Patent ID: 9728798
Date: 2017-08-08
CPC Classifications: H01M,Y02E,Y02T

Claim:
1. A control method for a fuel cell system equipped with: a fuel cell that has a membrane electrode assembly which includes an electrolyte membrane, and an internal reactant gas passage through which reactant gas supplied to and discharged from the membrane electrode assembly flows; a retained water quantity grasping unit that detects or estimates an actual retained water quantity which is a current quantity of retained water retained in the internal reactant gas passage; and a power generation control unit that controls power generation of the fuel cell, the control method comprising: a step of, when the actual retained water quantity is equal to or more than a flooding threshold, by means of the power generation control unit, causing the system to be actuated in a normal-time drying mode in which the fuel cell is caused to generate electric power while being dried more than in a normal-time mode in which the fuel cell is caused to normally generate electric power in response to a required load, until the actual retained water quantity is decreased to a normal-time target retained water quantity; and a step of, when the actual retained water quantity is equal to or more than the flooding threshold at a time of detection of a system stop instruction, by means of the power generation control unit, causing the system to be actuated in a stop-time drying mode in which the fuel cell is caused to generate electric power while being dried more than in the normal-time drying mode until the actual retained water quantity is decreased to a stop-time target retained water quantity that is set to be smaller than the normal-time target retained water quantity.