Patent Document ID: 7867642
Application ID: 11553724
Patent Flag: 1

Claim One:
1. A method of managing a startup of a fuel cell stack to limit a minimum cell voltage and optimize a startup time, the method comprising the steps of: a. measuring a stack temperature in response to a request for stack startup; b. specifying a current density time profile based upon the stack temperature, a stored lowest membrane hydration and a stored average membrane hydration, wherein current density varies as time raised to the power of n (time″); c. calculating a voltage and a power density performance of an average cell with the average membrane hydration and a lowest cell with the lowest membrane hydration; d. if the average cell voltage is less than a predetermined minimum average voltage or if the lowest cell voltage is less than a predetermined minimum low voltage, reducing a ramp rate and repeating said steps b. and c.; f. if the average cell voltage is greater than the minimum average voltage plus a predetermined amount and the lowest cell voltage is greater than the minimum low voltage, increasing the ramp rate and repeating said steps b. and c.; and g. if the average cell voltage is in a range of the minimum average voltage plus the predetermined amount and the lowest cell voltage is equal to or greater than the minimum low voltage, using the current density time profile to start the stack.