Research on layered active equalization method

DOI:	10.11809/bqzbgcxb2023.01.007
Keywords:	lithium iron phosphate battery; layered active equalization; state of charge; relative range; synchronous equalization
Abstract:	Aiming at the inconsistency of series battery pack in the existing applied energy storage system, and low equalization efficiency and long time of the single equalization method, this paper proposes a layered active equalization method based on inductance. In terms of topology, Buck Boost equalization circuit is used in the bottom layer to equalize the batteries in the battery unit; on the top layer, a single inductance equalization circuit is used to balance the inconsistency between battery units, and a relative range equalization control strategy based on the state of charge is adopted to realize the synchronization of the two layer equalization. The simulation results show that, compared with the two group layered equalization scheme, the equalization speed and the energy transfer efficiency of the proposed method increase by 19.3% and 0.8% respectively; compared with the step by step equalization control strategy, the equalization speed increases by 24.7% and the energy transfer efficiency increases by 1.2%, which effectively realizes the rapid equalization of series battery packs.
Published:	2023-01-28
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