A Novel Soft-Switching Three-Phase Grid-Connected Quasi-Z-Source Inverter

A novel soft-switching three-phase grid-connected quasi-Z-source inverter is proposed in this paper. A branch including one resonant inductor, one resonant capacitor and two active switches, is added to the impedance network on the basis of the quasi-Z-source inverter topology. In addition, an improved space vector modulation (SVM) for the inverter is proposed. Thus, soft-switching operations of all switches could be realized in shoot-through states. The relevant switching losses and the THD of output waveform are reduced. The soft-switching characteristics are illustrated by the simulation results, which verify the theoretical analysis.