Abstract: An embodiment residual water drain system of a fuel cell vehicle includes a fuel cell, a drain device configured to drain residual water from the fuel cell, and a controller configured to drain the residual water from the fuel cell through the drain device, to turn off the fuel cell, and to convert a vehicle into an EV mode, when charging the vehicle with hydrogen is determined to be necessary.

Abstract: A system and a method of draining residual water of a fuel cell for a vehicle are proposed. The system includes a fuel cell; an outdoor temperature sensor measuring an outdoor temperature; a drainer draining residual water in the fuel cell; and a controller previously controlling the drainer to drain the residual water in the fuel cell before parking of the vehicle is completed or an operation of the fuel cell is terminated, when a parking available situation is detected during driving of the vehicle in a state where the outdoor temperature is equal to or less than a reference temperature.

Abstract: A system and method for calibrating an offset of a pressure sensor for a fuel cell including one or more fuel cell modules in which power generation is individually controlled by independently supplying hydrogen or air to a fuel cell stack includes a pressure sensor to sense a pressure of the hydrogen supplied to the fuel cell stack, a monitoring unit which monitors whether offset calibration of the pressure sensor of the one or more fuel cell modules is required, a power generation control unit which individually controls the one or more fuel cell modules to continue or stop power generation, and a calibration control unit which calibrates the offset of the pressure sensor of the fuel cell module in a state where power generation is stopped based on a preset offset calibration period or the monitoring of the monitor unit as to whether calibration is required.

Abstract: A system and method for controlling a discharge of residual water remaining in a fuel cell stack after an operation of a fuel cell is ended is provided. The method includes determining whether a preset temperature condition is satisfied, determining whether a preset time condition is satisfied when the temperature condition is satisfied, and discharging residual water in a fuel cell stack while a vehicle travels when the temperature condition and the time condition are satisfied.

Abstract: A method of calibrating an offset of a pressure sensor, by which an offset of a sensing value of a pressure sensor, which detects a pressure of hydrogen in a fuel cell system, is accurately calibrated. The method includes receiving, by a controller, a sensing value of a pressure sensor which detects a hydrogen pressure in a state where a hydrogen supply starts after a start of a fuel cell system; counting, by the controller, a time for which the sensing value of the pressure sensor increases from a first pressure P1 to a second pressure P2; calculating, by the controller, an offset value corresponding to the counted time by use of stored setting data; and calibrating, by the controller, a subsequent sensing value of the pressure sensor by the calculated offset value in real time when the offset value is calculated.

Abstract: A system for measuring the insulation resistance of a fuel cell vehicle is provided. The system includes a fuel cell that supplies power, a rechargeable high-voltage battery, and a bidirectional converter, disposed between an output terminal of the fuel cell and the high-voltage battery, to adjust a voltage at the output terminal of the fuel cell. A fast measurement unit measures the insulation resistance of the fuel cell vehicle by being connected to the output terminal of the fuel cell and a second measurement unit measures the insulation resistance of the fuel cell vehicle by being connected to the output terminal of the high-voltage battery. A controller operates the bidirectional converter based on the state of the fuel cell vehicle and measure the insulation resistance of the fuel cell vehicle using the first measurement unit or the second measurement unit.

Abstract: A method of calibrating an offset of a pressure sensor, by which an offset of a sensing value of a pressure sensor, which detects a pressure of hydrogen in a fuel cell system, is accurately calibrated. The method includes receiving, by a controller, a sensing value of a pressure sensor which detects a hydrogen pressure in a state where a hydrogen supply starts after a start of a fuel cell system; counting, by the controller, a time for which the sensing value of the pressure sensor increases from a first pressure P1 to a second pressure P2; calculating, by the controller, an offset value corresponding to the counted time by use of stored setting data; and calibrating, by the controller, a subsequent sensing value of the pressure sensor by the calculated offset value in real time when the offset value is calculated.

Abstract: A method and system for controlling a fuel cell vehicle are provided. The method includes determining, by a controller, a driving pattern of a driver based on driving information including acceleration and deceleration information. A condition for activation of an idling-stop of a fuel cell is then set based on the determined driving pattern and the fuel cell is stopped from generating electric energy when the condition for activation of the idling-stop is satisfied.

Abstract: A system for measuring the insulation resistance of a fuel cell vehicle is provided. The system includes a fuel cell that supplies power, a rechargeable high-voltage battery, and a bidirectional converter, disposed between an output terminal of the fuel cell and the high-voltage battery, to adjust a voltage at the output terminal of the fuel cell. A fast measurement unit measures the insulation resistance of the fuel cell vehicle by being connected to the output terminal of the fuel cell and a second measurement unit measures the insulation resistance of the fuel cell vehicle by being connected to the output terminal of the high-voltage battery.

Abstract: A control method of a cooling water pump of fuel cell vehicle is provided. The method includes comparing a derived temperature value, including a cooling water temperature of a fuel cell or an estimated temperature of a stack of the fuel cell, with predetermined temperature criteria and comparing a required output value of the stack of the fuel cell with predetermined output criteria. The cooling water pump is then operated in a normal mode when the derived temperature value is greater than the temperature criteria or when the required output value is greater than the output criteria. Additionally, the cooling water pump is operated in a stop mode when the derived temperature value is less than the temperature criteria and, simultaneously, when the required output value is less than the output criteria.

