A Novel Method for Estimating State of Charge of Lithium Ion Battery Packs

Abstract:

In this paper a novel method for estimating state of charge (SOC) of lithium ion battery packs in battery electric vehicle (BEV), based on state of health (SOH) determination is presented. SOH provides information on aging of battery packs and it declines with repeated charging and discharging cycles of battery packs, so SOC estimation depends considerably on the value of SOH. Previously used SOC estimation methods are not satisfactory as they haven’t given enough attention to the decline of SOH. Therefore a novel SOC estimation method based on SOH determination is introduced in this paper; trying to compensate the deficiency for lack of attention to SOH. Real time road data are used to compare the performance of the conventionally often used Ah counting method which doesn’t give any consideration to SOH with the performance of the proposed SOC estimation method, and better results are obtained by the proposed method in comparison with the conventional method.

• Periodical: Advanced Materials Research (Volumes 152-153)
• Pages: 428-435
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.152-153.428
• Online since: October 2010
• Authors: Yuan Liao, Ju Hua Huang, Qun Zeng
• Keywords: Battery Electric Vehicle (BEV), Equivalent Coulombic Efficiency, Extended Kalman Flter (EKF), State of Charge (SOC), State of Health

References

[1] Piller S, Perrin M, Jossen A. Methods for state-of-charge determination and their applications. Power Sources 96 (2001) 113-20.

DOI: 10.1016/s0378-7753(01)00560-2

[2] Kong Soon Ng, Chin-Sien Moo, Yi-Ping Chen, Yao-Ching Hsieh. Enhanced coulomb counting method for estimating state-of-charge and state-of-health of lithium-ion batteries. Applied Energy 86 (2009) 1506–1511.

DOI: 10.1016/j.apenergy.2008.11.021

[3] R.E. Kalman, Trans. ASME 82 (1960) 35–45.

[4] G.L. Plett. Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs: Part 1 Background. Power Sources 134 (2004) 252–261.

DOI: 10.1016/j.jpowsour.2004.02.031

[5] G.L. Plett. Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs: Part 2 Modeling and identification. Power Sources 134 (2004) 262–276.

DOI: 10.1016/j.jpowsour.2004.02.032

[6] G.L. Plett. Extended Kalman filtering for battery management systems of LiPB-based HEV battery packs: Part 3 State and parameter estimation. Power Sources 134 (2004) 277–292.

DOI: 10.1016/j.jpowsour.2004.02.033

[7] C. Lin, Q.S. Chen, J.P. Wang. Improved Ah counting method for state of charge estimation of electric vehicle batteries(In Chinese). Journal of Tsinghua University (Sci&Tech) 46 (2006) 247–251.

[8] J.P. Wang, B.G. Cao, Q.S. Chen, F. Wang. Combined state of charge estimator for electric vehicle battery pack. Control Engineering Practice 15 (2007) 1569–1576.

DOI: 10.1016/j.conengprac.2007.03.004