# A Novel Secondary Side Series LCD Forward Converter with High Efficiency and Magnetic Reset
## 5 Simulation and Experimental Analysis
### Experimental Analysis  
In order to verify the performances and simulations further, we considered the following factors, such as the circuit power, efficiency, and output voltage ripple. The experimental prototype was developed, as shown in Figure 8. The key parameters were same as the simulated parameters. According to the working principle of the proposed converter and the existing equipment and safety practices in the laboratory, the selected parameters of the model are given in Table 2.  
In order to verify the correctness of the optimal operating mode of the converter and its parameter design method, when the input voltage was DC300V, the waveforms of \(V_{gs}\), \(V_{\mathrm{ds}}\), \(i_{L1}\), and \(i_{L2}\) with output currents of 2 A, 5 A, and 10 A, respectively, were tested using the experimental prototype, as shown in Figure 9.  
Figure 7: Simulated waveforms of the main components of the converter with different output loads. (**a**) Waveforms of \(V_{gs}\), \(V_{\mathrm{ds}}\), \(i_{L1}\), and \(i_{L2}\) when \(I_{o}=2\) A; (**b**) Waveforms of \(V_{gs}\), \(V_{\mathrm{ds}}\), \(i_{L1}\), and \(i_{L2}\) when \(I_{o}=5\) A; (**c**) Waveforms of \(V_{gs}\), \(V_{\mathrm{ds}}\), \(i_{L1}\), and \(i_{L2}\) when \(I_{o}=10\) A.  
Figure 8: Experimental prototype. \begin{table}
\begin{tabular}{c c} \hline
**Components** & **Part Number** \\ \hline Power switch \(S\) & 80R280P7 \\ Diodes \(D_{1}\)–\(D_{4}\) & MM60F060 PC \\ Transformer core \(T\) & EE/42/21/15 \\ Control chip & UC3845 \\ \hline
**RIGOL** STOP & 5.00 us 2555s/us 1258 pts & MEASUUR \\ \hline
**Figure 9**: _Cont._As shown in Figure 9, the voltage waveform of \(V_{\rm ds}\) first increased in a curve and then decreased in a curve during the switch-off period, indicating that \(L_{\rm m}\) operated in the DCM. However, the inductor currents \(i_{L1}\) and \(i_{L2}\) were greater than zero throughout the entire switching period, indicating that the inductors \(L_{1}\) and \(L_{2}\) both operated in the CCM, which proves that the proposed converter operated in the optimal operating mode. At the same time, it can be seen in Figure 9 that when the output current of the converter was significant, the voltage stress on the power switch was equal to the input voltage at the switch-on moment. When the output current of the converter was minimal, the voltage stress of the switch was obviously lower than the input voltage at the switch-on moment. The above analysis shows that the proposed converter achieved a low-voltage turn-on of the switch. Therefore, the correctness of the above mentioned optimal working mode and its parameter design method was verified. Meanwhile, by comparing the experimental waveform with the simulated waveform, it can be seen that they were generally consistent. According to the performance index requirements of the prototype, under an input voltage of 220 VAC, the output voltage was tested using different load conditions. Table 3 shows the experimental results of the proposed converter. Table 3 presents the maximum variation when the output voltage was 0.23 V. Therefore, the load adjustment rate of the experimental prototype was obtained as the following. \[U=\frac{\Delta V_{\mathrm{o}}}{V_{\mathrm{o}}}=\frac{48.14-47.91}{48}=0.47\% \tag{38}\]  
From Equation (38), it can be seen that the load adjustment rate of the developed experimental prototype met the design requirements. The output ripple was an important technical index of the converter. According to the design index of the prototype, the output ripple voltage should be less than 1%\(V_{\mathrm{o}}\); that is, the output ripple voltage should be less than 480 mV. The waveform of the output ripple voltage was tested using full load conditions, as shown in Figure 9.  
As shown in Figure 10, the peak-to-peak output voltage ripple of the proposed converter was 200 mV, which was less than 1%\(V_{\mathrm{o}}\). Therefore, the prototype designed in this paper met the index requirements of the converter. Figure 10: Waveform of the output ripple voltage.