Power source sizing of fuel cell hybrid vehicles considering vehicle performance and cost

Power source sizing is an important step when designing hybrid vehicles, which directly influences the fuel economy and total cost of hybrid vehicles. This research presents a power source sizing methodology for fuel cell hybrid vehicles (FCHVs) considering the vehicle performance and cost. Acceleration time and maximum speed of the vehicle are introduced as the constraints on choosing effective power source size combinations. The powertrain mass difference resulted from different power source sizes is taken into account when dealing with the constraints, and consequently different constraint line is applied to different power source size combination. Different sizes of batteries and fuel cell systems (FCSs) in the effective region are modeled in order to select the best power source size combination according to sizing objectives (criterion). The sizing objective in this research is to minimize the fuel consumption or to minimize the total cost (FCS cost plus battery cost plus consumed hydrogen cost). A Pontryagin's Minimum Principle (PMP)-based power management strategy is adopted when comparing the fuel consumption, and some reference values are introduced to the cost comparison. Power source sizing results reveal that the best power source size combination is different for the two sizing objectives.