Optimized Design for Complete ZVS Operation in Phase-Shift Full-Bridge DC-DC Converter with Series-Connected Transformers

This paper proposes an optimized design for complete zero voltage switching (ZVS) operation of the phase-shift full-bridge DC-DC Converter with series-connected transformers. This topology extends the ZVS range at light load, compared with the standard phase-shift full-bridge Buck topology, by exploiting the energy stored in the transformer’s magnetizing inductances. However, at full load, the ZVS condition still requires a suitable leakage inductance, which reduces the effective duty-cycle. A design procedure is proposed that allows a complete ZVS operation without relying on the transformer’s leakage inductance, which can be thus minimized. Experimental results highlight the effectiveness of the proposed design.