A SEPIC Flyback DC-DC Converter with GaN Switching Device

A high-efficiency interleaved DC–DC converter based on SEPIC topology is developed in the paper, which can be used for micro photovoltaic inverter. Two flyback transformers in parallel connection can be controlled with single gallium nitride (GaN) switching power device. This is especially useful for the cost-down solution for high power situation with multiple flyback transformers in parallel connection. Using the single GaN switching device for double flyback transformers can suppress the output voltage ripple, while reduce the cost. In the paper, the detailed theoretical derivation on the novel topology is conducted. The simulation on the converter is carried out to verify the theoretical analysis. Finally, the topology is implemented on PCB board, experimentally showing the feasibility of the proposed converter.