Modeling Tool For Determination Of The Available Energy In Battery Storage Systems

In this paper is presented a Matlab/Simulink-based modelling tool for estimation of the State of Charge of Li-ion battery cells. The model is based on lookup tables, which makes it easy to implement in complex battery bank models, containing a large number of cells. The proposed model allows determining the state of the charge for any current based on interpolations. The developed model takes into account the variation of the battery usable capacity by discharging with different C-rates. The model is also applicable for cells with different capacities or different characteristics, according to experimental measurements or the producer datasheets. The model input variables are the discharge current of the cell and the initial State of charge and the outputs are the cell voltage and the cell State of charge. The developed model is validated by experimental results.