A Dual DC-Bus Integrated DAB Converter With Voltage Match Control for Wide Voltage Range Applications

This article proposes a dual dc-bus integrated dual active bridge (DAB) converter with voltage match control for wide voltage range applications. The proposed converter has a feature of dual dc buses, one of which is adjustable while the other is always clamped by the input source. An auxiliary inductor is added to transmit power between the dual dc buses. The voltage of the adjustable dc-bus is regulated to match the voltages between two sides of the series inductor. With the voltage match control, the root mean square (rms) value of the transformer current is reduced and all switches can achieve theoretical full load range zero voltage switching (ZVS) operations. Furthermore, the auxiliary inductor processes only a portion of the main power and operates in continuous conduction mode (CCM), resulting in low losses and small size. Consequently, the efficiency is optimized over a wide voltage range. The working principle, working characteristics, and design considerations are introduced in detail. Finally, a 1 kW laboratory prototype is built to verify the theoretical analysis. The peak efficiency of the prototype is 96.8% and the efficiency over a wide range of voltage is always above 90%.