To provide a device and a method for monitoring performance of a fuel cell stack.
The voltage of a fuel cell 4 in a stack 2 is monitored by using opt-isolators 14-20 equipped with light emitters 22 and plural photo-detectors 24 forming a row 40 being connected in series, and when an abnormal condition occurs, a warning is issued or a correcting action is started. When all fuel cells are normal, all light emitters 22 emit light, and all photo detectors 24 in the row 40 are closed, in order to pass a constant current in the row 40. If at least one fuel cell malfunctions, since a voltage of the fuel cell is lowered below a start voltage of the light emitter and the related light emitter disappears, the photo detector relating to the light emitter is opened, in order to cut off the current in the row. Thereby, a warning is issued or an action to protect the defective fuel cell is started.
CLINGERMAN BRUCE JEFFREY
MOWERY KENNETH DAVID
