Abstract
A constant-current constant-voltage (CCCV) charge protocol is commonly used for lithium-ion batteries. The dynamic characteristic of the constant-voltage (CV) charging current is discovered to be related to battery aging. In order to quantitatively describe the load current during the CV charging period, an equivalent circuit model (ECM) based on the resistor-inductor (RL) network is proposed in this paper. Motivated by the current expression derived based on the conventional resistor–capacitor (RC) network-based ECM, an RL network-based ECM is developed to characterize the CV charging current. Then, the parallel-connected RL networks are employed to improve the model fidelity. The test data of four lithium iron phosphate (LiFePO4) batteries in different aging states are employed to validate the proposed model. Comparative results show that the proposed 2nd-order ECM is the best choice, considering both the model accuracy and complexity. In addition, a simplified 2nd-order model is proposed, achieving a satisfactory accuracy with only three model parameters to be identified. Therefore, this model can be easily implemented in the battery management system (BMS).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.