锂离子动力电池电路模型的频率特性分析

Frequency characteristics analysis of lithium-ion power battery circuit model

针对动力系统的不同和行驶工况的差异,锂离子动力电池电路模型具有不同的适用性。以铁路客车锂离子动力电池模型研究为背景,选取电路模型分析其本身具有的频率特性,推导出截止频率的计算公式。以功率型锰酸锂串联电池组为例,完成等效电路模型的参数辨识,由辨识得到的结果计算出一阶Thevenin模型和PNGV模型的截止频率。对比两类模型在全SOC区间的频带宽度和周期特性,定量分析各自不同的适用范围,指出一阶Thevenin模型的低通滤波特性和PNGV模型的带通滤波特性。通过分析表明,针对频率特性一阶Thevenin模型较PNGV模型更适合于铁路客车电池模型仿真,为进一步研究铁路客车电池建模提供依据。

According to the difference of power system and running condition, the applicability of the lithium-ion power battery circuit model is different. Taking the research of lithium-ion power battery model for passenger train as the background, the circuit model was selected, the frequency characteristics were analyzed, and the calculating formula of cut-off frequency was deduced. As traction Li Mn2O4 series battery pack being research object, the equivalent circuit model parameter identification was accomplished, and the cut-off frequency of the first order Thevenin model and PNGV model was calculated through the results by parameter identification. The band width and cyclophysis about two kind of model in the whole range of SOC was compared, the different scope of application in quantitative was analyzed, and it was pointed out that low-pass filtering properties of the first order Thevenin model and band-pass filtering properties of the PNGV model. The analysis shows that first order Thevenin model is more suitable for passenger train battery model simulation in frequency characteristic. The basis for further research of battery modeling was provided.