Patent ID: 8088526
Filing Date: 2012-01-03
Classification: H01M,Y02E

Abstract:
1. A fuel cell system configured to operate under anode flow shifting, said system comprising: a first split sub-stack; a second split sub-stack; first and second hydrogen sources providing fresh hydrogen to the first and second sub-stacks; a first anode bleed valve positioned proximate to an anode input of the first split sub-stack and a second anode bleed valve positioned proximate to an anode input of the second split sub-stack; a voltage measuring circuit for measuring the voltage of fuel cells in the first and second split sub-stacks; and a controller responsive to voltage signals from the voltage measuring circuit, said controller determining a fuel cell voltage spread for both the first and second sub-stacks, said controller suspending the anode flow shifting and causing fresh hydrogen to only be sent to the first or second sub-stack if the cell voltage spread of the first or second sub-stack is greater than a first predetermined threshold and causing fresh hydrogen to be sent to the first or second sub-stack and an anode bleed from the other of the first or second sub-stack if the cell voltage spread is greater than a second predetermined threshold that is larger than the first predetermined threshold.