State of Charge Estimation of Lithium-Ion Battery Using Extended Kalman Filter Based on a Comprehensive Model

The state of charge (SOC) is an important index for power battery system. To obtain its accurate value,a comprehensive equivalent circuit model that parameters change depend on SOC was estiblished in this paper by using the lithium-ion battery hybrid pulse power characteristic data. Then the Extended Kalman filter (EKF) method is applied to estimate the SOC under the working condition. Numerical simulations are conducted to verify the effectiveness of the model and the EKF method. The results show that the EKF method based on the dynamic model can satisfy the accuray requirements.