Harmonic Elimination in Cascade Multilevel Inverter with Non Equal dc Sources using Genetic Algorithm

Abstract: The elimination of harmonics in a cascaded multilevel inverter by considering the un-equality of separated dc sources by using Genetic and Differential Evolutionary Algorithm and compared. Solving a nonlinear transcendental equation set describing the harmonic-elimination problem with non-equal dc sources reaches the limitation of contemporary computer algebra software tools using the resultant method. The proposed approach in this paper can be applied to solve the problem in a simpler manner, even when the number of switching angles is increased and the determination of these angles using the resultant theory approach is not possible. Theoretical results are verified by simulations results for an 11-level H-bridge inverter. Results show that the proposed method does effectively eliminate a great number of specific harmonics, and the output voltage is resulted in low total harmonic distortion.

Keywords: Genetic Algorithm (GA), multilevel inverter, selective harmonic elimination, unequal dc sources.