Analysis and Research on an Equivalent Circuit of LiFePO4 Battery Under a High Discharge Rate

This paper proposed a model parameter identification method for lithium iron phosphate batteries under high discharge magnification, used the identification results under 10 C discharge conditions instead of 30 C model parameters, and compared the actual output voltage observations of the LiFePO4 battery with the output voltage values of the established simulation model, which proved that the parameters under 10 C discharge conditions were still applicable under 30 C conditions, and the second-order RC model was more accurate than the first-order RC model. The results show that the proposed parameter identification method can solve the problem that the battery parameters identified by the Forgetting Factor Recursive Least Squares (FFRLS) at high discharge rate are not physically significant, and obtain a second-order RC model with higher accuracy, which provides a basis for subsequent state of charge (SOC) estimation of LiFePO4 battery.