Electric Vehicle Battery Experiment Modeling Study

As the feeble section of electric vehicle, power battery was the main obstacle of the industrialization of electric vehicle. Designing a sound battery management system was one of the key technologies of electric vehicles. It was known that the performance difference among different kinds of batteries and considerable individual difference among the same kind of battery had great influence on the performance of battery team and the whole capability of electric vehicle.Firstly, how to study the performance of battery discharging by experiment modeling was introduced. Experiment modeling was the fundamental research of the project appointed by Beijing science and technology committee (the project name is practical energy management system based on field bus for electric vehicles, contract No. 9550421000). Secondly, how to collect and deal with experiment signal was discussed. The configurations of system including static data collecting system and dynamic data collecting system were discussed next. By using the newly issued chip abroad applied in monitoring battery, the system had a simple configuration and sound ratio between performance and price.The study of experiment modeling about the discharging performance of power battery was emphasized. Experiment modeling was divided into static experiment modeling and dynamic experiment modeling. The static experiment model including voltage & ampere-time model and the model of the equilibrium of battery capacity when the battery was charged and discharged was discussed in detail. The latter was focused on how the discharging conditions including discharging intensity, intermission time and environmental temperature influenced the parameters of themath model. Through the method of experiment modeling, the performances of the four kinds of power batteries (Valve regulated lead-acid battery, Colloid Lead-Acid battery, MH-Ni battery and Lithium-ion battery) were compared. With hundreds of discharging tests, some significant results were gained.In addition, the application of experimental modeling of battery in designing BMS and estimating SOC was demonstrated briefly.