Abstract
The inevitable battery ageing is a bottleneck that hinders the advancement of battery-based energy storage systems. Developing a feasible health assessment strategy for battery pack is important but challenging due to the joint requirements of the computational burden, modeling cost, estimation accuracy, and battery equalization. This article proposes a balancing current ratio (BCR) based solution to achieve reliable state-of-health (SoH) estimations of all series-connected cells within a pack while significantly reduce the overall reliance on cell-level battery models. Specifically, after employing BCR to describe the properties of the balancing process, the voltage-based active balancing is combined into the SoH estimator design for the first time, leading to a weighted fusion strategy to effectively estimate SoHs of all cells within a pack. Hardware-in-the-loop experiments show that even if a parameter-fixed open-circuit-voltage-resistance model is used for modeling, the typical estimation error of our proposed solution can still be bounded by only 1.5%, which is 70% lower than that of the benchmarking algorithms. Due to the model-free nature of the integrated voltage-based balancing, the robustness and flexibility of the proposed pack SoH estimation solution are also significantly improved.
Original language | English |
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Pages (from-to) | 8055-8065 |
Number of pages | 11 |
Journal | IEEE Transactions on Industrial Electronics |
Volume | 69 |
Issue number | 8 |
Early online date | 3 Sept 2021 |
DOIs | |
Publication status | Published - Aug 2022 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 1982-2012 IEEE.
Funding
This work was supported in part by the Guangdong Scientific and Technological Project under Grant 2017B010120002, in part by the Guangzhou Scientific and Technological Project under Grant 202002030323, in part by the Hong Kong Research Grants Council CERG project under Grant 16207717 and Grant 16208520, in part by the High Value Manufacturing Catapult project under Grant 160080 CORE, and in part by the Shenzhen Science and Technology Innovation Commission under the Grant Shenzhen-Hong Kong Innovation Circle Category D Project: SGDX 2019081623240948.
Keywords
- Balancing current ratio (BCR)
- electric vehicle
- lithium-ion battery pack
- state-of-health (SoH) estimation