## 4 Simulation Results
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Parameter** & **Value** & **Parameter** & **Value** \\ \hline SOCBAT\_min & 0.6 & \(\eta_{\rm IP}\) & 0.007 \\ SOCBAT\_max & 0.9 & \(\eta_{\rm II}\) & 0.05 \\ KP\({}_{1}\) & 0.043 & \(\delta\) & 0.01 \\ KI\({}_{1}\) & 0.65 & \(\gamma\) & 0.3 \\ KP\({}_{2}\) & 0.01 & \(\kappa\) & 1.65 \\ KI\({}_{2}\) & 0.5 & \(\varepsilon\) & 0.9 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: EMS strategy parameters. Power distributions of the PEMFC, BAT, and SC under three comparative EMSs are presented in Figure 10. As expressed in Figure 10a, the PEMFC powers of the RB-EMS and ECMS have a high power level that can diminish the aging and performance of the PEMFC system. Meanwhile, the proposed F-EMS provides a better performance indicator with a suitable change rate of PEMFC power and smaller power fluctuation, which can improve the fuel economy and durability of the PEMFC system. The power capability of the BAT under three EMSs is depicted in Figure 10b. It can be seen that the BAT power of the proposed strategy is higher than those of both the RB-EMS and ECMS during the  
Figure 11: The comparison of the DC bus voltage. Figure 12: The SOC comparison. (**a**) BAT; (**b**) SC. period of acceleration. This is because the output power of the PEMFC when using the proposed F-EMS is lower than the other methods, thus the BAT power must be more discharged to compensate for the lacking power from the fuel cell source to match the load power demand. However, in the regenerative mode, the proposed F-EMS can provide a smooth power response to charge the redundant power from the DC bus to the BAT. The comparative result of the SC power distribution is illustrated in Figure 10c. Due to the fast power response, the SC is employed to supplement the slow power response of the PEMFC and BAT to power the load. As a result, the proposed algorithm regulates the SC power in a suitable range that can accommodate abrupt power of load and reduce power fluctuation of the PEMFC and BAT despite the rapid load change. The comparison of DC bus voltage corresponding to the load power demand is shown in Figure 11. By using the proposed F-EMS, the DC bus voltage is steadily maintained at around 750 V with a smaller fluctuation than using the RB-EMS and ECMS. In the change interval of the load, the DC bus peak voltage is in the range of \((746\to 753)\) V, approximated by a 1% voltage ripple, by using the proposed F-EMS. This result is better than the ones under the RB-EMS with the range of \((743\to 755)\) V and ECMS with the range of \((741\to 757)\) V.  
Simulation results of both BAT and SC SOC are shown in Figure 12, which describes the charge and discharge status at each timeline when the load changes. In Figure 12a, the suggested F-EMS can maintain the increasing range of BAT SOC lower than the RB-EMS and ECMS. For the SC, Figure 12b shows that the SOC level varies around 85%. Herein, the proposed approach achieves a SOC varying range within \((84.65\to 85.2)\) % that is lower  
Figure 13: The comparison of fuel consumption and efficiency of PEMFC stack. **(a)** Hydrogen consumption; **(b)** Stack efficiency. than the ECMS with the range of \((84.35\to 85.3)\,\%\), while RB-EMS has a large fluctuation in \((84.3\to 85.5)\,\%\). The hydrogen consumption and the PEMFC stack efficiency of three EMSs are described in Figure 13. As a result, the proposed F-EMS consumes lower hydrogen fuel than the RB-EMS and ECMS as presented in Figure 13a. In the case of the proposed strategy, the average amount of hydrogen consumption is 0.275 kg during the time of the driving cycle, whereas the total fuel consumption of the RB-EMS and ECMS reaches 0.35 kg in the same working conditions. It proves that the proposed approach gives better fuel economy with the hydrogen consuming less than 21.4% in comparison with other approaches. Furthermore, with the same driving cycle, the PEMFC stack efficiency of three EMSs is evaluated as well.