A High-efficient Battery Charging System for Electric Vehicle

Nowadays, automobile is facing the trend of electrification. Lithium-ion batteries is widely used as their power supplies. Lithium-ion battery has complex characteristics, as a result, Lithium-ion battery needs optimal charging strategies to make sure it is charged safely and efficiently. This paper focuses on development of a high-efficient charging method for lithium-ion battery. To test different charging strategies, the electric vehicle charging system consisting of a dual active bridge DC-DC converter and a Thevenin battery model is implemented. Multistage constant current charging (MSCC) and multistage constant current reflex charging (MSCC with reflex charging) were proposed. Compared with the traditional constant voltage constant current (CC-CV) charging method, MSCC can reduce 12% of the charging time and 1.1% of the battery loss; MSCC with reflex charging has a 10.45% and a 1.54% reduction of charging time and battery loss separately.