Space vector and carrier-based PWM modulation schemes for maximum utilization of voltage sources of a nine-switch converter

The nine-switch converter (NSC) has been used in power quality conditioners and AC motor drives. However, it has not attracted much attention because of its amplitude, frequency and phase-shift limitations primarily due to the constraint on the modulation index of the converter. To satisfy the modulation constraint and correctly synthesize the desired voltages, `appropriate´ DC offsets must be added to the phase voltage commands. This study proposes space vector (SV) and carrier-based (CB) modulation schemes for the NSC that enable the realization of the converter full capacity. The mathematical formulation of the SV and CB pulsed-width modulation schemes are supported by MATLAB/Simulink simulations and validated with experimental results.