Abstract: A thermal management system for a fuel cell vehicle includes a first line including a coolant pump and a fuel cell stack, a second line including a coolant heater and a phase change material (PCM) and connected to the first line to form a first loop in which the coolant pump, the stack, the coolant heater, and the PCM are arranged, a third line including a radiator and connected to the first line to form a second loop in which the coolant pump, the stack, and the radiator are arranged, and an opening and closing valve opening and closing each of the first line, the second line, and the third line to allow the coolant to circulate in at least one of the first loop and the second loop, wherein the PCM is configured to be heat-exchanged with the coolant heater and the coolant.

Abstract: Disclosed are a fuel cell system and a method for controlling the same which enable performance recovery of a stack together with a high potential avoidance operation while operating the fuel cell system. The fuel cell system includes a fuel cell stack, in which a first separation plate having a first air flow path and a second separation plate having a second, different air flow path are alternately stacked with a membrane-electrode assembly interposed therebetween; and the method includes determining whether a high-potential avoidance operation is required while operating the fuel cell system including the fuel cell stack, and selectively supplying air to the air flow path of the first separation plate or the second separation plate when a high-potential avoidance operation is required, so as to easily achieve cathode performance recovery during the high-potential avoidance operation of the fuel cell system and the operation of the fuel cell system.

Abstract: A power net system for a fuel cell vehicle includes: a diode having a first end connected to an output stage of a fuel cell stack; a fuel cell load device branched and connected between the output stage of the fuel cell stack and the diode; a first relay positioned between the output stage of the fuel cell stack and the fuel cell load device and configured to connect or separate the output stage of the fuel cell stack and the fuel cell load device; and a second relay having a first end connected to a second end of the diode and a second end connected between the first relay and the fuel cell load device.

Abstract: A system and method of controlling an air blower for a fuel cell vehicle are provided. The method includes determining an operation amount of an air blower to secure a sufficient air flow rate under present operating conditions and obtaining information regarding clogging of an air channel or information regarding a back pressure using the operation amount of the air blower. In addition, a maximum operating range of the air blower is changed based on whether a present state is an air channel-clogged state or a back pressure-increased state.

Abstract: A system and method for emergency starting of a fuel cell vehicle is provided. In particular, a high-voltage converter, a balance of power (BOP), and a controller are included in the system. The high-voltage converter is configured such that one side thereof is connected to a high-voltage battery via a battery switch and the other side thereof is connected in parallel to a plurality of fuel cells. The BOP is connected in parallel to the high-voltage converter and the fuel cells. The controller is configured to control the power supplied from the high-voltage battery to the BOP without conversion by connecting the battery switch upon the failure of the high-voltage converter or high-voltage battery.

Abstract: Disclosed are a method and an apparatus for removing condensed water in a gas diffusion layer and a catalyst layer of a fuel cell. The method comprises steps of: a step of determining whether the condensed water is generated in the gas diffusion layer and the catalyst layer of the fuel cell; a step of reducing and supplying an amount of air supplied to a cathode of the fuel cell at a predetermined level, when it is determined that the condensed water is generated in the gas diffusion layer and the catalyst layer in the step of determining; a step of measuring a temperature of a stack of the fuel cell; and a step of increasing the amount of air supplied to the cathode of the fuel cell to an amount of air prior to being reduced at the predetermined operation level, when the measured temperature of the stack of the fuel cell is elevated to a predetermined temperature.

Abstract: A system and method for controlling a fuel cell of a vehicle are provided. The method includes sensing a time point when pressure control is necessary by sensing whether an output of the fuel cell is additionally necessary or whether the fuel cell can be in a dry-out state. In response to sensing that the pressure control is necessary, a required valve opening degree of an air outlet is derived by substituting a target air pressure for a data map. A fuel cell air outlet valve is then adjusted based the derived valve opening degree of the air outlet.

