An Improved Discontinuous Space Vector Modulation Scheme for the Three-Phase Impedance Source Inverters

Among various modulation schemes that can be used with the three-phase impedance source inverters, discontinuous modulation schemes are seen to be worthwhile due to the resultant reduction in the switching losses. Depending on the employed method of achieving the shoot-through (ST) state, these discontinuous modulation schemes can be classified into two categories: three-phase-leg ST-based (3P) and single-phase-leg ST-based (1P) discontinuous modulation schemes. This paper considers the 1P maximum boost discontinuous space vector modulation (1P/MB/DSVM) scheme and improves it in terms of simplifying the gate signals generation and increasing the conversion efficiency for the same operating conditions. In this paper, the conventional and the improved 1P/MB/DSVM schemes are analyzed and compared, where the analysis and comparison are enhanced with simulation results using PLECS. Finally, a three-phase quasi-Z-source inverter (qZSI) prototype is utilized to verify the reported analysis and simulation results, demonstrating an improved conversion efficiency using the improved 1P/MB/DSVM scheme.