Energy Storage Science and Technology ›› 2025, Vol. 14 ›› Issue (10): 3996-4008.doi: 10.19799/j.cnki.2095-4239.2025.0194

• Energy Storage Test: Methods and Evaluation • Previous Articles     Next Articles

IFFRLS-IMMUKF-based estimation of the state of charge of lithium iron phosphate batteries for commercial vehicles

Huawei WU1,2(), Chengze HE1,2, Qiang HONG1,2,4, Xiaogao ZHOU3, Mingjin LI4, Yajuan GU5   

  1. 1.Hubei Longzhong Laboratory, Hubei University of Arts and Science, Xiangyang 441053, Hubei, China
    2.Hubei Key Laboratory of Power System Design and Test for Electrical Vehicle, Hubei University of Arts and Science, Xiangyang 441053, Hubei, China
    3.Jiangxi Zhongyi Wisdom Technology Co. , Ltd, Yingtan 335000, Jiangxi, China
    4.Wuxi Mingheng Hybrid Technology Co. , Ltd, Wuxi 214177, Jiangsu, China
    5.Dongtai Secondary Vocational School in Jiangsu Province, Dongtai 224200, Jiangsu, China
  • Received:2025-03-03 Revised:2025-03-25 Online:2025-10-28 Published:2025-10-20
  • Contact: Huawei WU E-mail:whw_xy@163.com

Abstract:

State of charge (SOC) is a crucial parameter for characterizing the remaining capacities of electric vehicles (EVs). Accurate SOC estimation ensures EV safety and reliability. To facilitate accurate estimation of battery SOC in complex environments, the equivalent circuit model is constructed based on the characteristics of power batteries, and the equation of state (EOS) of the battery model is discretized. Further, to obtain the discretized EOS, the golden-jackal-optimization algorithm is combined with the forgetting factor recursive least square (FFRLS) algorithm to yield an improved FFRLS method for identifying the parameters of the battery model. Concurrently, the interacting multiple-model unscented Kalman filter (IMMUKF) algorithm is used to estimate the battery SOC, which is experimentally verified via dynamic stress tests (DST) and federal urban driving schedules (FUDS) at room and high temperatures. The experimental results indicate that the mean absolute error of the proposed improved IFFRLS-IMMUKF-based lithium-battery SOC-estimation method is within 0.8% and that the SOC-estimation accuracy for lithium iron phosphate batteries is high.

Key words: golden jackal optimization algorithm, forgetting factor recursive least square, interacting multiple model unscented Kalman filter, state of charge

CLC Number: