磷酸铁锂电池SOC估算方法研究

磷酸铁锂电池宽的电压平台和严重的两端极化不利于SOC的估算,但电池的SOC对电池组不一致性和寿命有着重要的影响,因此本文在磷酸铁锂电池的现有SOC估算分析基础上,研究了反应电池电化学特征的伏安特性曲线,提出了不同充电倍率、不同老化程度下可靠和准确的△Q/△V分析方法,利用电池在充电过程中的峰值△Q修正电池SOC值。为电动汽车电池组在线均衡和智能电池系统的管理策略提供依据。

Research on SOC estimation for LiFePO4 Li-ion batteries

The very broad plateau of LiFePO4 Li-ion batteries and serious polarization on both ends are not conducive to SOC estimation,but SOC value has definite major influence upon cell inconsistency and service life.Based on the existing SOC estimation methods of LiFePO4 Li-ion batteries and the analysis of voltammeter curve correspond-ing to electrochemical characteristics,a reliable and accurate method of △Q/△V under different charging rates and aging stages is presented in detail,and the SOC value is revised by peak △Q during the charging process.The online equaliza-tion of battery packs and control strategies of intelligent battery management system for electric vehicle are validated by the accuracy of SOC estimation.