Selective harmonic elimination for a 27-level asymmetric multilevel converter

This work presents a 27-Level Asymmetric Multilevel Converter that uses the staircase modulation. Optimized gating angles are proposed using the Selective Harmonic Elimination technique. Using the Fourier series the explicit harmonic equations are obtained and numerically solved. This allows to generate a resulting multilevel waveform without some specific low-order harmonics. The proposal is validated using software simulations in time and frequency domains.