Administrator by China Associction for Science and Technology
Sponsored by China Society of Automotive Engineers
Published by AUTO FAN Magazine Co. Ltd.

Automotive Engineering ›› 2022, Vol. 44 ›› Issue (4): 505-513.doi: 10.19562/j.chinasae.qcgc.2022.04.006

Special Issue: 新能源汽车技术-动力电池&燃料电池2022年

Previous Articles     Next Articles

State of Charge Estimation for Lithium-ion Battery Based on FFRLS-EKF Joint Algorithm

Jinlei Sun(),Xin Zou,Haotian Gu,Kai Cui,Jinda Zhu   

  1. State Grid Electric Power Research Institute,Nanjing  211106
  • Received:2021-10-21 Revised:2022-01-29 Online:2022-04-25 Published:2022-04-22
  • Contact: Jinlei Sun E-mail:jinlei.sun@njust.edu.cn

Abstract:

In view of the problem of a bit too large error of battery SOC estimation due to the existing SOC estimation method based on the battery model with constant parameters ignores the effects of working conditions and battery model parameters, a SOC joint-estimation method for lithium-ion batteries combining the forgetting factor least squares algorithm (FFRLS) and the extended Kalman filter (EKF) algorithm is proposed in this paper. The method utilizes the FFRLS algorithm to online identify the parameters of battery equivalent circuit model and correct the battery model in real-time first. Then, the EKF algorithm and real-time corrected battery model are used to estimate battery SOC. The experimental results show that the SOC estimation method proposed can effectively reduce the SOC estimation error caused by the variation of battery model parameters. In the experiments of pulse discharging test, pulse charging test and dynamic stress test, the final maximum errors of SOC estimation are 1.01%, 0.87% and 1.59%, respectively.

Key words: SOC estimation, parameter identification, RLS, EKF