An Internal AC Self-Heating Method Based on On-Board Charger for Lithium-Ion Batteries Preheating

Abstract

In cold climates, lithium-ion batteries have a significant drop of performance, which will cause the driving range of electric vehicles (EVs) drop substantially. Many heating methods have been proposed to heat cells. How-ever, external heating methods have widely applied to EVs which are low efficiency. Although internal heating methods are high efficiency, they don’t apply to EVs due to complex control or external power supplies demand. Therefore, this paper proposed an internal ac self-heating method based on On-board Charger (OBC) without severe application demands. This method integrates OBC with ac heating circuit, which is controlled by two PWM signals. In addition, a battery thermoelectric coupling model in frequency do-main is established in MATLAB/Simulink. The simulation results show the higher frequency of ac current, the faster rising speed of battery temperature at the same RMS value.