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

ABSTRACT 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.