Dynamic modeling and operation strategy of an NG-fueled SOFC-WGS-TSA-PEMFC hybrid energy conversion system for fuel cell vehicle by using MATLAB/SIMULINK

Proton exchange membrane fuel cells (PEMFCs) are promising energy conversion devices for electrical vehicles. A reformer is needed when natural gas is used for fuel cell vehicles. The reformer can be replaced by a solid oxide fuel cell (SOFC) which can reform natural gas and produce power simultaneously, which in turn can enhance the energy efficiency. In this paper, an SOFC/PEMFC hybrid system is proposed and numerically studied to improve energy efficiency and dynamic response. A water gas shift and thermal swing adsorption subsystem is integrated into the hybrid system to ensure pure H₂ for PEMFC. It is found that slow transient response of the SOFC dominates short-term dynamic behaviors, while fast response of the PEMFC governs mid-term dynamic behaviors. The results also show that the integrating thermal swing adsorption reactor and H₂ buffer as a single H₂ fuel source for PEMFC contributes to enhanced dynamic behaviors. The hybrid system with SOFC to PEMFC power distribution of 6:4 could stabilize output power within 20 s with a high energy efficiency of over 60% when used to power a 300 kW fuel cell vehicle. The proposed system is promising for electrical vehicle applications with enhanced energy efficiency and dynamic response.