Comprehensive classifications and comparisons of different modulation schemes for Z-source inverter

Z-source inverter introduces a unique impedance network between the dc source and inverter bridge. It boosts the input voltage by utilizing shoot-through (ST) states and provides a competitive single-stage approach for DC to AC power conversion. With regard to the unique circuit and operation mode, various modulation schemes including constant boost control, maximum boost control with different ST insertion approaches are proposed. This paper makes the classifications of existing modulation schemes, and then the comprehensive comparisons of them in aspects of power device requirement, passive device requirement, conversion efficiency and control loop design are implemented to reveal the advantages and disadvantages. Simulations and comparisons are conducted to verify all the theoretical findings.