Systems Engineering and Electronics ›› 2025, Vol. 47 ›› Issue (10): 3270-3277.doi: 10.12305/j.issn.1001-506X.2025.10.14

• Systems Engineering • Previous Articles    

SOC estimation method for lithium-ion batteries based on degradation injected field-circuit coupling model

Bo SUN1,2, Tongshu LIN1, Zeyu WU1,2,*, Cheng QIAN1,2, Junlin PAN1, Leyang ZHOU1, Keming DONG3   

  1. 1. School of Reliability and Systems Engineering,Beihang University,Beijing 100191,China
    2. National Key Laboratory of Reliability and Environmental Engineering Technology,Beijing 100191,China
    3. Aerospace Science and Industry Defense Technology Research Testing Center,Beijing 100854,China
  • Received:2024-09-23 Online:2025-10-25 Published:2025-10-23
  • Contact: Zeyu WU

Abstract:

At present, the estimation methods for state of charge (SOC) takes little account of the combined effects of temperature and degradation, as well as their coupling relationship, which leads to incomplete model representation and insufficient SOC estimation accuracy after battery performance degradation. In regard to this, a lithium-ion battery SOC estimation method based on degradation injection field-circuit coupling model is proposed to achieve accurate estimation of SOC throughout the entire lifecycle. Firstly, a field-circuit coupled model by coupling the equivalent circuit model with the multi physics field model is established to describe the effect of temperature. Then, the offline parameter identification method is used to inject factors such as temperature and degradation into the parameters of the equivalent circuit model. Finally, a surrogate model is built to improve computational efficiency and achieve online SOC estimation. The verification results of the case indicate that compared to other methods, the proposed model has a smoother prediction curve and higher accuracy in estimating the degradation of lithium-ion batteries after long-term operation.

Key words: lithium-ion battery, state of charge (SOC) estimation, field-circuit coupling model, degradation injection, surrogate model

CLC Number: 

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