Method and system for power control in an automotive vehicle

Abstract

A method for controlling a vehicle including a fuel cell system and an energy storage unit includes, if the fuel cell system is charging the energy storage unit, determining an average ratio of (i) a change in energy stored in the energy storage unit and (ii) a mass of hydrogen consumed by the fuel cell system to generate the change in energy stored in the energy storage unit. The method also includes, if the fuel cell system is not charging the energy storage unit, selecting a target operating power for the fuel cell system based on vehicle power demand and the determined ratio that sufficiently minimizes drive cycle hydrogen consumption by the fuel cell system.

What is claimed: 
     
         1 . A method for controlling a hybrid fuel cell vehicle including a fuel cell system and an energy storage unit, the method comprising:
 determining a fuel cell system power to raise the state of energy of the energy storage unit and satisfy vehicle power demand that generally minimizes hydrogen consumption by the fuel cell system; and   operating the fuel cell system to generate the determined fuel cell system power.   
     
     
         2 . A method for controlling a hybrid fuel cell vehicle including a fuel cell system and an energy storage unit, the method comprising:
 determining a fuel cell system power needed to both raise the state of energy of the energy storage unit and satisfy vehicle power demand;   determining the minimum mass of hydrogen needed to satisfy the fuel cell system power; and   operating the fuel cell system to generate the fuel cell system power with the minimum mass of hydrogen.