An Adaptive Combination of Nine-switch Inverter Applications using Level- and Phase-shift Space Vector Duty-cycle Modulations

Abstract

ABSTRACT This paper presents the proposed level-shift and the phase-shift duty-cycle modulations, which are based on the continuous carrier-based space vector pulse width modulation (SVPWM) via the ac and dc components injection technique, for an adaptive combination of nine-switch inverter applications. The dual modulation techniques are selected to overcome the output voltage distortion of the nine-switch inverter caused by the cross-over of the duty-cycle modulating signals, due to its existing shifted phase of the ac component and shifted level of the dc component. The mathematical models of the ac component injection design for the phase-shift technique and the dc component injection design for the proposed level-shift technique were analyzed to carry out the primary drawback avoidance, covering both variable frequency and constant frequency modes. Simulation results are executed on a dominant adjustable speed drive load cooperated with a standalone load to evaluate the dual technique abilities, responding good dynamic- and steady-state performances. Keyword: Nine-switch inverter, Level-shift duty cycle modulation, Phase-shift duty cycle modulation, Carrier-based space vector pulse width modulation (SVPWM), Cross-over modulation