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Robust State-of-Charge Estimation for Lithium-Ion Batteries Over Full SOC Range
- Source :
- IEEE Journal of Emerging and Selected Topics in Industrial Electronics. 2:305-313
- Publication Year :
- 2021
- Publisher :
- Institute of Electrical and Electronics Engineers (IEEE), 2021.
-
Abstract
- Safe and reliable management of rechargeable lithium-ion batteries relies on accurate state-of-charge (SOC) estimation. SOC estimation algorithms developed based on the conventional state-space model can be inaccurate when the slope of the battery SOC to open-circuit voltage ( $V_{\text{OC}}$ ) profile is close to zero, where the observability matrix of the conventional battery state-space model is ill-conditioned. This ill-conditioned observability issue is usually overlooked and results in unreliable SOC estimations. This article proposes a robust state-space model using a set of carefully selected states, making the proposed model well-conditioned over the full SOC range and insesitive to the slope of the SOC- $V_{\text{OC}}$ profile. The proposed model, therefore, solves the observability issue and improves the SOC estimation accuracy. To examine the performance of the proposed state-space model over the full SOC range, the battery is discharged using a standard electric vehicle driving profile. Experiments are further carried out in various environmental temperature conditions to validate the robustness of the proposed model. The results show that the proposed state-space model is robust against the change of the slope of the SOC- $V_{\text{OC}}$ profile and significantly improves the SOC estimation accuracy, rendering more than 30% improvement in various temperature conditions.
Details
- ISSN :
- 26879743 and 26879735
- Volume :
- 2
- Database :
- OpenAIRE
- Journal :
- IEEE Journal of Emerging and Selected Topics in Industrial Electronics
- Accession number :
- edsair.doi...........6e54273b55fc9e73a38391595c9415df