Research On Modeling And Equilibrium Technology Of Power Lithium Battery Influenced By Temperature

In the "Energy Conservation and New Energy Vehicle Industry Plan(2012-2020)",it is clearly pointed out that by 2020,the production capacity of pure electric vehicles and plug-in hybrid vehicles will reach 2 million units,and the cumulative production and sales volume will exceed 5 million units.The goal of the simultaneous development of the hydrogen energy industry for automobiles and vehicles and the international market.The vigorous promotion and development of national policies has set off a wave of research on electric vehicles.However,the safety and life time of in-vehicle power batteries in use are the main factors that restrict the popularity of electric vehicles.This paper focuses on the battery management system,focusing on two aspects of battery modeling and equalization circuit design,and combines theory with reality by designing a balanced acquisition board.The lithium ion simulation model and the battery pack equalization simulation model were built by Matlab simulation tool to verify the accuracy of the modeling and the rationality of the equalization strategy.In this paper,lithium iron phosphate battery was selected as the research object.Firstly,the power characteristics of the battery at different temperatures were used to summarize the variation of model parameters at different temperatures.Combined with the classic Thevenin model,a dynamic battery model considering temperature effects was proposed.Based on this battery model,an active equalization scheme for energy transfer of adjacent batteries is designed.Further design and build an experimental platform for testing.The experimental platform includes: battery voltage,current,and temperature acquisition circuits.The data collected by the experimental platform is used as the basis for battery pack equalization and safe operation of electric vehicles.Finally,a battery model considering temperature and a balanced circuit model are designed in Matlab.Compared with the common model,the newly proposed model is superior in accuracy and equalization speed,and is more suitable for simulating the working characteristics of physical batteries.The rationality of the designed equalization scheme.After that,experiments were carried out,including: voltage acquisition experiment,current collection experiment,temperature acquisition experiment,battery SOC estimation experiment.The compariso method results show that each acquisition circuit and equalization strategy scheme are feasible,and the SOC estimation accuracy also meets the requirements.Figure [81] Table [13] reference[63]...