Patent ID: 8247126

Claim:
A method of controlling pressure of a fuel gas in a fuel cell stack having a pressure control device for regulating pressures of said fuel gas and an oxidant gas entering said fuel cell stack, said method comprising: establishing a specification for a fuel gas/oxidant gas delta pressure vs. time value based solely on pressures of hydrogen and oxygen entering said fuel cell stack over time; operating said fuel cell stack, wherein said pressure control device normally maintains said fuel gas and said oxidant gas entering said fuel cell stack at pressures maintaining said fuel gas/oxidant gas delta pressure vs. time value within said specification; monitoring said fuel gas/oxidant gas delta pressure vs. time value; determining excessive pressure of hydrogen in said fuel cell stack based solely on said specification for a fuel gas/oxidant gas delta pressure vs. time value; and reducing stress resulting from excessive pressure of the fuel gas by implementing at least one of the following: inducing said fuel cell stack to convert excess fuel gas into electrical current, shutting off supply of said fuel gas to said fuel cell stack, and raising an operating pressure of said fuel cell stack when said fuel gas/oxidant gas delta pressure vs. time value strays beyond said specification.