Abstract

For the generation of high quality AC voltage, multilevel inverters are used with adequate modulation techniques, which allow obtaining a waveform with many levels. In particular, in Cascaded H-Bridge inverters, it is possible to obtain a high number of levels, if the relationship of their DC voltages is asymmetric. This paper shows a modulation technique based on the minimization of the WTHD of the total AC output voltage, for a Cascaded H-Bridge of five cells, which generates an AC output voltage of 11 levels, with the above calculate the DC voltages and firing angles for a range of modulation index 0.0 < m < 1.0, obtaining the elimination of harmonics 3, 5, 7, 9 and 11, in addition to obtaining an AC output voltage at fundamental frequency that can be manipulated. Simulation results show that for m=1.0, 0.296% WTHD and 6.944% THD are obtained.