Patent ID: 6406806
Filing Date: 2002-06-18
Classification: B60L,H01M,Y02E,Y02T

Abstract:
In a method for operating a fuel cell system having a fuel processor which supplies a hydrogen-rich stream to a stack of fuel cells, wherein said hydrogen reacts with oxygen to supply electrical power to an external load, the improvement comprising:(a) monitoring the voltage of at least one of said cells; (b) comparing said monitored voltage to first and second preselected values that are selected based on a value of the external load, where the second preselected value is less than the first preselected value; (c) generating a first signal if said monitored voltage is less than said first preselected value and greater than or equal to said second preselected value; (d) generating a second signal if said monitored voltage is less than said second preselected voltage; (e) reducing the external load when said first signal is generated; and (f) terminating the supply of power to the external load when said second signal is generated.