## 3 Verification with Simulated Results  
The numerically computed results and test of the low-frequency outputs of the circuit represented in Figure 3a need confirmation. The attractive and feasible platform for this verification is the computer simulation and practical results. Simulink/MATLAB is an attractive and perfect platform for the required validations of the carried research. In this environment, the variation in the harmonic factor of output voltage and the input current is examined to address their contradictory characteristics. Their FFT plots are also attained by modeling the circuit of Figure 3a. For this purpose, three output frequencies that include one-half, one-third, and one-fourth of input are considered for simulation results. The value of the input peak voltage and frequency are taken 200 V and 50 Hz, respectively. It has already been described that total output voltage rms and rms values of the required output voltage components depend on the magnitude scaling factor (\(k\)) of some selected output pulses. So, variations in the harmonics factor both for output voltage and input current are examined with respect to the magnitude scaling factor. The plots of Figure 7 illustrate the variation of the harmonic factors with respect to '\(K\)'. The detailed examination of these figures illustrates that harmonic factors of the output voltage and input current for one half frequency operation are low for the value of \(k=1\), as may be seen from Figure 7a. That is the case where amplitudes of all output half cycles are the same, helping to keep the harmonic factors of the output voltage and input current to 62% and 0%, respectively. For this output frequency, it is not possible to control the power quality of the output voltage by regulating the voltage of the selected half cycles. The harmonic factor for the output voltage as described in Figure 8a is nearly 74%, and this can be confirmed from the FFT plot in Figure 9a. The pulse voltage regulation approach only improves the harmonic characteristics for one-third and one-fourth output frequency. For these outputs, the harmonic factors of the output voltage are low for the value of \(k=0.5\), as can be seen from Figure 7b,c. However, the rate of decrement in the harmonic factors of the output voltage is low compared to the rate of rise in the harmonic factor of the input current once the value of magnitude scaling factor of the some selected half cycles of the output voltage is decreased from 1 to 0.5. In this situation, the harmonic factors of the input current are much improved once the value of \(k\) is approaching unity. Figures 8 and 9, respectively, illustrate the output voltage and their spectral information for various output frequencies. Here, the harmonic characteristics of the output voltage are tried to improve by setting the value of \(k=0.5\). This setting eliminates and lowers the source frequency harmonics from the output voltage for one-third and one-fourth output frequency, as may be found from the spectrum plot of Figure 9b,c respectively. However, this value of '\(K\) \begin{table}
\begin{tabular}{c c c c c c c} \hline \multirow{2}{*}{**Performance Indices**} & _f\({}_{o}\)=f\({}_{s}\)/2_ & _f\({}_{o}\)=f\({}_{s}\)/3_ & & _f\({}_{o}\)=f\({}_{s}\)/4_ & \\ \cline{2-7}  & **VA** & **NVA** & **VA** & **NVA** & **VA** & **NVA** \\ \hline Output voltage harmonic factor & 72\% & 63\% & 55\% & 68\% & 52\% & 70\% \\ Input current harmonic factor & 33\% & 0\% & 36\% & 0\% & 33\% & 0\% \\ Input current power factor & 0.94 & 1 & 0.93 & 1 & 0.94 & 1 \\ \hline \end{tabular}
\end{table} 
Table 1: Performance evaluation of output voltage and input current with and without voltage adjustment for various output frequencies. generates the line frequency harmonic (50 Hz) to approximately 40% of the fundamental component (25 Hz). There is also an increase in the amplitude of the other low-frequency harmonics which can be seen in Figure 9a.