Research On Pure Electric Vehicle Lithium-ion Battery Management System

The burning of fossil fuels was taken by traditional vehicle as the power supply,not only caused a worldwide shortage of resources, even bring great pollution to theenvironment. The emergence of electric vehicle greatly reduced the problem ofresources and environment. As a key technology of the pure electric vehicle, thebattery management system plays a very important role in improving the batteryperformance and extending battery life. Battery management system takes monitoron the working state of the battery during the whole process, collects the workingstate data of the battery, including the battery voltage, current and temperature data;it can also realize the estimating function about the battery SOC (State of Charge).Taking lithium iron phosphate battery of lithium ion battery as the researchobject, conducted the design of battery management system experimental platform.The purpose is to collect the working state information in the battery workingprocess, to enhance the working performance of the battery, to extend the recyclinglife of the battery.Firstly, the working principle of the lithium-ion battery were introduced, todetermine the factors which can influence the battery SOC, work performance andrecycling life, and introduce several different estimation methods of the battery SOC.Secondly, design the hardware and software of the battery management system.The design of the battery management system hardware uses TMS320F2812ascentral control unit chip, design the collecting circuits of battery voltage, current andtemperature, and the interface circuit of the CAN bus. To take the CCS3.3softwareas development environment, writing the subroutines including the system mainprogram, initialization, data collecting, A/D conversion and CAN communicationmodule.Finally, build the experimental platform of battery management system, taking charge and discharge experiments under different conditions on the battery,collecting the relevant data, drawing the SOC curve of the battery, and analyzing theexperimental results. The experimental results show that, the battery managementsystem which is designed is practical and reliability, can achieve highaccuracy battery state information collection and the communication between theCAN communication module and the principal computer.