Research On Smart Battery System For Electric Vehicle

In order to solve the energy crisis and mitigate global warming, many countries pay attention to energy conservation and low-carbon economy. Electric vehicles use electricity to drive, and can reduce carbon dioxide emissions or reach zero emission. So electric vehicles get many states'attention and develop fast. Because of its long life, good safety performance and low cost, LiFePO4 battery has become an ideal power source for electric vehicles.This paper studies the operation principles and characters of LiFePO4 battery, and analyzes the problems needed to solve when using LiFePO4 battery in practice. On this basis, this paper studies the SOC estimation and correction strategy, balance control strategy, thermal management strategy, discharging control strategy and charging control strategy of LiFePO4 battery. Finally, by combining LiFePO4 battery and BMS, this paper studies the implementation of smart battery system. Hardware has complete structure and circuit. The control strategy of LiFePO4 battery is embedded in the software. Smart battery system can fulfill the task of battery measurement, management and protection, and can provide battery information completely, and control charge and discharge efficiently.The smart battery system has been used in electric cleaning vehicle in Beijing. The result shows that the system can ensure the battery safety and reliability, and guarantee electric cleaning vehicles operation stability.