## 4 Discussion
Furthermore, these results underline once again the importance of the proposed model for a preliminary evaluation of the impact of electronic devices in the converter performances since the differences in the final results can be anything but negligible. As anticipated in the previous section, the drain series MOSFET inductance can have a value similar to _Lf_. In the datasheet of MOSFETs considered in this work, the values of parasitic inductance are not reported. In addition, according to [42,43], a value of about 20 nH can be assumed. This inductance can be included in the proposed converter model by adding an inductance \(L_{\text{rms}}\) in series with \(L_{f}\). \(L_{\text{rms}}\) can be evaluated as the double of the drain series MOSFET inductance, since, with a full-bridge inverter, two MOSFETs are in conduction in each half-period. So, considering an \(L_{\text{rms}}\) inductance of 40 nH, a comparison in terms of output power with Simulink and our proposed model has been performed. Results are provided in Figure 12 for the two kinds of MOSFET as functions of the load resistance. As can be seen, this inductance has a non-negligible effect in the converter performances (output power is significantly lower compared with Figure 11) because, for this particular converter topology, the performances are strictly influenced by the value of the filter inductance (that, in this case, is the series between \(L_{\text{rms}}\) and \(L_{f}\)). Furthermore, the proposed approach, averaged with the ideal model, can still predict results very similar to Simulink. Finally, a discussion on how to estimate MOSFET losses with the proposed model can be conducted. In particular, conduction losses can be calculated putting in series with the \(L_{f}\) inductance a resistance equal to the double of the drain-source MOSFET resistance (\(R_{\text{DS}}\)): this is because two MOSFETs are in conduction, in a full-bridge inverter, for each half-period. Switching losses can be evaluated as the double (for the same reason of conduction losses) of the average power, in one period, between the current in the \(L_{f}\) inductance and the  
Figure 12: Output power values achievable in the LCC-s converter using an ideal model (model in Section 2 with square input voltage), Simulink (reference model) and a proposed model (model in Section 2 with trapezoidal input voltage) for different load resistance values (\(\text{V}_{\text{dc}}\) = 30 V) when parasitic inductances of MOSFETs (40 nH) are considered. Also, the average between ideal and proposed models is shown. (**a**) IPPB009N03L (Infineon) MOSFET. (**b**) PSMN1R440 YLD (Nexperia) MOSFET. linear strokes of the trapezoidal input voltage. In parallel, in Simulink, the average power in one period between voltage and current across the MOSFET represents the total loss in the device (switching and conduction); the total losses in the inverter can be obtained multiplying by four the losses on the single MOSFET. The two contributions can be split by evaluating conduction losses as the average power on the RDS MOSFET resistance, so the switching losses will be the difference between total losses and conduction losses. In addition, we performed some tests in Simulink, and then we saw that conduction losses are extremely lower than the switching one (as also expected in the literature); indeed, it has to be considered that the \(R_{DS}\) resistance is very low: 0.95 m\(\Omega\) for IPPB009N03L MOSFET and 1.6 m\(\Omega\) for PSMN1R440 YLD MOSFET. So, the attention can be focused just on switching losses. Considering the IPPB009N03L MOSFET, the comparison of switching losses calculated using Simulink and the proposed model as function of input voltage and load resistance is shown in Figure 13.  
As can be seen, the two approaches provide similar results. This kind of analysis can be exploited to evaluate not only the performances of MOSFETs, but also the resulting global efficiency of the converter.