A Switching Scheme for Multilevel Converters with Non-Equal DC Sources

In this paper, we consider unequal voltage sources of integer multiple magnitudes, in cascaded H-bridge converters. The converter uses (m-1)/2 voltage sources and the proposed switching scheme render an m -level staircase waveform with equal steps. Since the resulting voltage levels are equal, the angles are determined for the complete elimination of (m-1) unwanted harmonics. The implementation of switching scheme, in single and three-phase configurations were simulated with Ansoft -Simplorer^reg and the frequency spectrum of the resulting waveform and its THD are shown to verify the results. Source and switch utilization were also evaluated.