Abstract: A fuel cell having a structure for detachably mounting a cell-monitoring connector thereon includes separators arranged to be spaced apart from each other in a first direction, each of the separators including a receiving recess arranged in one side thereof, and hook-shaped gaskets respectively disposed on the separators and located around the receiving recess. The cell-monitoring connector includes a housing, at least a portion of the housing being received in a receiving space defined by the receiving recess, and connection terminals inserted into the housing to be connected to the separators. The housing includes a body inserted into the receiving space in a second direction that intersects the first direction, and a lever portion including a latching protrusion configured to be latched to or separated from a corresponding gasket among the hook-shaped gaskets by a pressing operation.

Abstract: A laser welding apparatus for laser-welding a first welding target and a second welding target seated on the first welding target includes a first jig on which the first welding target is seated, a second jig configured to press the first welding target such that the first welding target is adhered to the first jig, a third jig configured to press the second welding target such that the second welding target is adhered to the first welding target, one or more connection members connecting the second jig and the third jig such that the second welding target is pressed by the second jig when the first welding target is pressed by the first jig, and a laser head configured to laser-weld the first welding target and the second welding target by irradiating a laser beam to a specific welding part of the second welding target.

Abstract: A fuel cell stack is provided and includes a fuel cell assembly in which a plurality of fuel cells are stacked between upper and lower current collectors. The fuel cell stack includes an enclosure that pressurizes and seals the fuel cell assembly in a stacked direction of the fuel cells.

Abstract: A method and system for diagnosing a state of fuel cell are provided. The system includes a signal measurement unit that has a high pass filter with a predetermined cut-off frequency and a voltage measurement circuit, and that measures a first AC voltage to measure the fuel cell state diagnosis signal and a noise measurement unit including a band pass filter that has a predetermined pass band and a voltage measurement circuit, and that measures a second AC voltage to measure the fuel cell state diagnosis noise. A controller calculates a signal to noise ratio (SNR) of fuel cell state diagnosis data based on the first and second AC voltages, determines the corresponding fuel cell state diagnosis data to be reliable when the SNR value is greater than a predetermined reference value, and applies the fuel cell state diagnosis data to a control of a fuel cell vehicle.

Abstract: A fuel cell having a structure for detachably mounting a cell-monitoring connector thereon includes separators arranged to be spaced apart from each other in a first direction, each of the separators including a receiving recess arranged in one side thereof, and hook-shaped gaskets respectively disposed on the separators and located around the receiving recess. The cell-monitoring connector includes a housing, at least a portion of the housing being received in a receiving space defined by the receiving recess, and connection terminals inserted into the housing to be connected to the separators. The housing includes a body inserted into the receiving space in a second direction that intersects the first direction, and a lever portion including a latching protrusion configured to be latched to or separated from a corresponding gasket among the hook-shaped gaskets by a pressing operation.

Abstract: A manifold block mounted to a fuel cell stack for supplying and distributing air and hydrogen to the stack, the manifold block comprises: a main body including a hydrogen inlet, a hydrogen outlet, an air inlet and an air outlet; a hydrogen outlet cover welded to an outer surface of the main body and including a condensation chamber connected to the hydrogen outlet; an air inlet cover welded to an inner surface of the main body and including an air inflow portion connected to the air inlet; and an air outlet cover welded to the inner surface of the main body and including an air outflow portion connected to the air outlet.

Abstract: An end cell heater assembly includes: a case which has a first surface joined to an end plate of a fuel cell stack; a planar heating element installed in an accommodating groove formed in a second surface of the case; a terminal plate which is stacked and interposed between the planar heating element and an end cell of the fuel cell stack, joined and electrically connected to the end cell, and transferring heat generated by the planar heating element to the end cell; and a terminal which is integrally formed with the terminal plate so as to output electrical energy generated by the fuel cell stack and transferred through the terminal plate, to the outside.

Abstract: A bus plate unit is provided. The bus plate unit electrically connects a unit stack for a fuel cell having a (+) and a (?) stack terminal at both sides. The unit includes a (+) bus plate having a first end portion bent toward a first side surface of the unit stack and electrically coupled to a (+) stack terminal of the unit stack. A second end portion has a (+) bus terminal and abuts an upper first side of the unit stack. A (?) bus plate has a first end portion bent toward a second side surface of the unit stack and electrically coupled to the (?) stack terminal of the unit stack. A second end portion provides a (?) bus terminal and is proximate to the upper second side of the unit stack. An insulating layer encloses a surface of the (+) bus plate and the (?) bus plate.

Abstract: A method and system for diagnosing a state of fuel cell are provided. The system includes a signal measurement unit that has a high pass filter with a predetermined cut-off frequency and a voltage measurement circuit, and that measures a first AC voltage to measure the fuel cell state diagnosis signal and a noise measurement unit including a band pass filter that has a predetermined pass band and a voltage measurement circuit, and that measures a second AC voltage to measure the fuel cell state diagnosis noise. A controller calculates a signal to noise ratio (SNR) of fuel cell state diagnosis data based on the first and second AC voltages, determines the corresponding fuel cell state diagnosis data to be reliable when the SNR value is greater than a predetermined reference value, and applies the fuel cell state diagnosis data to a control of a fuel cell vehicle.

