Improved sliding mode based EKF for the SOC estimation of lithium-ion batteries

This paper combines the discrete sliding mode observer with the weighted innovation extended Kalman filter to improve the accuracy of the SOC estimation. The main work of this paper can be divided into two parts: (1) The proposed algorithms utilize the previous information and the current innovation by choosing proper weights to estimate the SOC accurately. (2) The improved discrete sliding mode observer is introduced into the weighted innovation extended Kalman filter to solve the chattering problem. The experimental results show that the accuracy of the SOC estimation is improved effectively.