Method and apparatus for controlling a fuel cell

Abstract

A fuel cell power supply system includes a fuel cell and a converter which converts the DC output power of the fuel cell into the corresponding AC output power. A reduced-size converter or invertor may be employed by following the sequence consisting of checking to see whether there is an open-circuit voltage at the start-up of the fuel cell, followed by reducing the voltage across the fuel cell by using a discharging resistor and then rendering the converter or inverter operational. A switch is included, which is normally closed and selectively connects the discharging resistor and the fuel cell in parallel. This allows the fuel cell to continue to discharge when the fuel cell or system has been terminated normally or in case the appropriate control power supply should fail. The fuel cell is thus protected against any degradation that may occur due to any residual FC gas that may remain in the fuel cell and conduit passages, by allowing any voltage caused by the residual FC gas to discharge rapidly.

Dependencies are inferred from the claim text.