Energy Storage Science and Technology ›› 2024, Vol. 13 ›› Issue (3): 990-999.doi: 10.19799/j.cnki.2095-4239.2023.0735

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

SOH estimation of lithium-ion batteries using a convolutional Fastformer

Xiaoyu SHEN(), Congbo YIN()   

  1. College of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
  • Received:2023-10-19 Revised:2023-10-24 Online:2024-03-28 Published:2024-03-28
  • Contact: Congbo YIN E-mail:807101906@qq.com;250114287@qq.com

Abstract:

The state of health (SOH) of lithium-ion battery batteries is a crucial parameter for battery management systems, playing a substantial role in ensuring reliable operation and extending battery lifespan. This study aims to introduce an estimation method based on convolutional Fastformer model to improve the accuracy of data-driven SOH estimation for lithium-ion batteries. Initially, voltage and current curves from various charging stages of the lithium-ion battery are extracted for each cycle. These curves are then transformed into statistical health features, providing insights into the battery's aging characteristics. The Pearson correlation coefficient is used to analyze the relationship between selected statistical features and capacity, facilitating the identification of highly correlated health features and the elimination of redundant ones. Based on the strengths of convolutional neural networks and the linear complexity of Fastformer neural network, our approach combines the feature extraction capability of the former with local information mining of health features. The Fastformer's multihead attention mechanism efficiently summarizes contextual information within lengthy sequences. Model training time is reduced by optimizing hyperparameters using an orthogonal experimental method. Finally, a publicly available dataset is used for comparative evaluations, pitting our approach against other models such as CNN, GRU, and RNN. The results validate the accuracy of the convolutional Fastformer model, with maximum mean absolute error and root mean square error at only 0.25% and 0.29%, respectively, and a relative error within 0.08%. These findings demonstrate the high accuracy and stability achieved by the proposed method for SOH estimation.

Key words: lithium-ion battery, SOH estimation, orthogonal experiment, convolutional Fastformer

CLC Number: