Study On Software Design Of Electric Vehicle Battery Management System And Strategy Of The SOC Estimation

Owing to the explodation of the world's population, the amount of vehicles increases rapidly, which not only leads to increasing requirement of oil, but also makes the environment pollution more serious than ever before. Many contries spend much on the research of the electric vehicle to mitigate this status. The electric vehicle has been regarded as the new generation of the vehicle, and has attracted a great deal of attention. However, many problems are demanded to be solved in order to develop this kind of vehicle, and battery management system is one of the key technologies. The strategy of estimating the state of charge (SOC) is an important technology of the battery management system. The main goal of this paper is to research the strategy of the SOC estimation, and design related software for the system.At the beginning, the background of the project is introduced, and then some key technologies of the system are displayed. The definition of the SOC is given, and the frame of the paper is introduced.Secondly, the Li-Ion battery is introduced. The factors influencing the SOC are analysed and some models of the battery are given. Based on them, a state space model of the battery is proposed. The motheds to get the parameters of the model are discussed.Furthermore, some strategies of estimating the SOC are displayed and analysed. The method based on Extended Kalman Filter (EKF) is researched; simulations and experiments are given at the same time. An estimation method with weight factor is also discussed.In addition, the software of the battery management system is introduced. The main ideas of the sample board and main board's software design are analysed, and some float charts are also given.Simuliones and experiments indicate that the strategy of estimating the SOC proposed in this paper keeps an excellent precision and the software of the system runs well. They are likely to be put into practice.