# Modelica-Based Energy Management of PEMFC Hybrid Power System of Vehicle
## 5 Conclusions  
This study presents a comprehensive investigation into a PEMFC-based hybrid power system designed for a 100 kW vehicle, focusing on energy management strategies and temperature control. By integrating the state machine (SM) and model predictive control (MPC) methods, a novel SM-MPC energy management strategy (EMS) is proposed, achieving notable improvements in system performance compared to conventional methods.  
The simulation results demonstrate the effectiveness of the SM-MPC method in optimizing power allocation between the PEMFC and lithium-ion battery. In both NEDC and HWFET driving cycles, the SM-MPC method maintains the battery SOC near the reference value and achieves lower hydrogen consumption compared to the SM and MPC methods. For instance, in the NEDC cycle, the SM-MPC method reduces hydrogen consumption by 7.11 g compared to the MPC method and by 18.22 g compared to the SM method. This underscores the potential of the proposed method in enhancing the energy efficiency of hybrid power systems while ensuring the stability of system operations. Additionally, this study incorporates a PID controller for stack temperature management. The results reveal that the controller effectively regulates the stack temperature within \(\pm\)5.8 \({}^{\circ}\)C of the target value during dynamic driving conditions.  
In conclusion, the integration of SM and MPC methods provides a promising solution for addressing the nonlinear and dynamic challenges of hybrid power systems. The proposed SM-MPC EMS not only improves energy utilization but also enhances the operational stability of the PEMFC and lithium-ion battery. However, this study simplified the mathematical models of PEMFC and lithium batteries, and in the future, the nonlinear characteristics of parameters in the models can be considered to improve their accuracy. Furthermore, future work will also focus on refining the control algorithms, exploring real-time adaptability under complex driving conditions, and incorporating additional components to achieve more precise system modeling and control.  
Figure 13: Rotation speed and power consumption variations of the fuel cell stack under the PID controller.  
**Author Contributions:** Conceptualization, K.Z. and X.S.; methodology, [PERSON]; software, [PERSON]; validation, [PERSON]; formal analysis, X.S. and J.D.; investigation, [PERSON]; resources, [PERSON]; data curation, [PERSON]; writing--original draft preparation, [PERSON]; writing--review and editing, [PERSON]; visualization, [PERSON]; supervision, K.Z. and J.D.; project administration, K.Z.; funding acquisition, [PERSON] All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research was funded by the technology project about the development and application of hydrogen-lithium hybrid zero-carbon power generation system equipment for long-term emergency supply, grant number JC2024115.  
**Data Availability Statement:** Data will be made available on request.  
**Acknowledgments:** Sincere thanks to Changzhou Changgong Electric Power Design Institute Co., Ltd. for their financial support of the scientific research project.  
**Conflicts of Interest:** Author [PERSON], [PERSON], [PERSON] and [PERSON] were employed by the company Changzhou Changgong Electric Power Design Institute Co., Ltd. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.