A novel approach for state of charge estimation based on adaptive switching gain sliding mode observer in electric vehicles

• Published in: Journal of power sources Vol. 246; pp. 667 - 678
• Main Authors: Chen, Xiaopeng, Shen, Weixiang, Cao, Zhenwei, Kapoor, Ajay
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 2014
• Subjects: Applied sciences; Charge; Direct energy conversion and energy accumulation; Electric batteries; Electric charge; Electric vehicles; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; Gain; Ground, air and sea transportation, marine construction; Lithium batteries; Mathematical models; Observers; Road transportation and traffic; Sliding mode; Switching; Lithium ion batteries; Adaptive switching gain sliding mode observer; Sliding mode; Variable structure system; Alkaline storage battery; Battery management system; Secondary cell; Electric vehicle; Switching; Lithium battery; Battery equivalent circuit model; Lithium-polymer battery; Equivalent circuit; State of charge; Electrical impedance; Electrochemical impedance spectroscopy
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2013.08.039

In this paper, a novel approach for battery state of charge (SOC) estimation in electric vehicles (EVs) based on an adaptive switching gain sliding mode observer (ASGSMO) has been presented. To design the ASGSMO for the SOC estimation, the state equations based on a battery equivalent circuit model (BECM) are derived to represent dynamic behaviours of a battery. Comparing with a conventional sliding mode observer, the ASGSMO has a capability of minimising chattering levels in the SOC estimation by using the self-adjusted switching gain while maintaining the characteristics of being able to compensate modelling errors caused by the parameter variations of the BECM. Lyapunov stability theory is adopted to prove the error convergence of the ASGSMO for the SOC estimation. The lithium-polymer battery (LiPB) is utilised to conduct experiments for determining the parameters of the BECM and verifying the effectiveness of the proposed ASGSMO in various discharge current profiles including EV driving conditions in both city and suburban.