基于最大洛伦兹半径的锂离子电池模组健康状态评估  

State of Health Estimation of Lithium-ion Battery Module Based on the Maximum Lorenz Radius

作　　者：刘伟 胡厚鹏 肖艳红 LIU Wei;HU Houpeng;XIAO Yanhong(Electric Power Research Institute of Guizhou Power Grid Co.,Ltd.,Guiyang,Guizhou 550002,China)

机构地区：[1]贵州电网有限责任公司电力科学研究院,贵州贵阳550002

出　　处：《广东电力》2025年第1期1-8,共8页Guangdong Electric Power

基　　金：贵州省科技支撑计划项目(黔科合支撑[2022]一般015);中国南方电网有限责任公司创新项目(GZKJXM20220036)。

摘　　要：健康状态(stage of health,SOH)评估是电池系统的关键技术之一,其精度关系到电池系统能否安全运行。为此提出一种基于洛伦兹图(Lorenz plot,LP)的锂离子电池模组SOH快速评估方法,通过提取一定荷电状态(state of charge,SOC)区间的模组内不同电芯电压的最大洛伦兹半径(maximum Lorenz radius,MLR)作为该模组SOH的健康因子。研究结果表明,随着电池模组的老化,在放电曲线的低SOC范围内,模组的MLR值逐渐增大。当SOC区间为20%~30%时,MLR-SOH关系式呈线性负相关,拟合优度大于0.98。无论采用1/3 C倍率还是1 C倍率放电电压数据计算模组的MLR值,在10%~20%、20%~30%、30%~40%SOC区间,MLR-SOH关系式的拟合优度均大于0.97。采用从10%开始的任一SOC区间的放电电压数据计算模组的MLR值时,MLR-SOH关系式的拟合优度均在0.97以上,表明基于MLR的电池模组SOH评价方法在倍率和SOC窗口的选取上具有较强的鲁棒性,这将为该方法的实际应用提供较为充足的选择。State of health(SOH)assessment is one of the key technologies for battery systems,and its accuracy is related to whether the battery system can operate safely.A novel fast SOH evaluation method for lithium-ion battery modules is proposed based on Lorenz plot(LP).The maximum Lorenz radius(MLR)of different cell voltages within a module at a certain state of charge(SOC)range is extracted as the health factor for the modules SOH.The research results show that the MLR value of the module gradually increases in the low SOC range of the discharge curves as the battery module ages.When the MLR values at 20%~30%SOC interval are extracted as health factors,the MLR-SOH relational expressions present a linear negative correlation with a goodness of fit of over 0.99.After the MLR value of the module was calculated using discharge voltage data at 1/3 C and 1 C rates,the goodness of fit of the MLR-SOH relational expressions was greater than 0.97 in the 10%~20%,20%~30%,30%~40%SOC range.When the MLR values of the module are calculated using voltage data from any SOC interval starting from 10%during discharge,the goodness of fit of the MLR-SOH relational expressions based on the discharge voltage data is above 0.97,indicating that the MLR-based battery module SOH evaluation method has strong robustness in the selection of magnification and SOC window.This will provide ample options for the practical application of this method.

关 键 词：磷酸铁锂 电池模组 洛伦兹图 健康状态 

分 类 号：TM912[电气工程—电力电子与电力传动]