A current-tripler-rectifier PWM ZVS three-phase full-bridge DC/DC converter with Y-Δ connected transformer

In order to decrease the current stress of switches in high power condition, a current-tripler-rectifier ZVS three-phase full-bridge DC/DC converter based on PWM control strategy is proposed in this paper. Three-phase full-bridge structure in primary side and current-tripler rectifier in secondary side are applied. The converter is preferred to be applied in high power, high input voltage, large-output-current condition. As three-phase interleaved structure is adopted, not only current stress of switches decreases, but also the frequency of input and output current ripple increases to three times of switching frequency leading to smaller filter. Based on PWM, all switches achieve ZVS. It´s quite easy to achieve ZVS for lower switches of the bridge leg since the energy comes from output filter inductor. While the energy of upper switches achieving ZVS comes from leaking inductors of two phase transformers, it´s easier to achieve ZVS compared with lagging leg switches of phase-shifted full-bridge converter. A prototype with the input 360V & output 48V/42A is built and the results are given based on the experiments.