Abstract: An emergency start method for a fuel cell-powered vehicle includes starting the vehicle and detecting an abnormal state of a power supply system of an air blower upon the start of the vehicle. If the power supply system of the air blower is in the abnormal state, an air-check valve of a fuel cell opens. Hydrogen is supplied to the fuel cell, and the air blower operates with power generated from the fuel cell and an emergency start system.

Abstract: A control method of a cooling water pump of fuel cell vehicle is provided. The method includes comparing a derived temperature value, including a cooling water temperature of a fuel cell or an estimated temperature of a stack of the fuel cell, with predetermined temperature criteria and comparing a required output value of the stack of the fuel cell with predetermined output criteria. The cooling water pump is then operated in a normal mode when the derived temperature value is greater than the temperature criteria or when the required output value is greater than the output criteria. Additionally, the cooling water pump is operated in a stop mode when the derived temperature value is less than the temperature criteria and, simultaneously, when the required output value is less than the output criteria.

Abstract: A method and system for controlling a fuel cell vehicle are provided. The method includes determining, by a controller, a driving pattern of a driver based on driving information including acceleration and deceleration information. A condition for activation of an idling-stop of a fuel cell is then set based on the determined driving pattern and the fuel cell is stopped from generating electric energy when the condition for activation of the idling-stop is satisfied.

Abstract: A driving control method and system for a fuel cell vehicle are provided. The driving control method includes monitoring, by a vehicle controller, information regarding vehicle conditions and entering a minimum driving mode when the monitored vehicle conditions meet minimum-driving-mode entry conditions. A temperature of a fuel cell stack detected and then adjusted when the determined temperature of the fuel cell stack is different from a preset target stack temperature value, to match the temperature of the fuel cell stack with the preset target stack temperature.

Abstract: A driving control method and system for a fuel cell vehicle are provided. The driving control method includes monitoring, by a vehicle controller, information regarding vehicle conditions and entering a minimum driving mode when the monitored vehicle conditions meet minimum-driving-mode entry conditions. A temperature of a fuel cell stack detected and then adjusted when the determined temperature of the fuel cell stack is different from a preset target stack temperature value, to match the temperature of the fuel cell stack with the preset target stack temperature.

Abstract: A method for controlling a cold start of a fuel cell vehicle includes detecting and storing temperatures at an inlet and an exit of fuel cell cooling water a plurality of times after turning-off of the fuel cell vehicle. A start sequence is controlled based on the lowest temperature of the stored temperatures and temperatures at the inlet and exit of the cooling water at a restart of the vehicle. Accordingly, it is possible to enhance start-up stability and driving stability by controlling a cold start sequence according to an internal state of the fuel cell stack.

Abstract: A method and apparatus for controlling charge of a low-voltage battery are provided. The method includes assigning, by a controller, a preset voltage for the low-voltage battery based on an operating mode of a vehicle and a charge state of a high-voltage battery. In addition, the controller compares the preset voltage with a present charge voltage of the low-voltage battery and increases the present charge voltage with a first slope until the present charge voltage becomes equal to the preset voltage when the preset voltage is greater than the present charge voltage. The operating mode comprises drive modes that include a first drive mode and a second drive mode, a fuel cell stop mode, and an emergency mode. The first drive mode is divided into a plurality of stages based on the charge state of the high-voltage battery.

Abstract: An emergency start method for a fuel cell-powered vehicle includes starting the vehicle and detecting an abnormal state of a power supply system of an air blower upon the start of the vehicle. If the power supply system of the air blower is in the abnormal state, an air-check valve of a fuel cell opens. Hydrogen is supplied to the fuel cell, and the air blower operates with power generated from the fuel cell and an emergency start system.

Abstract: A method and apparatus for controlling charge of a low-voltage battery are provided. The method includes assigning, by a controller, a preset voltage for the low-voltage battery based on an operating mode of a vehicle and a charge state of a high-voltage battery. In addition, the controller compares the preset voltage with a present charge voltage of the low-voltage battery and increases the present charge voltage with a first slope until the present charge voltage becomes equal to the preset voltage when the preset voltage is greater than the present charge voltage. The operating mode comprises drive modes that include a first drive mode and a second drive mode, a fuel cell stop mode, and an emergency mode. The first drive mode is divided into a plurality of stages based on the charge state of the high-voltage battery.

Abstract: A method for controlling a cold start of a fuel cell vehicle includes detecting and storing temperatures at an inlet and an exit of fuel cell cooling water a plurality of times after turning-off of the fuel cell vehicle. A start sequence is controlled based on the lowest temperature of the stored temperatures and temperatures at the inlet and exit of the cooling water at a restart of the vehicle. Accordingly, it is possible to enhance start-up stability and driving stability by controlling a cold start sequence according to an internal state of the fuel cell stack.