Isolated zero-voltage-switching DC-DC converter with high voltage gain

An isolated zero-voltage-switching (ZVS) DC-DC converter with high voltage gain is proposed in this paper. In the proposed converter, two conceptually identical DC-DC converters are merged. To obtain high voltage gain, the output stages of two converters have voltage doubler structure and they are serially connected. An active clamp circuit is adopted to clamp the switch voltages and obtain ZVS operation of the switches. Thus, the switching losses are reduced. Moreover, the output diode currents are controlled by the transformer leakage inductances and the reverse-recovery problem of the output diodes is significantly alleviated. Due to the voltage doubler structure and the serial connection of the output stages, the voltages across the output diodes are confined to half of the output voltage. Steady-state analysis and experimental results for the proposed converter are also presented.