An asymmetrical multi-level dual-input dual-buck inverter for multi-source interface applications

A novel dual-input dual-buck inverter (DIDBI) is presented to interface a low voltage DC source, a high voltage DC source and an AC load simultaneously. The presented DIDBI allows a low voltage DC source, e.g. low voltage bus, battery and renewable source, to supply power to the AC load directly, even though the voltage of the low voltage DC source is lower than the peak amplitude of the output AC voltage. Therefore, the conversion stages can be reduced to improve the conversion efficiency. In addition, the two DC sources provide multiple voltage levels for the inverter, which is benefit for reducing the switching losses and size/volume of filter inductor. The concept, topology, operation and modulation of the DIDBI are analyzed in detail and verified with experimental results.