High-precision state of charge estimation of urban-road-condition lithium-ion batteries based on optimized high-order term compensation-adaptive extended Kalman filtering.

Feng, Renjun; Wang, Shunli; Yu, Chunmei; Zhou, Heng; Fernandez, Carlos

Abstract

It is significant to improve the accuracy of estimating the state of charge (SOC) of lithium-ion batteries under different working conditions on urban roads. In this study, an improved second-order polarized equivalent circuit (SO-PEC) modeling method is proposed. Accuracy test using segmented parallel exponential fitting parameter identification method. Online parameter identification using recursive least squares with variable forgetting factors(VFFRLS). An optimized higher-order term compensation-adaptive extended Kalman filter (HTC-AEKF) is proposed in the process of estimating SOC. The algorithm incorporates a noise-adaptive algorithm that introduces noise covariance into the recursive process in real-time to reduce the impact of process noise and observation noise on the accuracy of SOC estimation. Multiple iterations are performed for some of the processes in the extended Kalman filter(EKF) to compensate for the accuracy impact of missing higher-order terms in the linearization process. Model validation results show over 98% accuracy. The results after comparing with the EKF algorithm show a 4.1% improvement in SOC estimation accuracy under Hybrid Pulse Power Characterization(HPPC) working conditions. 2.7% improvement in accuracy in Dynamic Stress Test(DST) working conditions. 2.1% improvement in Beijing Bus Dynamic Stress Test(BBDST) working conditions. The superiority of the algorithm is demonstrated.

Citation

FENG, R., WANG, S., YU, C., ZHOU, H. and FERNANDEZ, C. 2023. High-precision state of charge estimation of urban-road-condition lithium-ion batteries based on optimized high-order term compensation-adaptive extended Kalman filtering. Journal of The Electrochemical Society [online], 170(5), article 050539. Available from: https://doi.org/10.1149/1945-7111/acd303

• Journal Article Type: Article
• Acceptance Date: May 23, 2023
• Online Publication Date: May 31, 2023
• Publication Date: May 31, 2023
• Deposit Date: May 23, 2023
• Publicly Available Date: Jun 1, 2024
• Journal: Journal of the Electrochemical Society
• Print ISSN: 0013-4651
• Electronic ISSN: 1945-7111
• Publisher: Electrochemical Society
• Peer Reviewed: Peer Reviewed
• Volume: 170
• Issue: 5
• Article Number: 050539
• DOI: https://doi.org/10.1149/1945-7111/acd303
• Keywords: State of charge (SOC); Second-order polarized equivalent circuit (SO-PEC); Estimation; Lithium-ion batteries
• Public URL: https://rgu-repository.worktribe.com/output/1972470