Abstract: Compared with traditional batteries, lithium-ion batteries have the advantages of high energy density, no memory effect, superior cycle performance, and no toxic and harmful substances. Effectively managing the working state of the battery and accurately estimating the state of charge (SOC) of the battery are of great significance for the safe operation of the battery and prolonging its service life. In this paper, 18650 ternary lithium battery is taken as the research object. Firstly, the influencing factors of lithium-ion battery parameters are analyzed, and then the equivalent circuit model of the battery is discussed. Considering that the traditional Kalman filter algorithm is more applied to linear systems, for the nonlinear situation of the internal system of the power battery, needs to extend the algorithm, that is, the system equation needs to be linearized. Finally, in order to verify and test the effect of our estimation system, the estimation scheme is programmed in MATLAB/Simulink, and the battery SOC estimation system is simulated and compared. It is verified that the algorithm errors under constant current discharge and hybrid pulsepower characteristic conditions are not more than 8%.

Key words: Power battery; State of charge; Equivalent circuit model; Simulation verification

摘要： 锂离子电池相较于传统电池，具有能量密度大、没有记忆效应、循环性能优越、不含 有毒有害物质等优点。有效管理电池的工作状态，准确估计电池荷电状态（SOC），对电池的 安全工作以及延长其使用寿命具有重要意义。文章以 18650 三元锂电池作为研究对象，首先 对锂离子电池的参数影响因素进行分析，然后对电池的等效电路模型进行讨论。考虑到传统 卡尔曼滤波算法更多应用于线性系统，针对动力电池内部系统的非线性情况，需要对算法进 行扩展，即需要将系统方程进行线性化处理。最后为了验证与测试估算系统的效果，在 MATLAB/Simulink 中完成估算方案的编程，并对电池 SOC 估算系统进行仿真对比实验，经验 证，恒流放电和混合功率脉冲特性两种工况下的算法误差均不超过 8%。

关键词: 动力电池；荷电状态；等效电路模型；仿真验证