A multiphase battery charger with pulse charging scheme

In this paper, a multiphase battery charger to improve the current utilization of the power supply unit (PSU) and the over voltage problem during negative discharging period is presented. According to output voltage specification of the PSU, maximum output power limitation, duty ratio and current ripples of the output inductor, the desired output voltage and maximum amplitude of the pulse charging current command can be determined for a small capacity sealed lead acid battery. The design procedures of the multiphase battery charger are detailed in this paper. Finally, three 7AH lead acid batteries were used to demonstrate the proposed multiphase pulse charging scheme. From simulation and experimental results show the over voltage problem of the PSU during negative discharging period that can be improved significantly