System and method for estimating hydrogen concentration of fuel cell

A system for estimating a hydrogen concentration of a fuel cell, the system comprising:

• the fuel cell;
• a discharge line connected to an outlet side of a fuel cell hydrogen electrode while connecting the fuel cell to an exterior of the fuel cell, for communication between the fuel cell and the exterior of the fuel cell;
• a discharge valve provided at the discharge line and configured to adjust the communication between the fuel cell and the exterior of the fuel cell;
• and
• a controller configured to estimate a gas discharge amount of gas discharged through the discharge line, to cut off the discharge valve after estimation of the gas discharge amount, to check occurrence of degradation of the fuel cell, and to correct a crossover coefficient value of the fuel cell in accordance with a level of the degradation in the fuel cell when the degradation of the fuel cell has occurred, estimating the hydrogen concentration in an interior of the fuel cell,
• wherein the controller is configured to determine a reduction amount reduced from the estimated gas discharge amount for a reference time after cut-off of the discharge valve, and then to determine whether or not the degradation of the fuel cell has occurred, based on the determined reduction amount, and
• wherein the controller is configured to determine a difference between the reduction amount of the gas discharge amount and a reference reduction amount of the gas discharge amount as a reduction variation amount, and then to conclude that the degradation has occurred in the fuel cell, when the determined reduction variation amount is greater than the reference reduction variation amount.