Abstract: The present invention provides a purge system for a fuel cell, which can reduce the time required to thaw a frozen valve during cold start-up and reduce the whole start-up time, thus improving the cold start performance. In preferred embodiments, the present invention provides a purge system for a fuel cell with improved cold start performance, the system preferably including a main pipe connected to a purge gas outlet of a fuel cell stack to discharge a purge gas purging the fuel cell stack and impurities; an auxiliary pipe branched from the main pipe; a purge valve installed in each of the main pipe and the auxiliary pipe to perform an purge operation; a cut-off valve installed at an upstream side of the purge valve in the auxiliary pipe; and a controller for controlling the operation of the purge valves and the cut-off valve.

Abstract: The present invention provides a method for controlling output of a fuel cell to improve fuel efficiency of a fuel cell hybrid vehicle, in which the fuel cell is operated at a constant power at a maximum efficiency point, wherein the fuel cell and a storage means are directly connected if the output and energy of the storage means is insufficient, and the power generation of the fuel cell is stopped when the level of energy of the storage means is increased during stopping or during low power operation such that the fuel cell is intensively operated at the maximum efficiency point, thus improving the fuel efficiency of the fuel cell and the efficiency of the fuel cell system.

Abstract: The present invention provides a separator for a fuel cell, in which a water discharge hole such as a venturi tube or a water discharge means including a metal plate for condensing water is provided on a land of the separator being in contact with a gas diffusion layer (GDL) of a fuel cell so that water generated by a reaction is easily discharged from the GDL through the water discharge means.

Abstract: The present invention provides a power configuration system for a fuel cell hybrid vehicle and a method for controlling the same, in which a second blocking diode is installed in a main bus terminal at an output terminal of a fuel cell (in front of a first blocking diode) separately from the existing first blocking diode installed in the main bus terminal, the positions of high voltage components for driving the fuel cell are changed from the rear of the first blocking diode to the front of the first blocking diode, and the operations of the high voltage components are appropriately controlled during regenerative braking such that the voltage of the fuel cell may be maintained below that of the supercapacitor.

Abstract: The present invention provides a hybrid fuel cell system that is configured to determine if an idle stop condition has been satisfied during a normal operation mode of the hybrid fuel cell system, cut off air supply to a fuel cell to stop power generation of the fuel cell and reduce a voltage which the fuel cell outputs in response to determining that the idle stop condition has been satisfied. The voltage of a bidirectional converter, connected between a battery and a bus terminal is reduced and the output of the fuel cell is controlled, based on a first predetermined value and maintained at that first predetermined value. Subsequently, the battery is charged via the output current of the fuel cell generated by maintaining the reduced voltage of the bidirectional converter.

Abstract: A method of estimating a salt contamination is provided. The method includes preparing salt contamination data measured at a plurality of areas, preparing geographical factor data of areas for estimating, preparing rainfall amount data near the areas, setting a correlation expression having the geographical factor and the rainfall amount as variables, and estimating salt contamination of the areas for estimating according to the rainfall amount.

Abstract: The present invention provides an improved method for determining the amount of reactant gases supplied to a fuel cell system to ensure a stable supply of reactant gases to a fuel cell stack. In particularly, the present invention estimates an output current value of a fuel cell stack by detecting the state of charge of an electricity storage device connected in parallel to the fuel cell stack; measures a target current value according to the amount of output required by a driver; determines the amount of reactant gases to be supplied by comparing the estimated output current value and the target current value; and supplies the determined amount of reactant gases to the fuel cell stack.

Abstract: The present invention provides a current collector of an end plate for a fuel cell and a method for controlling the same, in which a plurality of current collector plates having different resistance values is mounted on an end plate so that the current of a fuel cell is consumed during cold start and during low power operation to improve cold startability of the fuel cell and, further, the durability of a membrane electrode assembly (MEA) is improved due to an increase in voltage during low power operation.

Abstract: The present invention provides an idle stop-start control method of a fuel cell hybrid vehicle including a fuel cell as a main power source and a storage means as an auxiliary power source, in which air and hydrogen supply is cut off during low power operation where the efficiency of the fuel cell is low and during regenerative braking such that residual oxygen and hydrogen are consumed to drop the voltage of a fuel cell stack, thus stopping the operation of the fuel cell.

Abstract: Features is a fuel cell system including: a stack consisting of a plurality of unit cells generating electrical energy by means of electrochemical reaction of a fuel and an oxidizing agent; a fuel supply connected to the stack through a first connecting line to supply the fuel to the stack; an oxidizing agent supply connected to the stack through a second connecting line to supply the oxidizing agent to the stack; a burner mounted on the second connecting line and generating heat by means of oxidizing catalytic reaction of the fuel and oxidizing agent; a mixing valve mounted on a third connecting line which connects the first connecting line with the second connecting line and supplying the fuel and the oxidizing agent to the burner; and a heater mounted at the burner, generating heat by electricity, and supplying the heat to the burner.

