Fast Charging Strategy Based on the Control-oriented Stress Model

Abstract

Lithium-ion batteries (LIBs) has been widely used in Electric vehicles (EVs) benefiting from their high-power density and long cycle life. Fast charging technology becomes a critical factor for EVs large-scale penetration in automotive market. This paper proposed an online stress-limited fast charging strategy based on close-loop control. A simplified single particle electrochemical model is established, based on which the computational complexity of stress model is greatly reduced. Proportional-integral (PI) observer is used for stress estimation, while proportional-integral-derivative (PID) controller is devised for stress limitation. Comparation results exhibit that the proposed fast charging strategy possesses a greater ability on stress constrain than the widely used multi-stage constant current charging protocol. Simulation results validated the applicability of the proposed strategy for arbitrary conditions.