Energy Storage Science and Technology

   

Lithium-ion batteries SOH estimation based on gaussian processed regression optimized by egret swarm optimization

Chunling WU1,2(), Liding WANG1,2, Yong Lu1,2, Yao MA1,2, Hao Chen1,2, Jinhao Meng3   

  1. 1.School of Energy and Electrical Engineering, Chang' an University, Xi'an 710064, Shaanxi Province, China
    2.Shaanxi Key Laboratory of Transportation New Energy Development, Application and Vehicle Energy Saving Technology, Xi'an 710064, Shaanxi Province, China
    3.School of Electrical Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi Province, China
  • Received:2025-01-06 Revised:2025-02-17 Online:2025-02-25

Abstract:

The estimation of the State of Health (SOH) of lithium-ion batteries directly impacts the safety and reliability of battery systems and is a crucial function of battery management systems. Addressing the issues in existing data-driven SOH estimation methods, such as the lack of uncertainty representation and incomplete decoupling of training and testing data, this paper proposes an SOH estimation method based on the Egret Swarm Optimization Algorithm (ESOA) and Gaussian Process Regression (GPR). First, health features related to battery aging are extracted from the charging voltage, current, and relaxation voltage data of similar batteries, and features with high correlation to battery capacity are selected through Pearson correlation analysis. Subsequently, a Gaussian Process Regression model with a squared exponential kernel function is employed for SOH estimation, with the hyperparameters of the GPR model optimized using the Egret Swarm Optimization Algorithm. Finally, the proposed model is validated using NCA and NCM battery datasets from Tongji University to assess its accuracy and robustness. Experimental results demonstrate that the proposed method effectively improves the precision and reliability of SOH estimation. For the tested battery types, the maximum RMSE and MAE of SOH estimation errors are 0.0028 and 0.22%, respectively, representing improvements of 58.82% and 57.69% compared to conventional GPR models. Furthermore, the method enables SOH interval estimation, thereby avoiding safety risks caused by overestimating battery SOH.

Key words: Lithium-ion battery, State of health, Egret swarm optimization algorithm, Gaussian process regression, Interval Estimation

CLC Number: