锂离子电池组容量差异辨识方法研究

电池组中普遍存在的不一致性问题,是制约电池组可用容量的重要因素之一。电池组内电池单体参数的差异性是描述电池组性能的重要指标,其中容量差异直接与电池组可用容量和优化控制等息息相关。文中对充电电流变化时电压曲线可进行简单缩放进行合理假设。基于该假设,建立一种快速容量差异辨识的方法,并从多种角度分析验证该方法的合理性和适应性。采用容量增量分析法修正SOC和内阻造成的估算误差。将该方法应用于具有较高电压采样精度和宽SOC工作范围的电池组充电数据上,基础算法误差低于2.5%,经修正后辨识误差可小于1.5%。该方法可以用于描述电池组内单体容量的不一致性,为电池组的均衡和维护提供参考。

Research on Capacity Difference Identification Method of Lithium-ion Battery Pack

Inconsistency is one of the important factors restricting the available capacity of battery packs.The difference in the parameters of the battery pack is an important indicator for describing the performance of the battery pack,and the difference in capacity is causally related to the available capacity and optimized control of the battery pack.A reasonable assumption for simple scaling of the voltage curve when the charging current changes was proposed.Based on this assumption,a fast capacity difference identification method was established.The rationality and adaptability of the method was analyzed and verified in various situations.The incremental capacity analysis method was used to correct the estimation error caused by SOC and internal resistance.This method was applied to battery pack charging data with high voltage sampling accuracy and wide SOC operating range.The basic algorithm error is less than 2.5%,and the identification error can be less than 1.5%after correction.The method proposed in this paper can be used to describe the inconsistency of the battery capacity within the battery pack and provide a reference for the balance and maintenance of the battery pack.