Abstract: The present invention provides a method for determining the occurrence of ice blocking in an electrode surface in real time by analyzing minimum cell voltages of a fuel cell stack and, at the same time, distinguishing the occurrence of ice blocking in an anode from the occurrence of ice blocking in a cathode.

Abstract: The present invention provides a purge system for a fuel cell, which can reduce the time required to thaw a frozen valve during cold start-up and reduce the whole start-up time, thus improving the cold start performance. In preferred embodiments, the present invention provides a purge system for a fuel cell with improved cold start performance, the system preferably including a main pipe connected to a purge gas outlet of a fuel cell stack to discharge a purge gas purging the fuel cell stack and impurities; an auxiliary pipe branched from the main pipe; a purge valve installed in each of the main pipe and the auxiliary pipe to perform an purge operation; a cut-off valve installed at an upstream side of the purge valve in the auxiliary pipe; and a controller for controlling the operation of the purge valves and the cut-off valve.

Abstract: A method for shutting down a fuel cell system includes: determining whether an outside air temperature is below a first predetermined reference temperature when a shutdown of a fuel cell system is detected; warming up the fuel cell stack by operating balance of plant components of the fuel cell system and a stack load using the power of the fuel cell stack, while the supply of hydrogen to the fuel cell stack is normally maintained, when the outside air temperature is below the first reference temperature; removing water in the fuel cell stack by passing air supplied by an air supply system through the stack load to supply heated air to a cathode of the fuel cell stack; and shutting down the fuel cell system by cutting off the supply of air after the removal of water. The method can eliminate or reduce cold start failure.

Abstract: A power-down control method of a fuel cell hybrid vehicle includes determining an operation mode when a key-off command is input. If the mode is a fuel cell mode, the method includes: converting a low voltage DC-DC converter connected to an auxiliary battery to a boost mode; maintaining a driving state of a high voltage part, powered by voltage from the auxiliary battery and boosted by the low voltage DC-DC converter; subsequently stopping operation of a fuel cell stack and turning off the high voltage part; and subsequently turning off the low voltage DC-DC converter. If the mode is a hybrid mode, the method includes: maintaining a driving state of the high voltage part, powered by voltage from a super capacitor; subsequently stopping operation of the fuel cell stack and turning off the high voltage part; subsequently turning off the DC-DC converters; and subsequently cutting power of the super capacitor.

Abstract: The present invention provides a fuel cell hybrid system having a multi-stack structure, which maintains the voltage of a fuel cell at a level lower than that of an electricity storage means (supercapacitor) during regenerative braking so that the fuel cell does not unnecessarily charge the electricity storage means, thereby increasing the amount of recovered energy and improving fuel efficiency.

Abstract: The present invention provides a separator for a fuel cell, in which a water discharge hole such as a venturi tube or a water discharge means including a metal plate for condensing water is provided on a land of the separator being in contact with a gas diffusion layer (GDL) of a fuel cell so that water generated by a reaction is easily discharged from the GDL through the water discharge means.

Abstract: The present invention provides a current collector of an end plate for a fuel cell and a method for controlling the same, in which a plurality of current collector plates having different resistance values is mounted on an end plate so that the current of a fuel cell is consumed during cold start and during low power operation to improve cold startability of the fuel cell and, further, the durability of a membrane electrode assembly (MEA) is improved due to an increase in voltage during low power operation.

Abstract: The present invention provides a power configuration system for a fuel cell hybrid vehicle and a method for controlling the same, in which a second blocking diode is installed in a main bus terminal at an output terminal of a fuel cell (in front of a first blocking diode) separately from the existing first blocking diode installed in the main bus terminal, the positions of high voltage components for driving the fuel cell are changed from the rear of the first blocking diode to the front of the first blocking diode, and the operations of the high voltage components are appropriately controlled during regenerative braking such that the voltage of the fuel cell may be maintained below that of the supercapacitor.

Abstract: The present invention provides an idle stop-start control method of a fuel cell hybrid vehicle including a fuel cell as a main power source and a storage means as an auxiliary power source, in which air and hydrogen supply is cut off during low power operation where the efficiency of the fuel cell is low and during regenerative braking such that residual oxygen and hydrogen are consumed to drop the voltage of a fuel cell stack, thus stopping the operation of the fuel cell.

Abstract: The present invention provides a method for controlling output of a fuel cell to improve fuel efficiency of a fuel cell hybrid vehicle, in which the fuel cell is operated at a constant power at a maximum efficiency point, wherein the fuel cell and a storage means are directly connected if the output and energy of the storage means is insufficient, and the power generation of the fuel cell is stopped when the level of energy of the storage means is increased during stopping or during low power operation such that the fuel cell is intensively operated at the maximum efficiency point, thus improving the fuel efficiency of the fuel cell and the efficiency of the fuel cell system.