SOC Estimation Method And Management System For Lithium Battery Based On EKF

As the population of the world increases,the number of automobiles used in the world is increasing day by day,and the problem of energy and environment pollution is becoming more and more serious.In order to alleviate the problem of energy shortage and environmental pollution,many countries use electric vehicles as the future direction of automotive industry,and use electric vehicles instead of the original fuel vehicles for research and development.But in the process of practice,there are still many problems to be solved.The most important thing of there is the research of power battery and thedesign of battery management scheme.Nowadays,the basic tasks of the battery management system are:Battery information sampling,the equalization strategy,and the SOC(state of charge)estimation.The goal of the battery management system(BMS)is to make the battery run safely and steadily.Based on this goal,the SOC estimation and BMS based on lithium battery is designed.In this paper,the basic principle and internal characteristics of the lithium battery,the common SOC estimation method and the EKF estimation method of the design are analyzed.Meanwhile the charge state of the battery is simulated by MATLAB.Then in order to get battery infomation and realize the equalization function,we use STM32F103R8T6 as the master controller,and use LTC6804-2 as the front end analog collector.The main innovation of such design are as follows:SOC estimation method based on EKF,using LTC6804-2 which make the system run steadily,using the isolation circuit in the battery information sampling and signal communication units.Finally,the system has basically achieved the desired goal in the environment set up by the laboratory,and later it can join other functions such as high voltage detection.