Parameters Identification of Solar Cell Batteries

Photovoltaics and wind energy cause instability of power grid due to their out put fluctuations. Battery energy storage system (BESS) is the current and typical means of smoothing solar power generation fluctuations. This paper will initially present a review of the several battery models used for battery energy storage system applications. Models will be discussed which takes into account the non-linear characteristics of the battery with respect to the battery’s state of charge. We identified the parameters of solar cell batteries using the method “parameter estimation tool” of simulink library. The selected mathematical models are the Macomber model and Thevenin model. In order to validate models, a comparison between results gotten by calculation with those by experimental data found by testing these batteries under different constant currents has been undertaken. This method allows us to know and predict the behavior of the battery in the applications of photovoltaic solar energy. We note easily that the correlation between measured data and those calculated by the Macomber and Thevenin models for ambient temperature of 25 °C is good and very encouraging, so these models have been chosen for the survey of photovoltaic system simulation.