Recursive Method for Harmonic Elimination Problem in Multilevel Inverters

This paper develops a model of harmonics elimination in the output waveforms of the multilevel converters. In particular l-level cascaded H-bridges (CHB) inverters with
$l=2s+1, s=2^{n}$
, number of both dc sources and switching angles, are considered and an recursive model is proposed to determine the unknown switching angles as a function of modulation index. The procedure allows to eliminate
$n$
harmonics, arbitrarily chosen, and their multiple from output voltage waveform, imposing the amplitude of the fundamental harmonic.