Abstract: A laser welding apparatus for laser-welding a first welding target and a second welding target seated on the first welding target includes a first jig on which the first welding target is seated, a second jig configured to press the first welding target such that the first welding target is adhered to the first jig, a third jig configured to press the second welding target such that the second welding target is adhered to the first welding target, one or more connection members connecting the second jig and the third jig such that the second welding target is pressed by the second jig when the first welding target is pressed by the first jig, and a laser head configured to laser-weld the first welding target and the second welding target by irradiating a laser beam to a specific welding part of the second welding target.

Abstract: A fuel cell stack is provided and includes a fuel cell assembly in which a plurality of fuel cells are stacked between upper and lower current collectors. The fuel cell stack includes an enclosure that pressurizes and seals the fuel cell assembly in a stacked direction of the fuel cells.

Abstract: A safety apparatus uses a fuel cell and a high voltage battery as a power source, and includes: a first voltage sensor that measures a voltage of a positive side of a voltage bus; a second voltage sensor that measures a voltage of a negative side of the voltage bus; and a controller that determines an electrical insulation between the positive side of the voltage bus and the electrical chassis based on the voltage of the positive side of the voltage bus and determines an electrical insulation between the negative side of the voltage bus and the electrical chassis based on the voltage of the negative side of the voltage bus.

Abstract: A method and system for diagnosing a state of fuel cell are provided. The system includes a signal measurement unit that has a high pass filter with a predetermined cut-off frequency and a voltage measurement circuit, and that measures a first AC voltage to measure the fuel cell state diagnosis signal and a noise measurement unit including a band pass filter that has a predetermined pass band and a voltage measurement circuit, and that measures a second AC voltage to measure the fuel cell state diagnosis noise. A controller calculates a signal to noise ratio (SNR) of fuel cell state diagnosis data based on the first and second AC voltages, determines the corresponding fuel cell state diagnosis data to be reliable when the SNR value is greater than a predetermined reference value, and applies the fuel cell state diagnosis data to a control of a fuel cell vehicle.

Abstract: An apparatus includes a stack voltage monitor that measures a voltage of each channel of a plurality of channels of a fuel cell stack. Each of the channel of the plurality of channels includes a predetermined number of unit cells. The stack voltage monitor calculates impedance of each of the channel from the measured voltage. The apparatus further includes a controller that diagnoses a state of the fuel cell stack based on the impedance of each of the channel.

Abstract: An apparatus and a method for discharging a residual electric energy of a fuel cell can rapidly discharge and remove a residual electric energy of a fuel cell for safety after the fuel cell is operated or when a collision is detected. The apparatus for discharging the residual electric energy of the fuel cell includes: a discharge relay connected with a fuel cell and turned on when starting or stopping a vehicle or a collision detecting sensor detects a collision; and a non-linear protecting element connected with the discharge relay in order to discharge a residual electric energy from the fuel cell.

Abstract: An apparatus for diagnosing a state of a fuel cell stack is provided. The apparatus may diagnose the state of the fuel cell stack without including the DC-DC converter which boosts the DC voltage and the inverter which converts the boosted DC voltage into the AC voltage. In particular, the apparatus may diagnose the state of the fuel cell by applying the rectangular wave of the single frequency having a duty ration of about 0.5 to the fuel cell stack, measuring the voltage of the fuel cell stack, detecting the even multiple harmonic component of the frequency of the rectangular wave by performing the frequency conversion on the measured voltage, and then diagnosing the state of the fuel cell stack based on the magnitude of the detected harmonic component.

Abstract: A fuel cell stack enclosure is provided that includes side covers configured to be joined with each of end of a stack module respectively. A lower cover is also configured to be provided under the stack module and formed to partially cover a lower portion and a first side portion of an outer surface of the side cove. An upper cover may be provided over the stack module, and be formed to partially cover an upper portion and a second side portion of the outer surface of the side cover to enclose the stack module along with the lower cover while joining with the side covers.

Abstract: A manifold block mounted to a fuel cell stack for supplying and distributing air and hydrogen to the stack, the manifold block comprises: a main body including a hydrogen inlet, a hydrogen outlet, an air inlet and an air outlet; a hydrogen outlet cover welded to an outer surface of the main body and including a condensation chamber connected to the hydrogen outlet; an air inlet cover welded to an inner surface of the main body and including an air inflow portion connected to the air inlet; and an air outlet cover welded to the inner surface of the main body and including an air outflow portion connected to the air outlet.

Abstract: An apparatus includes a stack voltage monitor that measures a voltage of each channel of a plurality of channels of a fuel cell stack. Each of the channel of the plurality of channels includes a predetermined number of unit cells. The stack voltage monitor calculates impedance of each of the channel from the measured voltage. The apparatus further includes a controller that diagnoses a state of the fuel cell stack based on the impedance of each of the channel.

Abstract: A system and method for diagnosing the state of a fuel cell stack are provided. The method includes simultaneously applying currents having respective first and second frequencies to a fuel cell stack and computing Fourier transforms of output currents and voltages from the fuel cell stack based on the applied currents. A real part of a first frequency impedance and an imaginary part of a second frequency impedance are calculated using amplitudes and phases of currents and voltages having the first frequency and the second frequency among the computed output currents and voltages. Further, a state of the fuel cell stack is determined by magnitude of the calculated real part of the first frequency impedance and by magnitude of the calculated imaginary part of the second frequency impedance.