MHz駆動電流形スナバレスソフトスイッチングDC-DCコンバータ

抄録

This paper presents a novel current-fed step-up DC-DC converter that is suitable for the front-end high-frequency link DC-DC converter (DC-X) in a grid-tied inverter of a fuel cell interface. The proposed DC-DC converter features the snubberless zero current soft-switching (ZCS) commutation with high-frequency switching by adopting quasi-resonance and parallel load resonance; the multi resonance while minimizing the number of additional circuit components. The switch-mode transitions of the proposed DC-DC converter are explained in detail for revealing the principle of snubberless ZCS due the multi resonance. In order to analysis the proposed DC-DC converter more precisely, a time-domain analysis is employed to examine the high-order harmonics in the three-level stepwise voltage of the quasi-resonant high frequency inverter, which is superior to a conventional sinusoidal AC analysis. The effectiveness of the proposed converter and the analytical strategy is demonstrated by comparing the theoretical and simulation results, after which the feasibility is verified by experiment of a 1 MHz-55 W class prototype with Gallium Nitride (GaN) high-electron-mobility-transistor (HEMT).