An Efficient Resonant DC-Link Zero-Voltage Switching Inverter With a Single Auxiliary Switch

This brief devises a resonant DC-link zero-voltage switching inverter to achieve efficient operation of the inverter. A single auxiliary switch and few passive devices form simple auxiliary circuits on the DC-link of the inverter. When the auxiliary circuits are involved in the commutation process of the inverter, the DC-link voltage will get into the extremely short zero state in which main switches on the bridge arms can implement the function of zero-voltage switching, eliminating significant switching loss and achieving higher efficiency. In the meantime, the single auxiliary switch can also implement the function of zero-voltage switching. Besides, the voltage across all the switches is no more than the DC supply voltage, reducing the risk of over-voltage. The prominent characteristic of the inverter is the lowest number of auxiliary switches, which makes for the low cost and the simple control concerning auxiliary circuits. This brief elaborates each working state within a switching cycle. The experiment validation declares that switches implement the function of zero-voltage switching. The efficiency of the devised inverter is 99.1% under the rated state. Hence, the devised inverter is superior to other similar resonant DC-link inverters in terms of the efficiency.