Powering a fuel cell stack during standby

摘要

A system and method for limiting voltage cycling of a fuel cell stack during a stand-by mode by providing power from a battery to the stack while the stack is turned off. The method includes monitoring the voltage of each of the fuel cells in the fuel cell stack and determining an average cell voltage of the fuel cells in the fuel cell stack. The method also determines whether the average cell voltage of the fuel cells in the fuel cell stack has fallen below a predetermined voltage value and, if so, applies a voltage potential to the fuel cell stack to increase the average cell voltage above the predetermined voltage value.

主权项

1. A method for maintaining a voltage of a fuel cell stack in a fuel cell system above a desired voltage value, said fuel cell stack including a plurality of fuel cells, said method comprising:
monitoring the voltage of each of the fuel cells in the fuel cell stack; determining an average voltage of the voltages of each of the fuel cells in the fuel cell stack; determining whether the average voltage of the fuel cells in the fuel cell stack has fallen below a first predetermined voltage value; applying a voltage potential to the fuel cell stack to increase the average voltage above the first predetermined voltage value if the average voltage has fallen below the first predetermined voltage value; and determining whether the voltage of the fuel cell having a maximum cell voltage is above a second predetermined voltage value, wherein applying the voltage potential to the fuel cell stack includes applying the voltage potential to the fuel cell stack only if the maximum cell voltage is below the second predetermined voltage value regardless of whether the average voltage is below the first predetermined voltage value.