A comparative analysis between the symmetric and the hybrid asymmetric nine-level series connected H-bridge cells inverter

This paper presents the comparison of two cascaded multilevel inverter, with phase-voltage of the nine levels and applied to drive an induction motor of 500 kVA/4160 V. Performance indices used in hereinafter in the comparison are semiconductors power losses, total harmonic distortion and first order distortion factor. The comparisons are developed in three ways; in the first comparison the switching frequency is found. It guarantees that the converters present the same efficiency. In the second comparison the objective is finding the maximum switching frequency that it is gotten in each topology. Finally, in the third comparison, the efficiency which both systems present the same output filter is found.