# Ferrites and Nanocrystalline Alloys Applied to DC-DC Converters for Renewable Energies
## 4 Simulation  
The equivalent circuit of the MFT is implemented in Simulink-MATLAB. Figure 6 shows the Full-Bridge converter and the equivalent circuit of the MFT. Both MFTs are tested with square waves.  
The parameters, input voltages, operating frequency, and load for the simulations are presented in Table 7. In the equivalent circuit, \(R_{1}\) and \(R_{2}\) are the resistances of the primary and secondary winding, respectively, \(L_{m}\) is the magnetization inductance, \(R_{m}\) is the magnetization branch resistance, and \(L_{d1}\) and \(L_{d2}\) are the primary and secondary dispersion inductances.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{2}{c}{**MFT**} & \multicolumn{2}{c}{**MFT with Ferrite Core**} & \multicolumn{2}{c}{**MFT with Nanocrystallyne Core**} \\ \hline \multicolumn{2}{c}{\(L_{d}\)} & \multicolumn{2}{c}{2.06 \(\mu\)H} & \multicolumn{2}{c}{\(1.01\)\(\mu\)H} \\ \hline \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \multicolumn{2}{c}{} & \multicolumn{1}{c}{} & \\ \hline \end{tabular}
\end{table}
Table 6: Dispersion inductance calculated in both MFTs.  
Figure 5: The 0.6–20 kHz \(L_{d}\) curves: (a) ferrite, (b) nanocrystalline alloys.  
Figure 7a,b shows the input and output voltages and currents of the nanocrystalline and ferrite MFTs, respectively. Table 8 shows the values of each input/output signal in both MFTs as well as the efficiency obtained in each case.  
Figure 7 and Table 8 evidence that the nanocrystalline MFT has better performance and efficiency than the ferrite MFT.  
The high efficiency obtained from both MFTs (>98%) opens the possibility of using any of both materials in high-performance applications, but comparing parameters of high impacts, such as the power density and construction cost, makes the difference, as shown in Section 5.  
\begin{table}
\begin{tabular}{c c c} \hline
**MFT** & **MFT with Ferrite Core** & **MFT with Nanocrystallyne Core** \\ \hline \(V_{in}\) & 120 V & 120 V \\ \(f\) & 20 kHz & 20 kHz \\ \(Load\) & 60 \(\Omega\) & 60 \(\Omega\) \\ \(L_{d1}\) & 2.06 \(\mu\)H & 1.01 \(\mu\)H \\ \(L_{d2}\) & 9.09 \(\mu\)H & 4.06 \(\mu\)H \\ \(R_{1}\) & 0.0300 \(\Omega\) & 0.0114 \(\Omega\) \\ \(R_{2}\) & 0.1222 \(\Omega\) & 0.0465 \(\Omega\) \\ \(L_{m}\) & 10.2 mH & 28.7 mH \\ \(R_{m}\) & 6288 \(\Omega\) & 10,909 \(\Omega\) \\ \hline \end{tabular}
\end{table}
Table 7: Parameters of the simulation model.  
\begin{table}
\begin{tabular}{c c c} \hline
**MFT** & **MFT with Ferrite Core** & **MFT with Nanocrystallyne Core** \\ \hline \(V_{in}\) & 120 V & 120 V \\ \(V_{o}\) & 235.4 V & 237.8 V \\ \(l_{in}\) & 7.852 A & 7.936 A \\ \(l_{o}\) & 3.924 A & 3.963 A \\ Efficiency & 98.03\% & 98.96\% \\ \hline \end{tabular}
\end{table}
Table 8: Input and output voltages and currents for MFTs.  
Figure 6: Full-Bridge converter and equivalent MFT circuit.