Abstract: A power net system for a fuel cell vehicle includes: a diode having a first end connected to an output stage of a fuel cell stack; a fuel cell load device branched and connected between the output stage of the fuel cell stack and the diode; a first relay positioned between the output stage of the fuel cell stack and the fuel cell load device and configured to connect or separate the output stage of the fuel cell stack and the fuel cell load device; and a second relay having a first end connected to a second end of the diode and a second end connected between the first relay and the fuel cell load device.

Abstract: A system and method for a cooling water control of a vehicle are provided. The method for a cooling water control of a vehicle includes detecting a flow rate of cooling water and comparing the detected flow rate with a preset normal flow rate value. When the detected flow rate of cooling water is less than the preset normal flow rate value a cooling water pump speed command is increased until a power average value of the cooling water pump reaches a reference power value when the cooling water is normally circulated to increase an RPM of the cooling water pump.

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 control method and system of a fuel cell system are provided. The control method includes draining the voltage of a fuel cell stack by charging a high voltage battery. In addition, the method includes draining the voltage of the fuel cell stack by connecting a fuel cell load device to the fuel cell stack, which is performed when the voltage of the fuel cell stack decreased by the first draining process is less than a predetermined first reference voltage.

Abstract: A system and method of controlling an air blower for a fuel cell vehicle are provided. The method includes determining an operation amount of an air blower to secure a sufficient air flow rate under present operating conditions and obtaining information regarding clogging of an air channel or information regarding a back pressure using the operation amount of the air blower. In addition, a maximum operating range of the air blower is changed based on whether a present state is an air channel-clogged state or a back pressure-increased state.

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: Disclosed are a method and an apparatus for removing condensed water in a gas diffusion layer and a catalyst layer of a fuel cell. The method comprises steps of: a step of determining whether the condensed water is generated in the gas diffusion layer and the catalyst layer of the fuel cell; a step of reducing and supplying an amount of air supplied to a cathode of the fuel cell at a predetermined level, when it is determined that the condensed water is generated in the gas diffusion layer and the catalyst layer in the step of determining; a step of measuring a temperature of a stack of the fuel cell; and a step of increasing the amount of air supplied to the cathode of the fuel cell to an amount of air prior to being reduced at the predetermined operation level, when the measured temperature of the stack of the fuel cell is elevated to a predetermined temperature.

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 system and method for emergency starting of a fuel cell vehicle is provided. In particular, a high-voltage converter, a balance of power (BOP), and a controller are included in the system. The high-voltage converter is configured such that one side thereof is connected to a high-voltage battery via a battery switch and the other side thereof is connected in parallel to a plurality of fuel cells. The BOP is connected in parallel to the high-voltage converter and the fuel cells. The controller is configured to control the power supplied from the high-voltage battery to the BOP without conversion by connecting the battery switch upon the failure of the high-voltage converter or high-voltage battery.

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 fuel cell system includes a stack constituted by a set of fuel cells. An air supplier supplies air to an air electrode of the fuel cell and a hydrogen supplier supplies hydrogen to a fuel electrode of the fuel cell. A connector connects an air supply route for supplying the air to the air electrode from the air supplier and a hydrogen supply route for supplying the hydrogen to the fuel electrode from the hydrogen supplier. The hydrogen is supplied to the air electrode through the connector when the stack operates at a low temperature, which is equal to or lower than an optimal operating temperature.

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: Disclosed is a method for detecting ice blocking of a fuel cell stack. In particular, the method includes periodically calculating a minimum cell voltage of a fuel cell stack from cell voltages measured by a cell voltage monitoring system while reactant gases are supplied to the fuel cell stack and then calculating a change in the minimum cell voltage using a currently calculated minimum cell voltage and a previous minimum cell voltage. It is then determined whether the change in the minimum cell voltage is above a predetermined reference value. When the change in the minimum cell voltage is above the reference value, it is determined that the ice blocking has occurred or is occurring in an anode of the fuel cell stack.