Decentralized Non-Neighbor Active Charge Balancing in Large Battery Packs

Recently, active charge balancing of the cells in battery packs has been gaining importance over state-of-the-art passive balancing solutions. The main advantage of active balancing lies in the ability to transfer charge between cells rather than dissipating it thermally. This enhances the overall efficiency and energy output of battery packs. In this paper, we develop a new class of strategies for decentralized operation of charge transfers between non-neighboring cells using appropriate balancing hardware architectures. While the benefits of the active balancing approach with a centralized controller have been discussed in literature extensively, the implementation of adequate strategies for scheduling charge transfers in decentralized battery management systems, which promise to be more robust and modular, have not been studied sufficiently so far. Furthermore, existing decentralized strategies only deal with charge transfers between neighboring cells. In order to compare our novel distributed non-neighbor balancing strategies to existing neighbor-only balancing strategies, we implement them in an open-source simulation framework for decentralized battery management systems. Our results show that we are able to improve the two most important metrics of balancing time and losses by up to 63 % and 51 %, respectively.