Development of a battery energy loss observer based on improved equivalent circuit modelling

This paper proposes a new energy loss observer for batteries that has a good accuracy and low complexity. This observer can provide a support for battery management systems (BMS) in terms of predicting battery energy loss and/or battery internal temperature for given load profiles, and this enhances BMS capabilities for predictive and corrective actions. The typical observer requires an accurate battery model that represents accurately the internal resistance of the battery, and therefore battery modelling guidelines to produce a simplified equivalent circuit model (ECM) have been proposed. Experiments to validate the accuracy of the proposed model have been performed on a LiFePO4 (3.6V/8Ah) battery cell. The model parameter estimation has been achieved by fitting the model impedance to the battery impedance data obtained from electrochemical impedance spectroscopy. The energy loss estimation based on the proposed observer showed good accuracy with maximum error of ±2% under different load profiles operated within the targeted frequency range.

[1]  Zoran Stevic,et al.  Estimation of Parameters Obtained by Electrochemical Impedance Spectroscopy on Systems Containing High Capacities , 2009, Sensors.

[2]  Hongwen He,et al.  Evaluation of Lithium-Ion Battery Equivalent Circuit Models for State of Charge Estimation by an Experimental Approach , 2011 .

[3]  Mohamed Rashed,et al.  Assessing the accuracy of loss estimation methods for supercapacitor energy storage devices operating under constant power cycling , 2014, 2014 16th European Conference on Power Electronics and Applications.

[4]  Christian Fleischer,et al.  On-line adaptive battery impedance parameter and state estimation considering physical principles in reduced order equivalent circuit battery models part 2. Parameter and state estimation , 2014 .

[5]  Baojin Wang,et al.  Fractional-order modeling and parameter identification for lithium-ion batteries , 2015 .

[6]  Xi Zhang,et al.  Online Estimation of Electrochemical Impedance Spectra for Lithium-Ion Batteries via Discrete Fractional Order Model , 2013, 2013 IEEE Vehicle Power and Propulsion Conference (VPPC).

[7]  Federico Baronti,et al.  Modeling and online parameter identification of Li-Polymer battery cells for SOC estimation , 2012, 2012 IEEE International Symposium on Industrial Electronics.

[8]  Christian Fleischer,et al.  On-line adaptive battery impedance parameter and state estimation considering physical principles in reduced order equivalent circuit battery models: Part 1. Requirements, critical review of methods and modeling , 2014 .

[9]  J. Ross Macdonald,et al.  Impedance spectroscopy , 2006, Annals of Biomedical Engineering.