Dual active bridge (DAB) converters have been widely employed in power conversion systems due to the bidirectional power transfer capability, galvanic isolation, and high efficiency. In conventional DAB configurations, achieving zero-voltage switching (ZVS) across the full-load-range has been a challenge, which can only be realized when the voltage conversion ratio is close to unity. To address this limitation, a 2-level to 3-level DAB topology is investigated, where the primary side uses an H-bridge and the secondary side adopts an active neutral point clamped (ANPC) half bridge. This DAB topology not only achieves full-load-range ZVS at a conversion ratio of around 2:1 but also enables power conversion between low voltage and high voltage. In this digest, analytical derivations are carried out for each resonance process using non-ideal switches, leading to explicit current conditions that quantitatively specify ZVS from light load to full load. The analysis is further supported by experimental validations with 200 V dc input, 450 V dc output, and a transformer turn ratio of 1:1, corresponding to a voltage conversion ratio of approximately 2:1.
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