A fuel cell system and method for online determination and method for controlling the relative humidity of a reactant stream in a fuel cell stack

摘要

A fuel cell system (200) comprising: a fuel cell stack (202) having a plurality of fuel cells; a high frequency resistance measuring device (214) in electrical communication with the fuel cell stack (202), the high frequency resistance measuring device (214) adapted to measure a high frequency resistance HFR of the fuel cell stack (202); a humidity regulator (208, 210) in fluid communication with the fuel cell stack (202) adapted to adjust the relative humidity RH of a reactant stream in the fuel cell stack within a desired range; and a controller (212) in electrical communication with the radio frequency resistance measuring device (214) and the humidity controller (208, 210); characterized in that the controller (212) is arranged to control the humidity controller (208, 210) in response to the ratio d (HFR) / d (RH).