Effect of the deadtime on the ZVS in phase-shifted full-bridge DC/DC converter for electric vehicle application

Phase-shifted full-bridge (PSFB) DC/DC converter with synchronous rectifiers, which has the advantages of high conversion efficiency, high power density, and low electromagnetic interference, is a widely used topology for power conversion in the electric vehicle. But it is not easy to achieve zero voltage switching (ZVS) operation under light load condition because the energy in leakage inductance is insufficient. This paper proposes that ZVS operation is also closely related to the deadtime of lagging-leg switches. Analysis and optimized design is presented. Feasibility and effectivity are verified with simulation and experimental results of a prototype converter.