纯电动汽车用磷酸铁锂电池的模型参数分析

Model Parameters Analysis of Lithium Iron Phosphate Battery for Electric Vehicle

鉴于纯电动汽车用磷酸铁锂电池在不同荷电状态下的电池特性差异较大,传统参数辨识方法得到的电池模型参数拟合精度较低。本文采用电化学阻抗谱来分析等效电路模型参数,以研究电池的电压特性和动态功率特性,通过综合分析实际充放电条件的主要特征来提取电池典型的参数辨识工况,并利用粒子群优化算法分析模型参数。在不同温度和使用区间的验证表明该方法的精度较高,为磷酸铁锂电池的进一步研究提供依据。

In view of that the fitting accuracy of battery model parameters obtained by traditional parameter identification method is relatively poor because the characteristics of lithium iron phosphate （ LiFePO4 ） battery for pure electric vehicle significantly differ at different states of charge, the parameters of equivalent circuit model are analyzed by using electrochemical impedance spectroscopy to study the voltage and dynamic power characteristics of battery in this paper. By comprehensively analyzing the main features of practical charge and discharge conditions, the typical parameter identification working modes of battery are extracted and the model parameters are analyzed with particle swarm optimization algorithm. The validation at different temperatures and usage intervals show that the accuracy of the scheme is rather high. This provides a basis for further investigation into lithium iron phosphate battery.