基于双向DC-DC变换器的串联电池组主动均衡电路

Active Equalization Circuit of Series Battery Pack Based on Bidirectional DC-DC Converter

针对单体电池串联成组使用时出现不一致性的问题,提出了一种基于双向DC-DC变换器的串联电池组主动均衡电路。使用双向DC-DC变换器将单体电池中的高能量输送到能量低的单体电池中,无需额外的存储组件来存储和传送能量,减少了能量损失,提高了均衡效率。根据电池开路电压(open circuit voltage,OCV)与荷电状态(state of charge,SOC)之间近似分段线性的关系,采用以电压和SOC双变量作为均衡策略,通过相互实时修正电压均衡和SOC均衡,使得电池组间能量动态趋于一致。最后通过搭建由4节单体电池组成的均衡电路实验平台,对提出的均衡电路和均衡控制策略进行有效性验证。

Aiming at the inconsistency of single battery in series,an active equalization circuit of series battery pack based on bidirectional DC-DC converter is proposed.The DC-DC converter reduces the energy loss in the single battery and improves the storage efficiency without using the DCDC converter.According to the approximate piecewise linear relationship between battery open circuit voltage(OCV)and state of charge(SOC),using voltage and SOC bivariate is used as the equalization strategy to correct the voltage equalization and real time SOC equilibrium to make the energy dynamics between battery packs tend to be consistent.Finally,the effectiveness of the proposed equalization circuit and equalization control strategy is verified by building an equalization circuit experimental platform composed of four single batteries.