Design And Research Of Lithium Battery Power Management System On Electric Vehicle

The environmental problems and energy problems that caused by traditional car are getting more and more sharp,the electric vehicles which are representative of the new energy vehicles has began to be widespread attention.Battery management system is the critical factor of the electric vehicle’s development.However the applicability on different working conditions of existing battery management system is poor,that results in low battery usage efficiency and reducing battery life.In order to solve this problem,the paper presents a battery management system based on C8051F040 which can switch the mode of battery pack.In the paper,four work are done.1.According to the operating characteristics of the lithium battery and the basic principles of embedded system development,this paper puts forward an overall plan on battery management.In the system,many battery burst modes are designed depending on road conditions,it can fast switch battery burst mode according to different working conditions.The system improves the accuracy of battery management.The paper developes an embedded hardware control platform based on C8051F040 microcontroller.The voltage acquisition program based on relays and shared A/D,the current acquisition program based on Hall sensor and the temperature acquisition program based on DS18B20 chip are determined.2.The software system partitions into a plurality of functional modules.TO Solve the problem of signal interference,data acquisition module based on filtering algorithm is constructed.According to the functional requirements of battery management system,battery pack module,fault management and record module,charge and discharge management module,SOC estimation module and human-computer interaction module are designed.3.The paper developed a SOC model that applies to lithium iron phosphate battery.SOC estimation method is the combination of ampere integration and open circuit voltage.And the validity of the model is validated by emulation program in MATLAB.4.The human-computer interaction besed on C8051 microcontroller and touch screen is developed,the experimental platform on battery management system is set up.The paper does experiment on the hardware circuit and major function module in order to validate the validity of the system.The test results laid the groundwork for the practical application of the battery management system.