SOC Estimation of Lithium-ion Batteries Based on Adaptive UKF

Abstract

Accurate estimation of the state of charge (SOC) of Lithium-ion batteries is the critical technology for developing Lithium-ion batteries. Aiming at the problem that the noise covariance of the UKF is fixed, an adaptive UKF algorithm is proposed in this paper. The adaptive UKF algorithm can estimate and correct the noise characteristics of the system in real-time, and suppress the possible filter divergence and improve the estimation accuracy of the SOC. By analyzing the simulation results of constant discharge and pulsed variable current pulse discharge, it is proved that the filtering effect of adaptive UKF is better and the accuracy is higher.