Joint optimization of efficiency and volume for an inductor‐based battery balancing circuit

Abstract

SummaryIn recent years, with the increase in the number of electric vehicles, the number of retired power batteries, which predominantly include lithium‐ion batteries, has surged. Recycling these retired power batteries can reduce environmental pollution and resource waste. However, the voltage of a single lithium‐ion battery is low, and multiple single batteries need to be connected in series to satisfy application requirements. This use of multiple batteries results in inconsistencies in battery cell parameters. As the number of series connections increases, this inconsistency problem becomes more prominent, and it can even decrease the system's capable number of charge and discharge cycles. Due to the wide voltage performances of lithium‐ion batteries, inductive balancing circuits are more suitable for balancing a series of lithium‐ion battery cells. This paper considers a single inductor balancing circuit and proposes a joint optimization of efficiency and volume. By flexibly allocating the weight coefficients of efficiency and volume, the algorithm can optimize the overall efficiency and volume of the hardware circuit according to different circuit design requirements. Finally, the effectiveness of the proposed joint optimization method is verified by building a laboratory prototype.