Patent ID: 8828614

Claim:
A fuel cell hybrid system comprising: a fuel cell configured as a main power source wherein the fuel cell has a multi-stack structure in which a plurality of stacks are connected in series; an electricity storage means configured as an auxiliary power source; an air supply cutoff valve, wherein the air supply cut-off is disposed within an air supply pipe between the air blower and at least one stack of the plurality of stacks having the least amount of cells therein; and a controller configured to control the air supply cutoff valve to cut off air supplied by an air blower to one stack selected from the plurality of stacks during regenerative braking and to open the air supply cut off valve during normal operation so that air is supplied to all of the plurality of stacks, wherein the fuel cell is electrically connected to the electricity storage means so that electrical energy generated from the plurality of stacks is supplied to the electricity storage means during normal operation and a total voltage of the fuel cell becomes less than the voltage of the electricity storage means during regenerative braking by cutting off air supply to one of the plurality of stacks of the fuel cell by the air supply cut off valve.