Design And Research Of Lithium Iron Phosphate Battery Management System

With the depletion of energy and the deteriorating environment,the development of new energy vehicles to replace fuel vehicles has inevitably become a new trend.Among them,electric vehicles are an important part of new energy vehicles.Power batteries are also an important source of power for electric vehicles.Lithium iron phosphate batteries are superior to other power batteries in terms of performance.Therefore,research lithium iron phosphate battery management system are fit with background and practical meaning.The main function of the battery management system is to monitor and optimize the management of the power battery in the electric vehicle.The main research contents of this paper include:(1)Combining the actual application and functional requirements of the management system,researching and analyzing the structure,performance and use environment of lithium iron phosphate battery.A second-order RC equivalent circuit model is built.The simulation model is established in MATLAB and the battery data is obtained by charge and discharge experiments.Determination of parameters of equivalent circuit model by online parameter identification.(2)The research goal of lithium iron phosphate battery management system is proposed.Under the overall framework,each functional module is organized in a distributed structure,which is beneficial to management and maintenance.Using modular ideas to design software and hardware parts,mainly divided into acquisition module,equalization module,main control module,etc.;in battery data collection,the use of battery-specific chips and Hall sensors,can effectively improve the measurement accuracy,achieve battery voltage Real-time detection of current and temperature combined with the proposed strong tracking extended Kalman filter algorithm to estimate SOC;(3)Using battery SOC as the equilibrium criterion,comparing and analyzing the commonly used equalization circuit,and fitting the dedicated LTC3300-1 battery equalization chip design Bidirectional active equalization hardware circuit based on flyback transformer.The feasibility of the equalization circuit is verified in the built simulation model,and the equalization effect of the equalization strategy based on the single-cell SOC is verified.(4)The software design mainly focuses on the functions of each hardware module,the driving of the underlying device and the monitoring of the computer at the host computer.In this paper,the software design is divided into upper computer and lower computer.The lower computer mainly includes the acquisition module and the main control module software to realize the functions of data collection,analysis and processing.The upper computer software mainly realizes the monitoring function and provides visual interface operation.The experimental results of this paper show that the battery information recorded by the system can meet the actual accuracy and demand,and the equalization effect is remarkable.It can realize the management and monitoring of the battery pack composed of multi-cell lithium iron phosphate batteries.