITS). All of these systems can be designed to improve the safety and management of transportation systems [1][2]. There are active safety systems that are widely used.…”