## 3 Implementation of the Proposed Three-Phase Modular Rectifier  
To validate the proposed three-phase rectifier, a simulation study was carried out, using the PSIM software version 12. The construction of an experimental prototype is under development. The most important parameters used in the simulation are shown in Table 1. It is important to note that the proposed rectifier was dimensioned and analyzed for a power of 20 kW, and therefore the load has a value of 29 \(\Omega\). However, to analyze the behavior of the PF and the THD of the rectifier in changes in load resistance, it will also be evaluated for 1%, 20%, 40%, 60%, and 80% of the 20 kW power. This corresponds to loads of 289 (1%), 144 (20%), 72 (40%), 48 (60%), 36 (80%), and 29 \(\Omega\) (100%). The proposed circuit is divided (assembled) in the PSIM by three circuits, the power circuit, the interface circuit, and the control circuit, as can be analyzed in Appendix A. Power circuit: this is where the energy is processed between the source and the load. Among the various elements constituted, the boost converter inductor, the DMCF, and the output capacitor are most important. The boost inductor \(L_{b}\) was calculated according to (17), whereas the output capacitor \(C_{\text{o}}\) is calculated by (18), similarly to the proposed in [23]:  
\[L_{b}=\frac{3\cdot V_{p}^{2}\cdot\left(2V_{o}-3V_{p}\right)}{f_{\text{s}}\cdot \Delta L_{\text{L}\%}\cdot 4\cdot P_{o}\cdot V_{o}} \tag{17}\]  
\[C_{\text{o}}=\frac{2\cdot P_{o}\cdot t_{\text{hold}}}{V_{o}^{2}-\left(0.9\cdot V _{0}\right)^{2}} \tag{18}\]  
where \(f_{\text{s}}\) is the switching frequency, \(\Delta L_{\text{L}\%}\) is the current variation in the boost inductor in percentage, and \(t_{\text{hold}}\) is the hold-up time (the time that the system keeps the energy in the output capacitor). The value of the inductances in DMCF, illustrated in Table 1, is chosen for a best possible operation of the circuit. Control circuit: The control strategy for the proposed three-phase rectifier is based on [23; 24]. The control technique is performed using mean values in continuous driving mode. To this end, the IC UC3854B was used, since it internally incorporates all the circuits necessary for the implementation of the control and was designed for boost converters with single-phase PFC. For better understanding, a basic diagram of the UC3854B control process is illustrated in Figure 7, in just one rectifier module. Basically, control starts at the multiplier/divider, with the reference current as the output and parameters A, B, and C as input. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Components** & **Description** & **Values** \\ \hline \(V_{lin-rms}\) & RMS line voltage & 380 V \\ F & Network frequency & 50 Hz \\ \(V_{o}\) & Output voltage & 760 V \\ \(P_{o}\) & Output power & 20 kW \\ \(L_{b}\) & Inductance of boost inductor & 1 mH \\ \(L_{1}\), \(L_{2}\) & Self inductance of DMCF & 1 mH \\ M & Mutual inductance of DMCF & 0.99 mH \\ \(C_{\text{o}}\) & Output capacitor & 3300 uF \\ \(R_{o}\) & Load & 29 \(\Omega\) \\ \(f_{\text{s}}\) & Switching frequency & 100 kHz \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Parameters used in the simulation. Figure 7: Basic diagram of UC3854B control. Parameter A is the synchronism signal, that is, a rectified sinusoid signal from the input voltage, and defines the shape, frequency, and phase of that reference signal transformed into a current signal. Parameter B is the voltage regulator error signal, which provides control of the output voltage by varying the error signal that adjusts the amplitude of the reference current according to the load variation. It corresponds to the necessary amplitudes of the sinusoidal phase current that the rectifier should take from the input. The parameter C is the feed-forward control signal that corresponds to the rms value of the input voltage. That signal is obtained by approximated value obtained by filtering.