Patent ID: 9240600
Filing Date: 2016-01-19
CPC Classification: H01M,Y02E

Claim Text:
1. A method for limiting the output voltage of a PEM fuel cell system operating in an idling state in zero connected load conditions in such a way as to minimize degradation of performance over time, the PEM fuel cell system comprising an anode, a cathode, a controllable hydrogen recirculating pump, and a controllable oxygen recirculating pump, wherein the method comprises: (a) operating the PEM fuel cell system in zero connected load conditions; (b) supplying a stream of pure hydrogen to the anode of said fuel cell; (c) supplying an stream of pure oxygen to the cathode of said fuel cell; (d) monitoring an output voltage of the fuel cell; (e) monitoring a hydrogen pressure in the fuel cell; (f) monitoring an oxygen pressure in the fuel cell; (g) limiting the stream of hydrogen and the stream of oxygen and actuating the hydrogen and oxygen recirculating pumps in such a way as to bring and maintain the hydrogen and oxygen pressures below 0.7 bar