Citation:Junhui Li,Fengjie Gao,Gangui Yan,Tianyang Zhang,Jianlin Li.Modeling and SOC estimation of lithiumiron phosphate battery consideringcapacity loss[J].Protection and Control of Modern Power Systems,2018,V3(1):61-69[Copy] |
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Abstract: |
Modeling and state of charge (SOC) estimation of Lithium cells are crucial techniques of the lithium battery
management system. The modeling is extremely complicated as the operating status of lithium battery is
affected by temperature, current, cycle number, discharge depth and other factors. This paper studies the
modeling of lithium iron phosphate battery based on the Thevenin’s equivalent circuit and a method to
identify the open circuit voltage, resistance and capacitance in the model is proposed. To improve the accuracy of the
lithium battery model, a capacity estimation algorithm considering the capacity loss during the battery’s life cycle. In
addition, this paper solves the SOC estimation issue of the lithium battery caused by the uncertain noise using the
extended Kalman filtering (EKF) algorithm. A simulation model of actual lithium batteries is designed in Matlab/Simulink
and the simulation results verify the accuracy of the model under different operating modes. |
Key words: Lithium-iron battery, Battery model, Capacity fading, State of charge estimation |
DOI:10.1186/s41601-018-0078-0 |
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