基于双非线性预测滤波法的锂离子电池SOH估计

State of health estimation of lithium ion battery by dual nonlinear predictive filter for electric vehicles

动力电池的健康状态(SOH)估计是电动汽车电池管理系统的关键技术之一。提出了一种基于双非线性预测滤波法的锂离子电池SOH估计方法。基于Thevenin等效电路模型来表达电池的性能,基于双非线性预测滤波法对电池的容量和内阻进行估计从而实现SOH的在线估计,基于磷酸铁锂电池的循环寿命测试对提出的方法进行验证,结果表明,基于双非线性预测滤波法的SOH估计方法能够在电池的整个生命周期内实现SOH的精确预测。

State of health(SOH)estimation is one of the key technologies for battery management system in electric vehicles.In this paper,the dual nonlinear predictive filter(DNPF)based SOH estimation method is proposed.First,the Thevenin equivalent circuit battery model is built up to characterize the battery dynamic behavior.Then,the SOH estimation method is established by online estimating the battery capacity and resistance using DNPF.Finally,the proposed method is validated based on the cycle life test of a LiFeO4 battery cell,the validation results show that the DNPF based SOH estimation method is able to accurately estimate the battery SOH during the battery cycle life.