A Family of Discontinuous PWM Strategies for Quasi Z-Source Nine-Switch Inverters

This paper proposes a new family of discontinuous PWM strategies to control the quasi-Z-source nine-switch inverters (qZS-NSI). The presented provide buck and boost inversion capabilities, suitable for common-frequency different-frequency modes operation. Accordingly, two different shoot-through (ST) approaches are introduced compared. first approach uses three-leg ST, while second single-leg ST reduce number switching commutations, therefore minimizing losses. Both can be implemented using simple-boost (SB) maximum (MB) methods. operating principles, performance criteria, modulator each scheme introduced. Compared conventional technique same output voltage gains, proposed schemes ensure continuous input current with minimum ripples, stresses on devices capacitors could reduced in MB schemes. Moreover, effective frequency upper lower switches all is fixed by 1/3 from qZS-NSI, only middle switches. modulation digitally tested LAUNCHXL-F28379D DSP. feasibility confirmed via simulation experimental results, which show good agreement theoretical analysis. applied other types Z-source NSIs.