Dual-Active-Half-Bridge Converter With Output Voltage Balancing Scheme for Bipolar DC Distribution System

Conventional dual-active-bridge dc-dc converters require a dedicated voltage balancer or feedback control when they are used for a bipolar LVdc distribution system. This article proposes a dual-active-half-bridge (DAHB) converter with voltage balancing. The proposed converter is composed of a conventional DAHB converter with an additional inductor and capacitor voltage balancer (LCVB). The LCVB is added between the transformer and the output of the DAHB converter. Although the LCVB increases the switch current, it can balance the two output voltages without additional active switching device and feedback control under unbalanced load conditions. In addition, compared with the conventional DAHB converter, the LCVB can increase the zero-voltage-switching range of the DAHB converter and has no detrimental effect on the operation modes and performances. A 2.8-kW prototype was built and tested to verify the performances of the proposed converter.