The new formulation for the electrical modeling of the three-level converter combined with the new control strategy reveals the capability in mitigating the unbalancing between the capacitors bank voltages. The THD of the output current with the two-level converter and with the three-level converter have propensity to be decremented with the increment on the wind speed.
The ideal sinusoidal voltage waveforms on the grid gives as expected smaller values for the THD. lower than 5% limit imposed by IEEE-519 standard. in comparison with non-ideal sinusoidal voltage waveforms having a fifth harmonic. Hence. non-ideal sinusoidal voltage waveforms on the grid affect the current injected into the grid by the WEC. The fractional-order controller strategy provides better results comparatively with the classic controller in what regards the level of the first harmonic and the THD. The fractional-order controller strategy provides better results when comparing with the classical integer-order controller strategy in what regards a time-domain simulations performance by means of sudden grid RMS voltage decrease. The WEC with three-level converter for grid voltage with 15 % of fifth harmonic. the THD is lower than 5% limit imposed by IEEE-519 standard. Finally. the values of THD should not only be imputed as a responsibility of the WEC. but also of the electric grid due to the presence of an endogenous voltage fifth harmonic component.