Design Of Battery Management System Based On Electrochemical Model Of Lithium Battery

The widespread use of traditional fuel vehicles has aggravated the shortage of fossil energy and environmental problems.Electric vehicles have become a trend to replace traditional fuel vehicles,and all countries in the world are actively developing electric vehicles.The development of battery technology is one of the important factors to promote the development of electric vehicles.As a bridge between electric vehicles and power battery packs,battery management system plays an important role in prolonging battery life,increasing battery usage and ensuring safe and reliable operation of batteries.It has important economic and practical value to carry out relevant research.In this paper,the research and design of battery management system for lithium iron phosphate batteries widely used in electric vehicles are carried out.Firstly,the electrochemical principle of lithium iron phosphate battery,the important parameters to characterize the battery state and the charge-discharge characteristics were analyzed,and the electrochemical model was established.On this basis,the method of combining extended Kalman filter(EKF)and time integration(AH)is used to estimate SOC of battery charged state,which improves the accuracy of SOC estimation compared with traditional algorithm;SOH estimation of battery health state is carried out by Elman neural network;battery balance research is carried out by non-energy consumption strategy to improve the efficiency of battery battery charges,which is conducive to delay.Long battery life.MC9S12XE Freescale chip is selected as the control chip to design the battery management system.LTC6803 chip is used as the important characteristic parameters such as temperature,battery voltage and battery current for slave chip to detect the battery management system.The SOC and SOH estimation of thebattery and the judgment of related faults are completed by using the collected battery characteristic parameters.At the same time,the main control board sends out PWM signal to control the turn-on and turn-off of MOS transistors in the equalization circuit to ensure the balance of the working status of the two adjacent batteries.Finally,the CAN bus communication circuit is designed.On the one hand,it completes the transmission of information instructions between the master control board and the slave control board,on the other hand,it realizes the exchange of information between the battery management system and the electric vehicle.The algorithm and strategy are simulated and analyzed by MATLAB/Simulink,and the simulation results verify the feasibility and accuracy of the algorithm strategy.The battery management system is tested and analyzed,and the test results show that the battery management system designed meets the requirements of the industry for the accuracy of parameter acquisition.