A Comparative Study of Fuel Cell Electric Vehicles Hybridization with Battery or Supercapacitor

This paper deals with the conception and the achievement of a hybrid power source using a fuel cell combined with a battery or a supercapacitor. In which, the fuel cell supplies the main power to the drive system; while the battery or the supercapacitor is used as an auxiliary power source. This gives the benefit that the regenerative energy is stored in battery or supercapacitor during the deceleration and it is transferred back to the drive system during the acceleration when compared to electric vehicles solely powered by a fuel cell. Different energy storage devices, such as fuel cell, battery, and supercapacitor are compared., and then several structures of fuel cell-based electric vehicles are analyzed in the paper. Following that a conventional topology based on fuel cell and battery using a DC/DC converter with the connection between the fuel cell and the inverter, and a floating voltage topology powered by fuel cell and supercapacitor without any DC/DC converters are chosen for the simulation analysis. Simulation results show that power variations of the fuel cell in floating voltage topology can be smoother, and its rated power is downsized, which can extend the fuel cell lifetime and take full advantages of the fuel cell and the supercapacitor.