Optimization of Variable-Current Charging Strategy Based on SOC Segmentation for Li-ion Battery

摘要

This paper presents a variable-current charging strategy of Li-ion batteries. Since the battery characteristics vary with state of charge (SOC), it is more reasonable to divide the charging process based on SOC than on cut off voltage. We find an optimal charging pattern of the proposed strategy by Non-dominated Sorting Genetic Algorithm-III (NSGA-III). The Second-order Thevenin model of battery is established to simulate the charging process. Verification experiments are performed and results show that the obtained charging pattern has a temperature and loss reduction of 2.9 degrees C and 0.5% compared with constant current-constant voltage (CC-CV) strategy under the same charging time and capacity.