## 4 Discussion
Figure 11 presents the speed transition from resting to low (40 km/h), then low (40 km/h) to high (80 km/h), and finally, from high (80 km/h) to low-speed mode (40 km/h), respectively. The first transition response time remained the same, while the second was 1.6 s and the third was 1.4 s. The overshoot of the first transition was 5%, and the overshoot of the second transition was 15%, while the undershoot of the third transition was 5%. The waveform in Figure 12 represents the IM operation for the low (40 km/h) and high (80 km/h) speed modes. In Figure 12a, as the measured speed rises, the torque value falls. Figure 12b summarizes the variation in torque and phase current with a measured tracking speed mode of 40 km/h. The analysis suggests that as the desired speed is achieved, both  
Figure 11: IM application in EV model for speed modes (0–40, 40–80, 80–40 km/h) and load torque at 100 Nm, to compare its effects on torque, current, and voltage. Figure 10: IM application in EV model for speed modes (0–40, 40–60, and 60–80 km/h) and load torque at 100 Nm, to compare its effects on torque, current, and voltage. the torque and phase current reach the minimum value accordingly. Figure 12c portrays the variation of the three-phase current values at speed modes of 60 and 80 km/h. When the speed mode at 60 km/h is applied, the current reaches the maximum value; as the reference speed is achieved, the three-phase current value drops. When the next speed mode at 80 km/h is applied, the first current value rises; as the model tries to reach the reference speed of 80 km/h, the three-phase current value reaches its minimum value. Figure 13 presents a zoomed-in view of the variations in the three-phase voltage supply for the 60-80 km/h speed mode. In the next step, the swing equation is implemented to calculate the accelerated power. The rotor angle, measured at a 2 s threshold for a 40 km/h speed command, is approximately 112\({}^{\circ}\); this matches the results of the FFT analysis performed on the model. The calculated accelerated power is approximately 4.7 kW for both cases. This verifies the model validation for efficiency analysis. Figure 5:0 Input and output parameters against the given speed mode for IM 50 HP. (**a**) Speed and torque at a speed mode of 80 km/h. (**b**) Speed, torque, and current at a speed mode of 40 km/h. (**c**) Variations in three-phase current and speed at the speed modes of 60 and 80 km/h. Figure 5:1 Zoom-in of the 3-phase current in Figure 12c. In Table 2, the error is calculated between measured and estimated efficiency (for the proposed algorithm, IEEE standard, and IEC standard) [23]. In the first stage, the speed of the IM of the experimental setup is converted to km/h using Equation (25). For 50 hp IM, 1770.0 rpm is converted into 266 km/h. Thus, after conversion, the required test speed of 60 km/h is calculated as 398 rpm. Figure 5:2  
The mechanical output power is calculated by using the formula in Equation (26). Figure 5:3  
where \"\(\omega_{\text{r}}\)\" denotes the rotor speed and T is the developed torque by the IM. The input power of IM is computed with the output power for efficiency calculations. Input power is calculated as 54,863 watts by taking the RMS current and phase voltage value. The mechanical form of the output power at 60 km/h speed is calculated as 42,970 watts. Therefore, the efficiency of the running model is 78.3%. The error percentage for the no-load condition is less than unity (0.5305%). A drop in the efficiency of IM from 94.37% to 78.3% can be seen in Table 2[24]. A decrease in IM efficiency from unloaded to loaded operation is observed, due to the loading effect applied to match the required speed mode. A drop in speed in the given proposed model indicates that the loaded motor performance is observed while considering all experimental factors. Moreover, the efficiency of the IM improves as the reference speed reaches the maximum rated speed.