Fuel cell system and method to operate a fuel cell system

[0038] In FIG. 1, the entirety of a first embodiment example of a fuel cell system according to the invention is labeled 10. It comprises fuel cell 12, which is operated in a manner known in the art to generate power from a fuel gas, e.g., hydrogen, and an oxidant, e.g., oxygen, which is obtained from supplied ambient air. The fuel cell is a PEM fuel cell (PEM: Proton Exchange Membrane), i.e., a fuel cell with a proton exchange membrane. The fuel cell 12 possesses an anode side 14 and a cathode side 16, which are separated by the proton exchange membrane 18.

[0039] The fuel cell system 10 further comprises reformer 20, which is arranged on the anode side and generates a fuel gas from a starting gas, e.g., a hydrocarbon. A compressor 22 is connected upstream of the reformer 20, whereby the compressor—due to being associated with the anode side 14 of the fuel cell 12—hereafter will be referred to as the anode compressor 22.

[0040] The fuel cell system 10 is also equipped with a compresso