State-of-charge estimation of LiFePO_4 battery using extended Kalman filter

To accurately estimate the state-of-charge(SOC) of the battery,based on the study of electrochemical impedance spectroscopy model,a simple equivalent circuit model was gained,which was appropriate to real application.And then based on some experiments,the parameter of the equivalent circuit model was estimated.The extended Kalman filter was used to predict the SOC of battery.In the end,Matlab was used to verify this method,and the result show that the EKF can accurately estimate the SOC of battery.