结合电路等效和UKF-EKF的锂电池SOC估算方法研究  

Study on SOC Estimation Method of Lithium Battery with Circuit Equivalent and UKF-EKF

作　　者：刘小菡 王顺利 苏杰 顾鹏程 马程 Liu Xiaohan;Wang Shunli;Su Jie;Gu Pengcheng;Ma Cheng(Southwest University of Science and Technology,(Mianyang,621010,China);School of Information Engineering SiChuan,(Mianyang,621010,china))

机构地区：[1]西南科技大学信息工程学院,四川绵阳621010 [2]检测研究所,四川绵阳621010

出　　处：《电源世界》2018年第8期15-18,共4页The World of Power Supply

基　　金：四川省大学生创新创业训练项目(201810619027);控制工程国防基础科研计划项目(B3120133002);四川省科技厅重点研发项目(2017FZ0013);四川省教育厅科研项目(17ZB0453);绵阳市科技局科技攻关项目(15G-03-3)

摘　　要：动力锂电池具备能量高、绿色环保等优点,逐步在汽车、航天、船舶等领域得以应用,常以成组形式被使用,以满足高电压、大容量的供电需求。但在生产与使用中单体不一致现象严重影响了电池的使用效率、寿命以及安全性,电池管理系统(Battery Management System, BMS)应运而生。动力电池荷电状态(State of Charge, SOC)的准确估算,对电动汽车电池管理系统(Battery Management System, BMS)有极其重要的意义。针对动力电池估算所存在的等效模型模拟电池充放电过程中真实低、常用算法精度损失等问题,基于二阶戴维南等效电路模型,对比分析扩展卡尔曼滤波(Extended Kalman Filter,EKF)算法与无迹卡尔曼滤波(Unscented Kalman Filter,UKF)算法优、缺点,提出UKF-EKF联合的SOC在线估算。以18490三元锂电池为检测对象,利用递推最小二乘法进行电池模型的参数辨识,将估计的SOC结果和试验测量结果进行比较,通过实验与仿真验证该方法的精度。实验结果表明,SOC估计精度在3%内,为锂电池等效电路模型的分析研究提供了一种可行方式。Power lithium batteries have the advantages of high energy, environmental protection and other advantages, and are gradually applied in the automotive, aerospace, marine and other fields. They are often used in groups to meet the high-voltage, large-capacity power supply needs. However, the inconsistency of monomer in production and use has seriously affected the efficiency, lifespan and safety of the battery. The battery management system(BMS) came into being. Accurate estimation of the state of charge(SOC) of the power battery is important for the Battery Management System(BMS) of the electric vehicle. Aimed at the problems of the low authenticity of the equivalent model, and the low accuracy of the common algorithm, this paper took the 18490 ternary lithium battery as the test object, studied second-order Thevenin equivalent circuit model. Based on the second-order Thevenin equivalent circuit model, Comparing the advantages and disadvantages of Extended Kalman Filter(EKF) algorithm and Unscented Kalman Filter(UKF) algorithm. a UKF-EKF combined SOC online estimation was proposed. The 18490 ternary lithium battery was used as the detection target. The parameters of the battery model were identified by using recursive least squares method. The estimated SOC results and experimental measurements were obtained. The results were compared and the accuracy of the method was verified by experiments and simulations. Experimental results show that the accuracy of SOC estimation is within 3%, which provides a feasible method for the analysis and study of the equivalent circuit model of lithium battery.

关 键 词：18490三元锂电池 二阶戴维南等效电路模型 UKF-EKF 递推最小二乘法 

分 类 号：TM912.9[电气工程—电力电子与电力传动]