A proton exchange membrane fuel cells (PEMFC) have garnered significant attention from automobile manufacturers due to their advantages of high energy density, zero carbon emissions, and low operating temperatures. When applied to high-power vehicles, fuel cell hybrid systems must meet driving demands while achieving high fuel economy. However, the limited availability of fuel cell vehicles poses significant challenges in fully understanding the performance behavior of the high-power vehicles. To bridge this gap, this study explores the design of the hybrid fuel cell system to understand the feasibility of power capacity in a fuel cell light-duty vehicle. In particular, a fuel cell stack of commercial vehicles is presumed as one power module for the vehicle. Power demand of the vehicle is then matched with either a single module or a dual module of fuel cell power module so that the fuel economy results can be investigated under different driving modes.
A backward simulation model of the vehicle is developed using the Matlab/Simulink, incorporating a comprehensive powertrain consisting of a fuel cell system, a lithium-ion battery pack, power conversion systems, an electric motor, and controllers. Required powers are determined based on vehicle dynamics to meet maximum speed, acceleration performance, and gradeability of a passenger vehicle. Key parameters such as fuel cell system efficiency, energy flow, and fuel economy are evaluated over the city and highway driving cycles. The obtained simulation results showed that the single-stack configuration provided a 11% improvement in fuel economy in highway driving schedule than that in city traffic conditions. The dual-stack configuration demonstrated a 25% enhancement in fuel economy over the highway driving cycle compared to urban driving. When combining the results from both driving schedules, the single-stack configuration achieved 12% higher combined fuel economy than the dual-stack system.