Estimation Of SOC Using Kalman Filter Algorithm And Research On Battery Management System

With the development of science and technology,people need a new environmental environmental protection technology to replace the traditional energy consumption.Therefore,the new energy,which is led by lithium-ion battery,is chosen by people because of its own advantages of high specific energy,high specific power,safety and environmental protection.In this paper,a domestic rated capacity of 3000 mAh 18650 battery as the main research object,in order to improve the battery SOC estimation accuracy and battery acquisition module accuracy,at the same time find a good heat dissipation structure to analyze the heat dissipation of the battery pack.The main work of this paper is as follows:The current development of electric vehicles,the research background,significance and development prospects of conventional battery SOC estimation methods and battery heat dissipation methods are investigated,which lays a foundation for the battery SOC estimation in this paper.In this paper,Li-ion batteries with charge-discharge voltage of 4.2 V are studied.The basic working principle of the lithium-ion battery tested in this experiment is described,and the construction of the experimental platform is introduced,and a combined model is established to model the lithium-ion battery.Through the experiment,the parameters of the battery model are assigned.Carry on the capacity measurement experiment and the battery capacity influence factor experiment.The influence coefficients of discharge rate,temperature and cycle number were calculated.Based on the definition formula of SOC,the final modified formula is deduced to ensure the accuracy of the SOC estimation in this paper.The Kalman filter algorithm is introduced in this paper.The nonlinear Gaussian Kalman filter algorithm is used to estimate the SOC of the battery according to the fact that the battery is a nonlinear system.So this paper uses the sampling point Kalman filter algorithm.By determining the basic formula,then using MATLAB/SIMULINK to build the formula.Finally,the simulation results show that the accuracy and accuracy of the battery SOC estimation can be improved by using the Kalman filter algorithm of sampling points.The battery acquisition module is built.The Bernadi formula is used to solve the inner heat source of the battery,and the structure model with good heat dissipation performance is designed.At the same time,the single cell model of the battery and the air cooling heat dissipation model are established by CATIA,and the grid is divided by ICEM.Finally,the results are analyzed by FLUENT.