304 / 2021-11-09 17:10:50

Research on SOC Estimation of Lithium Battery for Electric Vehicle Based on EKF Algorithm

Electric vehicle, SOC estimation, lithium battery, EKF algorithm

New energy electric vehicles have significant ad­vantages such as alleviating the shortage of fossil energy and avoiding environmental pollution, and have been vigorously promoted all over the world. Currently, electric vehicles are mainly powered by lithium batteries. Accurate SOC estimation can ensure the safe and efficient operation of electric vehicles, thereby increasing the service life of electric vehicles. In this paper, the second-order RC equivalent circuit model of lithium battery is established and the parameters of the model are identified. Secondly, the principle of EKF algorithm is introduced and applied to lithium battery SOC estimation. Finally, the simulation results indicate that the maximum estimation error of the SOC algorithm in this paper can be controlled within 3.4% under various working conditions, which proves the effectiveness of the SOC estimation algorithm.