Selected harmonic minimization in 3-phase 11-level switch-switch multilevel inverter using artificial gorilla troops optimization algorithm

Abstract A key challenge in designing 3-phase multilevel inverters (MLIs) is determining the switching angles that produce a low THD output voltage waveform. This work proposes an AGTO-SHMPWM technique for determining the switching angles, aiming to minimize low-order harmonics while achieving the desired fundamental harmonic. MATLAB analysis shows that the AGTO method achieves significantly lower objective function ( OF ) values, as low as 10 – 32 , compared to the GA and GOA methods. Cumulative distribution function analysis reveals that the AGTO method has a 38% probability of achieving an OF ≤ 10 – 30 , while the GA and GOA methods have a 0% probability. These results demonstrate that the AGTO method is more capable of thoroughly exploring the optimization solution space. PSIM simulation confirms that the switching angles computed using the AGTO method, when applied to a 3-phase 11-level switch-switch MLI (S2MLI), can produce sinusoidal-like staircase voltage waveforms with minimized V 5, V 7, V 11 and V 13 harmonics while achieving the desired fundamental voltage. The phase and line-to-line voltage THDs, when the S2MLI is operated at M idx of 0.80, are 7.93% and 5.55%, respectively, which are consistent with those predicted by MATLAB analysis.