Design and Implementation of a High Power Dual-module Parallel Charging System

[[abstract]]This paper presents a high-power dual-module parallel charging system which consists of a power converter and digital control software. The power converter consists of an active power factor correction (APFC) circuit and a resonant voltage fed full-bridge converter (RVFFBC). The APFC circuit is used for AC/ DC conversion and power factor correction for improved power quality. The RVFFBC is used to provide stable power for charging the battery by converting the high voltage of the power stage to a lower value. The system software was designed by combining the power control loop into a voltage and current loop to achieve current sharing of the dual-module charging system and to overcome the effect of differences in hardware components. Finally, this paper demonstrates the implementation of a high-power dual-module charging system with a widely varying AC input voltage ranging from 85 ~ 265 Vac. Experimental results verified that the maximum power factor of the system and the Total Harmonic Distortion (THD) were 0.99 and 2.8% respectively. The proposed charging system possesses very high expansibility. The parallel dual-module output DC current of the system is 70 A and the total output power is 4 kW