2014 IEEE Global High Tech Congress on Electronics (GHTCE 2014)

135 / 1971-01-01 00:00:00

An Active Equalizer For Serially Connected Battery Cells Based On Dc/dc Converter

equalizer; SOC; buck chopper circuit; buck-boost chopper circuit; balanced strategy; lithium-ion battery

This paper proposes an equalizer for serially connected battery cells based on buck chopper and buck-boost chopper topology circuit respectively. There are two different balanced strategies according to different states of battery. The strongest battery cell with the highest state of charge (SOC) is discharged by the buck-boost circuit when the battery is in charging state, and the weakest battery cell with the lowest SOC is charged by the buck circuit when the battery is in discharging state. This paper has completed three cycles balancing simulation experiments of discharging and charging to six serially connected lithium-ion battery cells. The discharging current under a certain UDDS and a constant charging current are used to complete the balancing experiments. The equalizer suggested in this paper is confirmed by the related experimental results.