A strategy of estimating stage-of-charge of LiFePO4 battery based on Multirate Extended Kalman Filter

To accurately estimate the stage-of-charge of the lithium ion battery, a method based on Multirate Extended Kalman Filter is applied. A equivalent circuit model is built and the mode parameters are estimated based on the experiment data of charging and discharging the battery. The coulomb counting, Single Rate Extended Kalman Filter and Multirate Extended Kalman Filter are used to predict the SOC of the battery. Result in the Matlab indicates that the model can reflect the battery property and MREKF can accurately predict the SOC of lithium ion battery.