An ECM-PSO based optimal charging current pattern searching for Li-ion batteries

Abstract

Abstract. EV battery charging is growing in importance as it has a direct influence on the EV performance. Multistage Constant Current (MCC) charging strategy is an effective rapid charging method. This paper proposes an ECM-PSO algorithm to search for the optimal current pattern of the MCC charging strategy. The MCC charging model is built according to the Li-ion battery equivalent circuit model, and the object function for the ECM-PSO optimization was formulated and the optimal current pattern of the MCC charging method was obtained through the ECM-PSO algorithm. The experimental result shows that the obtained current pattern is capable of charging the batteries to 87.7% of the rated capacity within 36.5 min. Compared with the conventional CC-CV charging method, the proposed charging strategy has a performance improvement of 60.3% in charging time reduction, and the average temperature rise during the proposed MCC charging process is 0.5 ℃ lower than the CC-CV charging method.