考虑迟滞效应的电池极化电压误差修正方法

Polarization Voltage Error Correction Considering Battery’s Hysteresis Effect

以某三元软包电池为实验对象,对极化效应和迟滞效应的原理进行分析,通过改进的间歇充放电实验得到真实的极化电压值,证明了迟滞效应是造成极化电压计算误差的主要原因。进而基于二阶RC等效电路考虑迟滞电压的影响,提出一种改进的迟滞模型,将迟滞电压作为一项状态量,构建四阶状态方程。以SOC为输入,端电压为输出,得到迟滞效应对极化电压的影响继而进行修正。同时使用Simulink搭建传统二阶RC模型和改进的迟滞模型,将仿真得到的极化电压并与实验值进行对比。结果表明,改进的迟滞模型所得的极化电压曲线更贴近实验值,在恒流工况和动态应力测试工况(dynamic stress test,DST)下能达到更高的仿真精度。

In this paper,an NCM(LiNixCoyMnzO2)pouch cell is taken as experimental object.Through analysis of polarization effect and hysteresis effect principles,combined with improved intermittent charge and discharge experiment,true polarization voltage value is obtained,proving that hysteresis effect is the main reason for polarization voltage calculation error.Therefore,an improved hysteresis model is proposed.Based on the influence of hysteresis voltage in the second-order RC equivalent circuit,hysteresis voltage is used as a state quantity to construct a fourth-order equation of state.Taking SOC as input and terminal voltage as output,the influence of the hysteresis effect on polarization voltage is corrected.At the same time,Simulink is used to build a traditional second-order RC model and an improved hysteresis model.The simulated polarization voltage is compared with experimental values,showing that the polarization voltage curve obtained with the improved hysteresis model is closer to the experimental value with higher simulation accuracy under constant current conditions and dynamic stress test(DST).