US 11,658,319 B2
Method of operating fuel cell system
Atsushi Kamachi, Wako (JP); Akane Goto, Wako (JP); and Ryo Kobayashi, Wako (JP)
Assigned to Honda Motor Co., Ltd., Tokyo (JP)
Filed by HONDA MOTOR CO., LTD., Tokyo (JP)
Filed on Feb. 8, 2022, as Appl. No. 17/667,116.
Claims priority of application No. JP2021-028586 (JP), filed on Feb. 25, 2021.
Prior Publication US 2022/0271312 A1, Aug. 25, 2022
Int. Cl. H01M 8/04746 (2016.01); H01M 8/04537 (2016.01); H01M 8/0438 (2016.01)
CPC H01M 8/04753 (2013.01) [H01M 8/04559 (2013.01); H01M 8/04619 (2013.01); H01M 2250/20 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A method of operating a fuel cell system comprising a fuel cell stack including a plurality of power generation cells stacked together, the power generation cells being configured to generate power based on supply of an anode gas and a cathode gas, the method comprising:
a stable-period voltage difference calculation step of, in a state where output power of the fuel cell stack is stable, calculating a stable-period voltage difference obtained by subtracting a minimum cell voltage among cell voltages of the plurality of power generation cells from an average cell voltage obtained by averaging the cell voltages of the plurality of power generation cells;
a voltage difference calculation step of, during power generation of the fuel cell stack after the stable-period voltage difference calculation step, calculating a voltage difference obtained by subtracting a minimum cell voltage among cell voltages of the plurality of power generation cells from an average cell voltage obtained by averaging the cell voltages of the plurality of power generation cells;
a determination step of calculating a change amount of the voltage difference with respect to the stable-period voltage difference, and determining whether or not the change amount has exceeded a predetermined threshold value;
a continuous power generation step of generating power without changing a supply amount of the anode gas to the fuel cell stack if it is determined that the change amount is equal to or less than the predetermined threshold value;
an increased-anode-gas power generation step of generating power by increasing the supply amount of the anode gas to the fuel cell stack so as to be larger than the supply amount of the anode gas of the continuous power generation step if it is determined that the change amount has exceeded the predetermined threshold value;
an increased-cathode-gas power generation step of increasing a supply amount of the cathode gas to the fuel cell stack, prior to the increased-anode-gas power generation step; and
a re-determination step of re-determining whether or not the change amount remains in excess of the predetermined threshold value after the increased-cathode-gas power generation step.
wherein:
if the determination step determines that the change amount has exceeded the predetermined threshold value, the increased-cathode-gas power generation step and the re-determination step are performed;
if the re-determination step determines that the change amount is equal to or less than the predetermined threshold value, the increased-cathode-gas power generation step is stopped and the continuous power generation step is performed; and
if the re-determination step determines that the change amount remains in excess of the predetermined threshold value, the increased-anode-gas power generation step is performed.