## 4 Validation of the Suggested Circuit
### Results Obtained with Simulink Based Environment  
MATLAB/Simulink is one of the modern power tools employed for the analysis of the switching converter. That is why this platform is selected for simulation purposes. In this analysis, the peak value of the input voltage is taken as 150 V with an input frequency of 50 Hz. The load impedance value is 80 \(\Omega\), and the switching frequency for high-frequency transistors is selected at 25 kHz. The internal resistances of the switching transistor and diode are set to 0.08 \(\Omega\) and 0.006 \(\Omega\), respectively. The forward voltage of the diodes is assumed to be 1 V. A small value inductor of 500 \(\upmu\)H is inserted between the two converting blocks to avoid the possible shoot-through concern that may arise due to the inherent turn-off delay of the switching transistors operated in a complementary way. In summary, these parameters are also represented in Table 3.  
According to the control scheme as depicted in Figure 4, one signal controls the operating states of the two transistors, and the second switching signal that is in complementary form of the first signal controls the operating states of the other two transistors. These switching signals govern the operating states of the transistors in such a way that if the conduction of two transistors non-invert the input at the output, then the conduction of the other two transistors inverts the input voltage at the output as shown in Figure 7a. It depicts that the input voltage at the output is alternatively non-inverted and inverted during the positive and negative half cycles of the input voltage. The frequency at which output is changed from non-inverting state to inverting state and vice versa depend upon the switching frequency of the operating transistors. This sort of output and the corresponding load current is demonstrated in Figure 7b,d, respectively. On the other hand, the input current is almost continuous, as shown in Figure 7c, because it is conducted through two transistors and two diodes in all operating modes. This characteristic of the input current depicts the improved power quality that may be evaluated in terms of power factor, harmonic factor, and total demand factor. The determination of the power quality concern of the input current is carried out in Simulink based environment by taking its FFT as shown in Figure 8. It can be observed that low distortion of the input current results in a high value of its fundamental component compared to the harmonics or unwanted components. The power factor can be approximated directly from the harmonic factor as the distortion level of the input voltage is negligible. In the proposed circuit topology, a 1 \(\upmu\)F capacitor is connected across the input source to tackle the unwanted distortion in the input voltage that may be caused by the utility power quality problem or some switching harmonics that may be generated due to high switching \begin{table}
\begin{tabular}{c c} \hline \hline
**Parameter** & **Value** \\ \hline Input peak voltage & 150 V \\ \hline Input frequency & 50 Hz \\ \hline Internal resistance of transistor & 80 m\(\Omega\) \\ \hline Internal resistance of diode & 6 m\(\Omega\) \\ \hline Forward voltage of diode & 1 V \\ \hline Series inductance & 500 \(\upmu\)H \\ \hline Load impedance & 80 \(\Omega\) \\ \hline Switching frequency & 25 kHz \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Parameters employed for simulation results. operation of the switching transistors. The following mathematical form explores the effect on the power factor with respect to the variation in the harmonic factor of the input current. \[p.f=\sqrt{\frac{1}{1+HF_{current}^{2}}}=0.99\,\mathrm{lag} \tag{22}\]  
It can be observed that the true power factor is approximately unity as there is a very low harmonic factor (0.82%) of the input current. Figure 8: Validation for power quality of the input current.