Virtual stage pulse-width modulation technique for multilevel inverter/converter

The main theme of this paper is to present a new pulse-width modulation (PWM) technique for multilevel inverter/converter control, which provides more degrees of freedom for specifying the cost function than that for step modulation technique, for a given hardware. Therefore, the presented technique eliminates more specified low order harmonics without resorting to the increase of hardware. In comparison with the selective harmonic elimination PWM technique, for the same number of eliminated low order harmonics, the presented technique provides the advantages of both lower total harmonic distortion (THD) and less switching. Simulation and experimental results are presented to confirm the above-mentioned claims