Temperature dependent circuit-based modeling of high power Li-ion battery for plug-in hybrid electrical vehicles

To increase the electrical range of plug-in hybrid electric vehicles (PHEVs)/electrical vehicle (EVs), interest of researchers is increased significantly in Li-ion batteries as these are leading energy storage component. An accurate modeling of battery with knowledge of all its parameters will optimize the vehicle performance. For achieving better performance of vehicle, correct knowledge of state of charge (SOC) of battery is required. Battery characteristics get affected due to several parameters such as temperature, aging and cycle life etc. In this paper, a new expression of temperature dependent battery SOC is developed and effect of temperature variation on this is investigated. Change in temperature influences the current, open circuit voltage (OCV), internal resistance and capacity of battery which contribute in SOC estimation. To demonstrate the real time characteristics and behavioral change of battery with respect to temperature; two dynamic battery models using MATLAB/SIMULINK environment are implemented. Influence of temperature on OCV, resistance, capacity and SOC is observed and simulation results are compared with recent studies. The simulation results show the effectiveness of models proposed.