SOC estimation of lithium battery pack based on segmented polymerization and Kalman filter
LIU Guangjun1, WU Siqi2
1. School of Electrical and Electronic Engineering, Hubei University of Technology, Wuhan，Hubei 430068, China; 2. Hubei Key Laboratory for High-efficiency Utilization of Solar Energy and Operation Control of Energy Storage System, Hubei University of Technology, Wuhan， Hubei 430068, China
摘要 针对原有的锂电池组荷电状态（state of charge，SOC）估算方式是在电池放电后进行测量，在电池内阻数值较大时难以获取明确的开路电压，导致其在锂电池组SOC估算上具有误差等问题,设计了基于分段聚合和卡尔曼滤波的锂电池组SOC估算方法.在构建等效电路模型的基础上，辨识锂电池参数，并定义开路电压等锂电池组SOC估算指标.分段聚合切换锂电池反馈路径，利用卡尔曼滤波线性递推估算锂电池组SOC数值.结果表明：以锂电池脉冲放电过程为测试条件，提出的方法估算结果与实际SOC值基本一致，在SOC为0.6时，该方法能将SOC估算相对误差控制在0~0.4%.
Abstract：By the original estimation method, the state of charge (SOC) of lithium battery pack is measured after battery discharge. When the battery internal resistance is large, it is difficult to obtain clear open circuit voltage, leading to errors in SOC estimation of lithium battery pack. To solve the problem, the SOC estimation method of lithium battery pack based on segmented polymerization and Kalman filter was designed. Based on the construction of equivalent circuit model, the parameters of lithium battery were identified, and the SOC estimation indexes such as open circuit voltage were defined. The feedback path of lithium battery was switched by piecewide polymerization, and the SOC value of lithium battery was estimated by linearly recursive Kalman filter. The experimental results show that under the pulse discharge condition of lithium battery, the estimation result of the proposed method is basically consistent with the actual SOC value, and the estimation error can be controlled within 0.4% when SOC is 0.6.
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2024, Vol. 45 
