Research And Design For The BMS System Of Lithium Batteries In The Electrical Vehicle

The electric vehicle is a kind of new traffic tool,which develops in the environment of global warming,environmental pollution and energy crisis.It becomes an important research area of the car industry because of its high efficiency,no emissions and small noise.Battery Management System(BMS),which is an important link in connecting Battery pack,vehicle System and motor,has become the core technology link of many new energy vehicle enterprises at home and abroad.In the process of tandem use of lithium batteries in electric vehicles,such problems as overcharge,over discharge,high temperature and inconsistency between single batteries are involved.The battery’s cycle life and the driving safety of electric vehicles will be seriously affected if the battery cell is not managed.The main contents of this paper include the following four aspects: first,the analysis of the structure,principle,characteristics and inconsistencies of lithium battery.Second,the introduction of some commonly used SOC(Sate of Charge)estimation methods and detailed analysis of coulometer method used in this project.Third,this paper uses the STM32F103RCT6 of the ST Microelectronics as main control chip and ADI company’s dedicated battery management chip AD7280 A for battery information acquisition and balanced management to design a battery management system which can collect the information of battery voltage,current and temperature.At the same time,the system also has the SOC estimation,overcharge and over discharge warning,battery thermal management and balancing functions.Fourth,according to the BMS system test through experiment with 12 lithium iron phosphate batteries and the experimental data analysis,the results show that the design of BMS system can realize the battery detection and management of information.