Patent ID: 8518593

Claim:
A method for controlling the operation of a fuel cell system at low temperature, the method comprising: determining, by a controller, whether the temperature of a fuel cell stack reaches a normal temperature; calculating, by the controller, when it is determined that the temperature of the fuel cell stack is lower than the normal temperature, a target temperature at a cathode outlet to maintain water present in a cathode of the fuel cell stack in a vapor phase based on information related to an operation state of the fuel cell stack detected by an operation state detection means; and calculating, by the controller, a target amount of coolant based on the calculated target temperature at the cathode outlet and the information related to the operation state of the fuel cell stack, and controlling the amount of coolant supplied to the fuel cell stack based on the calculated target amount of coolant, wherein the target temperature at the cathode outlet is calculated based on the information related to the operation state of the fuel cell stack including the amount of water generated in the cathode, which is calculated based on a stack current, the amount of air supplied to the cathode, and cathode inlet and outlet pressures, wherein the target amount of coolant is calculated based on the information related to the operation state of the fuel cell stack including a target temperature at a coolant outlet, which is obtained from the calculated target temperature at the cathode outlet, a coolant inlet temperature, and the amount of heat generated in the fuel cell stack.