Charge-discharge Characteristics And Intelligent Management Technology Of Vehicle Battery

The energy crisis, environmental pollution, and many other factors bring electric vehicles to the stage of history. The development of electric vehicles has the dual benefits of energy conservation and environmental protection, especially pure electric vehicles has the obvious advantages in the total conversion of energy efficiency and pollution emissions, electric vehicles is the future direction of development of the automobile industry. But Vehicle battery has become a bottleneck restricting in the development of electric vehicles, low energy density limits the mileage of electric cars, the shorten life of vehicles power battery pack and the drop of the safety performance hinder the industrialization of electric vehicles, as well as battery charging using a long time.In order to increase the mileage of electric vehicles, keep the vehicle power battery performance, using an effective and comprehensive monitoring and management of battery system is very necessary. The battery management system (BMS) has become the key to the commercialization of electric vehicles practical. The main functions of the battery management system include voltage monitor of single battery cells, temperature monitoring, voltage monitor of the battery pack, the estimate of the remaining capacity, and management of the battery balanced, battery safety protection and so on.But the core issue is the estimate of SOC, many features of the system, accurate estimate of the SOC is a premise for many features of the system to achieve. Battery management technology can prevent the unreasonable use of the group of batteries, can ensure long battery life and security of the battery, improve the efficiency when electric cars is running, keep battery capacity and improve energy efficiency.The first chapter describes the research background, including the research of the electric car, and the development of the power battery and battery management technology. The second chapter studies charge-discharge characteristics of the vehicle power battery by four experiments, selects the appropriate battery model and determines the method of the battery model parameters calculation. The third chapter focuses on several methods of SOC estimated and proposed compound estimated method for the phosphate iron lithium of SOC estimated. The composite algorithm is based on the EKF algorithm and combined with the open-circuit voltage method and the current integration method, and simulation results show the feasibility of complex algorithms. The fourth chapter deals with issues related to battery group applications and battery balanced battery. The last chapter focuses on battery management system hardware and software designing, as well as a LABVIEW monitoring interface of single battery voltage.