An Improved Control Scheme for Single-Phase Auxiliary Resonant Snubber Inverter

The traditional variable-timing control of auxiliary resonant snubber inverter (ARSI) realize natural zero-voltage-switching (ZVS) of main switches in every switching period to reduce the conduction loss. However, this method leads to failure of ZVS in the light load condition. Therefore, this paper proposes an improved control scheme with two modes for single-phase ARSI to achieve ZVS from zero load to full load. In heavy load mode (HLM), half of main switches are turned on at ZVS condition by using the output current to reduce the conduction loss. In light load mode (LLM), all the main switches achieve ZVS with the conduction of resonant branch to solve the problem of the failure of ZVS near zero load current. Besides, the auxiliary switches can operate at zero-current-switching (ZCS) condition. The proposed control scheme was first verified in the simulation and then validated in the experiment with an inverter prototype. The results show that the proposed control scheme can make main switches achieve ZVS from zero load to full load.