## 6 Simulation Results  
This research objective is to design a closed-loop electro-thermal model of an EV inverter and validate it through real data. Therefore, the complete MATLAB simulation of an inverter with IM control has been developed. According to Figure 24, results are obtained from the simulation model using the NEDC speed profile in Figure 17. In the simulation, nearly three cases are produced by varying the load torque of a motor. The load torque is changed from 10 Nm to 105 Nm from 268 s to 278 s at an NEDC speed of 2106 RPM, as shown in the zoom plots of Figure 24. Similarly, the other two cases produced the torque of 24.6 Nm (from 850 s to 890 s) and 14 Nm (from 1075 s to 1095 s) at NEDC speeds of 4600 RPM and 6571 RPM, respectively, as shown in zoom plots of Figure 24. \begin{table}
\begin{tabular}{c c c c c c c} \hline \multirow{2}{*}{**Cases**} & \multirow{2}{*}{**Torque (Nm)**} & \multirow{2}{*}{**Speed (RPM)**} & \multirow{2}{*}{\begin{tabular}{c} **Ambient** \\ **Temperature** \\ \end{tabular} } & \multicolumn{2}{c}{\
\begin{tabular}{c} **Efficiency** \\ **(\%)** \\ \end{tabular} } & \multicolumn{2}{c}{
\begin{tabular}{c} **Case Temperature** \\ **(\({}^{\circ}\)C)** \\ \end{tabular} } \\ \cline{4-7}  & & & (\({}^{\circ}\)C) & **Actual** & **Simu.** & **Actual** & **Simu.** \\ \hline
1 & 105 & 2760 & 25 & 96.3 & 96.5 & - & - \\
2 & 24.6 & 5382 & 25 & 97.6 & 97.5 & 51 & 51.5 \\
3 & 14 & 7700 & 25 & 98.0 & 97.8 & 44 & 45.2 \\ \hline \end{tabular}
\end{table} 
Table 4: Actual vs. simulation validation. Figure 23: Thermal model PLECS validation of (**a**) MOSFET, (**b**) diode. The ambient temperature is considered at 25 \({}^{\circ}\)C. The implemented controllers track the speed and torque reference command generated by the speed controller, as depicted in Figure 24. The efficiency (%), case temperature (\({}^{\circ}\)C), and power flow (kW) of three cases of the inverter are investigated using a simulation model, as shown in Figure 25. The zoom plots of Figure 25 depict the efficiency and case temperature are similar as declared in the experimental results of Table 4. The simulation results of Figure 25 reflect the efficiency and temperature of case-1, case-2, and case-3 at time intervals of 268-278 s, 850-890 s, and 1075-1095 s, respectively. The simulated efficiencies and temperatures for case 1 are 96.5% and 87 \({}^{\circ}\)C, for case 2 are 97.5% and 51.5 \({}^{\circ}\)C, and for case 3 are 97.8% and 45.2 \({}^{\circ}\)C. The simulation model estimates the junction temperature of MOSFET and diode by using a thermal model as presented in Figure 16. These junction temperatures are used for power loss calculation for the next iteration. The power loss (W) in power electronic modules of the inverter and junction temperature (\({}^{\circ}\)C) of the MOSFET and the diode of each leg for the entire NEDC speed have been depicted in Figure 26. Three-phase inverter currents (A), voltage (V), conduction power loss (W), and instantaneous switching power loss (W) of an upper and a lower MOSFET as well as body diodes are depicted in Figures 27 and 28. Thus, this accurate simulation model of Si-based MOSFET can be applied to design and optimize the new WBG technology-based EV inverter. The simulation model can be parameterized easily by varying the devices, i.e., GaN, SiC, and Si materials, switching frequency, input/output voltage, power rating, motor parameters, control gains, and operating range of temperature. The analysis can be performed to enhance inverter efficiency, power quality, and control system performance. Due to the limitation of Si-based MOSFET devices, it is not possible to increase the switching frequency beyond 20 kHz. However, there is no limit to this simulation model for investigating performance and power quality by parameterizing according to the WBG-based power electronic devices. WBG can operate at high switching frequencies.