基于MATLAB和EKF的锂离子电池SOC估算算法研究

Research on SOC Estimation Algorithm of Li-ion Battery Based on MATLAB and EKF

本文研究锂离子电池参数估计和荷电状态的估算方法。基于电池模型的优缺点及对电池动静态特性的反应,使用MATLAB/Simulink建立电池的二阶等效电路模型,并使用Parameter工具箱对电池参数进行辨识,建立动态准确的电池模型。接着,针对所建立的电池模型方程,选择扩展卡尔曼滤波对电池荷电状态进行估算。经过优化后,实验结果表明,本文提出的估算方法最大绝对误差为1.8%,均方根误差为0.74%。该方法能够在2%误差之内准确地估算电池的荷电状态,具有很好的实用性,可以有效地用于电池系统的设计和运行控制。

The purpose of this article is to investigate the estimation of the parameters and the state of charge of lithium-ion batteries.Firstly,a second-order equivalent circuit model is constructed with MATLAB/Simulink,taking into account the strengths and weaknesses of different battery models and their response to both dynamic and static batery characteristics.By utilizing the Parameter Tool Box,the battery parameters can be accurately and dynamically modeled.The battery model is then utilized for an Extended Kalman Filter to estimate the state of charge of the battery.After optimization,the experimental results indicate that the proposed estimation method exhibites a maximum absolute error of only 1.8%and root mean square error of 0.74%.This method can reliably estimate the state of charge of the battery within an error range of 2%,which makes it practical for the design and operation control of the battery system.