A comparative study of fuel-cell--battery, fuel-cell--ultracapacitor, and fuel-cell--battery--ultracapacitor vehicles

Although many researchers have investigated the use of different powertrain topologies, component sizes, and control strategies in fuel-cell vehicles, a detailed parametric study of the vehicle types must be conducted before a fair comparison of fuel-cell vehicle types can be performed. This paper compares the near-optimal configurations for three topologies of vehicles: fuel-cell-battery, fuel-cell-ultracapacitor, and fuel-cell-batteryultracapacitor. The objective function includes performance, fuel economy, and powertrain cost. The vehicle models, including detailed dc/dc converter models, are programmed in MATLAB/Simulink for the customized parametric study. A controller variable for each vehicle type is varied in the optimization. Index Terms--Batteries, dc-dc power conversion, fuel cells, optimization methods, vehicles.