Battery packs for most applications are series strings of electrochemical cells. Due to manufacturing variations, temperature differences, and aging, the individual cells perform differently. When a complete pack is charged and discharged as a single two-terminal circuit element, some cells are chronically overcharged, undercharged, or overdischarged, all of which act to reduce cell life. The performance and life of the complete pack is limited by the weakest cell. Many methods have been proposed and explored to mitigate this problem. In the present work, a switched-capacitor converter is shown to be a simple and effective method to maintain equal cell or monoblock charge conditions. Design criteria are discussed.
J. W. Kimball et al., "Increased Performance of Battery Packs by Active Equalization," Proceedings of the IEEE Vehicle Power and Propulsion Conference, 2007. VPPC 2007, Institute of Electrical and Electronics Engineers (IEEE), Sep 2007.
The definitive version is available at http://dx.doi.org/10.1109/VPPC.2007.4544145
IEEE Vehicle Power and Propulsion Conference, 2007. VPPC 2007
Electrical and Computer Engineering
Keywords and Phrases
Battery Equalization; Battery Pack; Electric Vehicle
Article - Conference proceedings
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