磷酸铁锂电池二阶可变阻容的模型研究

Research on the Model of the Second-Order Variable Resistance-Capacitance of Lithium Iron Phosphate Battery

精确的电池模型是动力电池荷电状态(State of Charge,SOC)估计的基础,提高模型精度可从电池内部特性出发。提出二阶阻容可变参数等效电路模型,能够反映电池内部双极化效应,同时用可变的参数描述电池内部动态变化过程。通过对锂离子电池充放电实验和HPPC测试,结合MATLAB拟合工具,辨识出不同SOC下各参数的值,基于SIMULINK搭建仿真模型。对比仿真结果,所建立模型的端电压平均误差为12.36mV,相比于固定参数传统模型的31.50mV,精度提高了60.76%,更能准确描述锂离子电池内部的静动态特性。

Accurate battery model is the basis of state of charge(SOC)estimation of power battery.Improving model accuracy can be based on the internal characteristics of the battery.A second-order RC variable parameter equivalent circuit model is pro⁃posed.Which can reflect the internal dual-polarization effect of the battery and use variable parameters to describe the internal dy⁃namic change process of the battery.Through the charging and discharging experiments of lithium-ion batteries and HPPC test⁃ing.Combined with MATLAB fitting tools,the parameter values under different SOC were identified,and the simulation model was built based on SIMULINK.Comparing the simulation results,the average terminal voltage error of the established model is 12.36mV.Compared with the 31.50mV of the traditional model with fixed parameters.The accuracy is improved by 60.76%,Which can more accurately describe the static and dynamic characteristics of the lithium-ion battery.