Energy Storage Science and Technology ›› 2025, Vol. 14 ›› Issue (5): 2081-2097.doi: 10.19799/j.cnki.2095-4239.2025.0046

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

SOH estimation of real-world power batteries based on Soft-DTW algorithm and multisource reature fusion

Ping DING1(), Taotao LI1, Linfeng ZHENG2, Weixiong WU1()   

  1. 1.Energy and Electricity Research Center, Jinan University, Zhuhai 519070, Guangdong, China
    2.Sino-German College of Intelligent Manufacturing, Shenzhen Technology University, Shenzhen 518118, Guangdong, China
  • Received:2025-01-10 Revised:2025-03-06 Online:2025-05-28 Published:2025-05-21
  • Contact: Weixiong WU E-mail:yeeurl@163.com;weixiongwu@jnu.edu.cn

Abstract:

The State of Health (SOH) of electric vehicle (EV) power batteries is a critical factor in ensuring efficient operation and extending service life. However, accurately assessing SOH is challenging owing to the complex and variable charging patterns in real-world EV usage, large sampling intervals in individual charge-discharge cycles, and missing feature data. To address these challenges, this study proposes a multisource feature fusion method for SOH estimation method using real-world vehicle operation data. The proposed method utilizes the soft dynamic time warping (Soft-DTW) algorithm to dynamically fuse parameters from weekly charging segment incremental capacity (IC) curves, generating an overall weekly IC fusion feature. By integrating these fused IC curve features with statistical features, a multisource feature set is constructed. Furthermore, a real-world SOH estimation model based on the Bidirectional Gated Recurrent Unit-eXtreme Gradient Boosting (BiGRU-XGBoost) is proposed. The model was tested using a real-world dataset comprising 20 EVs. K-fold cross-validation results demonstrates that the proposed SOH estimation method achieves a root mean square error (RMSE) within 1.21% and a mean absolute error (MAE) below 0.9%. Comparative experiments with GRU-XGBoost and long short-term memory (LSTM) models further validate the superiority of the BiGRU-XGBoost model, showing 36.1% and 47.6% reductions in RMSE. These findings highlight the enhanced robustness and generalization capabilities of the BiGRU-XGBoost model.

Key words: electric vehicle, state of health estimation, incremental capacity

CLC Number: