## 7 Discussion  
Now we are going to discuss the results of the previous section and of the whole paper in general. As we are going to demonstrate next, the quality of the developed model (Figure 1) is excellent for the three DC/DC power converters' basic topologies. First of all it is important to discuss the way to obtain in the literature [24; 36; 37; 38; 39] the conventional expressions (practically ideal, \(h=1\), except for taking into account the internal inductor resistance \(r\)) for \(A_{Vr}\), \(R_{i}\) and \(h\). Authors arrive at these expressions from approximations from the beginning, specifically considering that the current through \(r\) is constant and equal to a mean value. In the developed model, you get to the same expressions (Sections 3.5, 4.5 and 5.5), but without previous approximations and by the resolving of exact equations. Analyzing Figure 16 it is easy to note how the developed model fits the voltage gain (\(A_{Vr}\)) of the actual boost converter. In fact, as you can see in Table 1, the (NMAE%) is negligible, only 0.45%. Figure 16 shows up the great influence of its non-idealities on an actual boost converter operation. Ideally, a boost converter presents no upper limit in the gain (55), so it can take anyone above 1. However, in the actual case, as it is well known, and the developed model is able to show, the gain is drastically modified. Although the conventional model error is also small (2.93%), it is 6.5 times greater than the developed model. Continuing the boost converter and regarding its input resistance, Figure 17 shows again the quality of the model, NMAE% is very small, only 0,66% (2.19% in the conventional model). Finally, regarding efficiency, Figure 18 shows that NMAE is again negligible, 0.3%. Here is where the difference among the quality of the developed model and the conventional one is more notable, specifically the error of the latter is 9 times greater (2.69%). Knowing the actual efficiency of a converter is very important; in fact, in most facilities, DC/DC converters are a post-generator mandatory stage. The foregoing means that the overall efficiency of the system up to the regulated-voltage output is the product of the generator and converter efficiency. Thus, it is of great interest to know the actual DC/DC converter losses and, from them, its true efficiency. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Model** & **Converter** & \(A_{W}\) & \(R_{i}\) & \(h\) \\ \hline \multirow{3}{*}{Developed} & Boost & 0.45\% & 0.66\% & 0.30\% \\  & Buck & 0.73\% & 1.61\% & 0.31\% \\  & Buck-boost & 1.4\% & 1.98\% & 0.84\% \\ \hline \multirow{3}{*}{Conventional} & Boost & 2.93\% & 2.19\% & 2.69\% \\  & Buck & 7.10\% & 5.39\% & 8.09\% \\ \cline{1-1}  & Buck-boost & 7.57\% & 5.87\% & 8.65\% \\ \hline \hline \end{tabular}
\end{table} 
Table 1: NMAE% for the developed and conventional models regarding the actual converters. \begin{table}
\begin{tabular}{l c c c} \hline \hline
**Parameter** & **Boost** & **Buck** & **Buck-boost** \\ \hline \(R_{X}\) & \(\frac{1-b}{r+R_{5}}+\frac{r^{2}+0}{r+R_{5}}\) & \(\frac{r+R_{5}}{r+R_{5}}\) & \(\frac{r+R_{5}}{r+R_{5}}\) \\ \(V_{X}\) & \(V_{7}\) & \(\left[\frac{bR_{5}}{r+R_{5}}\right]\) & \(\frac{-V_{7}}{r+R_{5}}\) \\ \(A_{Vr}\) & \(1 Now, regarding the buck converter, Figures 19-21 show the behavior of \(A_{Vr}\), \(R_{i}\) and \(\eta\). For the developed model, NMAE% is again negligible: 0.73%, 1.61% and 0.31% respectively. However, for the conventional model, NMAE% is 7.10%, 5.39% and 8.09% respectively. Again the differences are notable, and especially regarding efficiency, where the error is much worse than in the buck converter, specifically 26 times greater. Finally, regarding buck-boost converter, Figures 22-24 show the behavior of \(A_{Vr}\), \(R_{i}\) and \(\eta\). For the developed model, NMAE% is once again negligible: 1.4%, 1.98% and 0.84% respectively. In the case of the conventional model, NMAE% is: 7.57%, 5.87% and 8.65% respectively.