Modeling And Simulation On NI-MH Battery In State Of Charge Of Electric Vehicle

With the fast development of the electric vehicle, the cost of battery and the life problem of the urgent need to be resolved. The power battery had not yet reached car energy demands. Research on SOC of battery, monitoring SOC of MH-Ni battery real-time in the operation of electric vehicles can maximize the use of extended battery life. The main work in this paper in allusion to the soc estimation on electric vehicle MH-Ni battery is as follows:First the characteristic of the MH-Ni batteries and the factors influenced on the SOC have been analyzed and different kinds of SOC traditional measuring methods have been compared such as electricity, resistance measurement, voltage measurement method, fuzzy logic, neural network method and the restoration of law. Multianalysis the influences among the estimating on SOC and the battery charge-discharge efficiency, the battery terminal voltage, the battery temperature characteristics and the self-discharge rate and so on through the experiments. Designed a series of charge-discharge experiments under different conditions, through a large number of experimental test data on MH-Ni battery charging and discharging process, compared the charge and discharge characteristics of the MH-Ni battery under different conditions, and the impact of environmental temperature on the MH-Ni battery discharge performance.The work is divided into two parts: the static model and dynamic model. According to gather the voltage of the battery, the temperature and the charging and discharging current historical data, establishes static mathematical model under the dissimilar conditions. Then according to the static mathematical models under various conditions, establishes dynamic mathematical model with the consideration of temperature effect and constantly changing. Finally simulating the dynamic model in the matlab, and then compared the result with the data measured by voltage measurement method. The result proved the model is accurate.The research on the subject has made some progress in the theory and the practice, and it has vital significance for further studies on SOC of MH-Ni battery.