An Algorithm for Harmonic Elimination in Three-Phase Multilevel Inverters

This paper considers three phase, l -level, cascaded H-bridges inverters with l = 2s + 1, where s = 2 n is number of dc sources, and proposes a procedure that imposes the amplitude of the fundamental harmonic and eliminates n arbitrarily chosen harmonics and their multiples from the output voltage wave-form. It works at fundamental switching frequency and returns the unknown switching angles through a simple mathematical expression that is function of the modulation index. A theorem proves the expression, then, both simulation and experimental results successfully validate the method.