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Abstract
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Selective harmonic elimination (SHE) in multilevel inverters is an intricate optimization problem that involves a set of
nonlinear transcendental equations which have multiple local minima. A new advanced objective function with proper weighting is
proposed and also its efficiency is compared with the objective function which is more similar to the proposed one. To enhance the
ability of the SHE in eliminating high number of selected harmonics, at each level of the output voltage, one slot is created. The SHE
problem is solved by imperialist competitive algorithm (ICA). The conventional SHE methods cannot eliminate the selected
harmonics and satisfy the fundamental component in some ranges of modulation indexes. So, to surmount the SHE defect, a DC-DC
converter is applied. Theoretical results are substantiated by simulations and experimental results for a 9-level multilevel inverter.
The obtained results illustrate that the proposed method successfully minimizes a large number of identified harmonics which
consequences very low total harmonic distortion of output voltage.
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