Abstract: A fuel cell stack enclosure includes: a lower housing disposed under a fuel cell stack and having a bottom plate portion provided with a water outlet therein; a sealing cap closing the water outlet from an outside of the lower housing; and an elastic member elastically pulling the sealing cap toward the bottom plate portion of the lower housing.

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 ventilation apparatus includes: a controller that determines whether insulation resistance between a fuel cell stack and an enclosure including the fuel cell stack is equal to or smaller than a preset value, and varies a degree of opening of a valve provided between an inlet provided on one side of the enclosure and an air blower injecting air to an interior of the enclosure through the inlet based on the determination.

Abstract: A fuel cell stack enclosure includes: a lower housing disposed under a fuel cell stack and having a bottom plate portion provided with a water outlet therein; a sealing cap closing the water outlet from an outside of the lower housing; and an elastic member elastically pulling the sealing cap toward the bottom plate portion of the lower housing.

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: Disclosed is a manifold block for a fuel cell, which provides excellent electrical insulation for a coolant flow channel in an internal flow channel. More specifically, a manifold block for a fuel cell stack, includes a coolant interface formed of a polymer insulating material and coolant flow channels; and a reactant gas interface formed of a metal material and including reactant gas flow channels. In particular, the reactant and coolant interfaces are mounted to a stack module and, at the same time, are integrally bonded to each other.

Abstract: Disclosed are an apparatus and a method for diagnosing a state of a fuel cell stack with high accuracy by reducing the deviation of a harmonic component although the voltage variation of the fuel cell stack is substantial. According to the present invention, a harmonic component is detected by converting the difference between the voltage of the fuel cell stack and a moving average voltage to a frequency and the state of the fuel cell stack is diagnosed based on the size of the detected harmonic component.

Abstract: A fuel cell stack is provided that includes a fuel cell stack module and an enclosure. The fuel cell stack module includes end plates and coupling bars coupled to the end plates. The enclosure includes an upper enclosure covering a front surface, an upper surface, and a back surface of the fuel cell stack module, a lower enclosure covering the front surface, a lower surface, and the back surface of the fuel stack module, a left enclosure fixed to one of the end plates, and a right enclosure fixed to the other of the end plates. The upper enclosure and the lower enclosure are coupled to protruding portions of the left enclosure and the right enclosure and bent toward the surfaces of the fuel cell stack module so as to be in surface contact with the surfaces of the fuel cell stack module.

Abstract: A failure diagnosis apparatus that includes an alternating current (AC) absorption unit that is connected to the fuel cell stack and switched based on an applied AC signal to enable a current from the fuel cell stack to flow. In addition, an AC signal generator is configured to generate the AC signal and supply the generated AC signal to the AC absorption unit. As the current from the fuel cell stack is absorbed by the AC absorption unit based on an alternating signal, a stack current input into a diagnosis processing unit includes an AC component, thus the diagnosis processing unit may diagnose fuel cell stack failure by analyzing a frequency of the AC component.

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: 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: An apparatus for insulating a plurality of exposed live parts of a fuel cell stack, includes a plurality of protectors. Each of the plurality of protectors is made of an insulating material and configured to insulate a corresponding one of the plurality of exposed live parts to which a corresponding one of current collector terminals disposed in an end plate of the fuel cell stack and a corresponding one of connections of a busbar are connected.

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: The present invention provides a manifold block for a fuel cell stack, coupled to a fuel cell stack module and having a gas passage and a cooling water passage. The manifold block includes an insulating member and an insulating cover. The insulating member is inserted into the cooling water passage and contacts an inner surface of the cooling water passage. The insulating member has a tube-like shape and electrically insulates the inner surface of the cooling water passage. The insulating cover is inserted into the cooling water passage and contacts an inner surface of the insulating member. The insulating cover fixes and protects the insulating member.

Abstract: A ventilation apparatus includes: a controller that determines whether insulation resistance between a fuel cell stack and an enclosure including the fuel cell stack is equal to or smaller than a preset value, and varies a degree of opening of a valve provided between an inlet provided on one side of the enclosure and an air blower injecting air to an interior of the enclosure through the inlet based on the determination.

Abstract: Disclosed are an apparatus and a method for diagnosing a state of a fuel cell stack with high accuracy by reducing the deviation of a harmonic component although the voltage variation of the fuel cell stack is substantial. According to the present invention, a harmonic component is detected by converting the difference between the voltage of the fuel cell stack and a moving average voltage to a frequency and the state of the fuel cell stack is diagnosed based on the size of the detected harmonic component.

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.

Abstract: Disclosed are a safety system of a fuel cell vehicle and a control method for the safety system. A safety system of a fuel cell vehicle using a fuel cell and a high voltage battery as a power source may include: a power switch disposed on a power wire connecting the power source and a power load to each other; an insulation resistance measuring device measuring an insulation resistance between the power wire and a chassis; and a controller controlling an operation of the power switch based on a measured insulation resistance measured by the insulation resistance measuring device. When the measured insulation resistance is equal to or less than a reference resistance, the controller enters a safe mode and the power switch is turned off to thereby block power supplied to the power load.

Abstract: A method for manufacturing a manifold for a fuel cell with a multilayer structure by injection-molding individual manifolds, each having welding projections and welding guides, and bonding the injection-molded individual manifolds by vibration welding includes arranging welding projections of an upper individual manifold and welding guides of a lower individual manifold to be engaged with each other while maintaining a uniform gap between each other to bond a plurality of individual manifolds in an up and down stacking structure, pressing the lower individual manifold upward, and applying vibration to the upper individual manifold in the left and right direction, thus bonding the upper and lower individual manifolds. Among the welding projections of the upper individual manifold, a non-horizontal welding projection whose longitudinal direction does not coincide with the vibration direction of the individual manifold has a variable height.