Research On SOC Estimation And Range Of Electric Vehicle Based On Simulink

The new energy electric vehicle is the strategic commanding height of the future automotive technology,and the power battery is the power source of the electric vehicle,which take the most important core in the electric vehicle technology.The perfect test evaluation method for the power battery science is to improve the driving range of the electric vehicle.It is crucial to study and promote the development of industrial innovation.The United States,the European Union,Japan government agencies as well as the world's major electric vehicle companies and scientific research institutions have invested a lot of research on this,and achieved certain results.However,there are many factors that affect the estimation of the SOC of the electric vehicle power battery.There are problems of insufficient accuracy,poor robustness,and being susceptible to external factors in the complex model.The complex model has the disadvantages of time-consuming calculation and numerous parameters,which are not easy to use in actual vehicles.This paper focuses on the estimation of power lithium-ion battery SOC and the battery life of pure electric vehicles.First of all,this paper expounds the working principle of lithium-ion battery,introduces six kinds of classical SOC estimation methods such as discharge test method and open-circuit voltage method,and analyzes the advantages and disadvantages of each estimation method.This paper highlights the advantages of the fusion algorithm based on the accurate battery model of unscented Kalman filter modified amian integration results in SOC estimation.Then,for each parameter in the battery model is dynamically changing characteristics,this paper designs the HPPC pulse discharge experiment,and established the second-order RC model and circuit mathematical model of the lithium-ion battery.In this paper,we designed the HPPC battery pulse charge/discharge experiment in MATLAB and combining the model equations,the parameters of the single temperature model and the multi-temperature model were identified offline.The influence of temperature and different SOC on the model parameters was analyzed.Finally,in order to solve the problem that the estimation accuracy depending on the bias caused by the initial value of the SOC,this paper proposes a fusion algorithm based on the accurate battery model of the unscented Kalman filter correction and the AH integration method to simulate the SOC of the lithium-ion battery.On the basis of the sub-basis,through the vehicle performance simulation platform,The performance of the vehicle was simulated under four different cycle conditions,and the cruising range under different operating conditions was analyzed.The method is closer to the actual level in the estimation of the driving range of the electric vehicle.The research in this paper has reference significance for the calculation of the cruising range.