基于变阶RC网络的锂离子电池等效电路模型

Equivalent circuit model of lithium ion battery based on variable order RC network

针对电动汽车锂离子电池阻容(resistance-capacitance,RC)模型存在低阶模型近似程度低和高阶模型结构复杂的问题,提出一种兼具实用性和精确性的可变阶RC网络等效电路模型。在充分理解磷酸铁锂电池特性的基础上,对电池进行了测试实验,利用赤池信息量准则(Akaike information criterion,AIC)对等效电路模型阶数进行辨识,并用CF工具箱对模型参数进行识别,在MATLAB/Simulink中搭建变阶RC等效电路模型,对恒流放电和脉冲放电2种工况进行仿真验证。结果表明,变阶RC模型的平均估算误差在0.5%以内,体现了该模型的优越性。

Aiming at the problems of the bad approximation of low-order model and the complicated structure of high-order model in resistance-capacitance(RC)model of electric vehicle lithium-ion battery,a variable-order RC network equivalent circuit model with both practicality and accuracy was proposed.On the basis of fully understanding the characteristics of LiFePO4 battery,the battery was tested by Akaike information criterion(AIC)to identify the order of the equivalent circuit model,and CF toolbox was used to identify the model parameters.A variable order RC equivalent circuit model was built in MATLAB/Simulink to simulate constant current discharge and pulse discharge.The results show that the average estimation error of the variable order RC model is within 0.5%,which reflects the superiority of the model.