磷酸铁锂电池的改进建模及SOC估计

Modified modeling and SOC estimation of LiFePO_4 Li-ion battery

由于磷酸铁锂电池在多方面的优越性能,它在电动汽车领域的应用已经越来越广泛。文章针对磷酸铁锂电池,给出了其改进的PNGV模型,并通过电池恒流充放电特性和脉冲充放电特性实验,利用插值和最小二乘拟合方法进行电池模型参数辨识,实现了磷酸铁锂电池的较准确建模,并采用扩展卡尔曼滤波算法(EKF)完成了电池荷电状态(SOC)的准确估计。

Because of the excellent characteristics of the LiFeP04 Li-ion battery, it has been applied widely in electric vehicle. An improved PNGV battery model which is designed especially for this ne- west type of Li-ion battery is built in this paper. The input current and output terminal voltage data are collected by the constant current and pulse current charging-and-discharging characteristic experi- ments, the parameter identification is implemented by the interpolation and the least square fitting, and the accurate mathematic model of the I.iFePO~ I.i-ion battery is obtained. Finally the extended Kalman filtering（EKF） algorithm is used to estimate the state of charge（SOC） of battery.