Parameter Identification of Lithium Iron Phosphate Battery Model for Battery Electric Vehicle

Abstract The third-order equivalent circuit model of battery electric vehicle lithium iron phosphate battery has been established. According to the characteristics of lithium iron phosphate battery in charging and discharging process, the data of open circuit voltage change during battery test were used to identify the third-order equivalent circuit model parameters. The joint simulation of lithium iron phosphate battery discharging based on NEDC operating condition was carried out by using MATLAB and ADVISOR software. The lithium iron phosphate battery was tested on the power battery test platform. The results show that the maximum relative error between the value of simulation and test is small. The trend of the simulation and test curve is in good agreement. Moreover, the characteristics of the lithium iron phosphate battery are described well by the third-order equivalent circuit model. The results demonstrate that the third-order equivalent circuit model has high accuracy.