Non-symmetrical SHE-PWM technique for five-level cascaded converter with non-equal DC sources

The paper proposes a new variation of the well-known selective harmonic elimination pulse width modulation (SHE-PWM) technique suitable for a high-power five-level cascaded converters with non-equal DC sources for utility applications. In this work, the switching angles are obtained when both the quarter- and half-wave symmetry are abolished. This changes the way the problem is formulated and different solutions and output waveform patterns are found and such solutions present no compromise. Different operating points are reported including different DC source combinations, different number of switching angles and different values of modulation indices. Simulation studies are presented to validate the theoretical findings and to confirm the robustness of the proposed approach.