An Enhanced Dual Active Bridge Converter with Full Domain ZVS by Utilizing a Simple Segment Control for Wide Voltage Range Applications

A dual-transformer-based enhanced dual active bridge (DAB) dc-dc converter for wide voltage range applications is introduced in this article. A power leg and transformer of the conventional DAB converter (CDABC) are split in two parts, leading to an expansion of the control freedom. Its wide voltage operating range does not rely on the small leakage inductor design and high transformer turns ratio. The root mean square value of the leakage inductor current is optimized with the ensuring of full domain zero voltage switching. The conduction losses and switching losses can be significantly reduced in buck mode compared to the CDABC. A simple segment control strategy with four control degrees of freedom is employed to avoid inrush from mode switching. The analysis and control processes are simplified, and the control loop is a simple closed voltage loop without the need for look-up table checking. The discussed converter and control strategy are verified by a 1.0 kW prototype.