Research on an Efficient Single-Phase Full Bridge SiC-Based Soft-Switching Inverter Without Auxiliary Switches

To enhance the operation efficiency of single-phase full bridge inverter, a novel single-phase full bridge passive SiC-based soft-switching inverter topology is proposed. The passive auxiliary network (PAN) with low energy consumption is used to make the main switch achieve wide range pseudo zero-current switching (ZCS) switch-on and pseudo zero-voltage switching (ZVS) turn-off to implement economic power saving. The absence of auxiliary switches in the PAN can render the control of the system simpler. The distinguishing feature of this soft-switching inverter is that each bridge arm's switches share a resonant cell (comprising an absorption inductor and an absorption capacitor), significantly reducing the additional components attached to the main switches. It utilizes a large-capacity electrolytic capacitor to act as a constant voltage source, constructing a passive and lossless energy feedback loop. This enables the reset of the absorption components, thereby improving the efficiency of the inverter. During the dead-zone mode, the load current can continue to flow through the PAN, which can reduce the negative impact of the dead-time state on the output current waveform of the proposed inverter. The experimental results on a 3-kW prototype with rated output power show that the switching device can realize soft-switching, and the distortion rate of the output current waveform of the inverter is improved.