In a fuel cell system, a controller is configured to, to stop the fuel cell system, (a) execute an oxidizing gas consumption process by supplying a fuel gas to an anode and sweeping current from a fuel cell while a supply-side on-off valve and an exhaust-side on-off valve are closed to seal the remaining oxidizing gas in the cathode, and (b) stop sweeping the current at a time point at which the difference between pressure of the cathode that decreases in response to the sweeping of the current and an estimated pressure value of the cathode that decreases by consumption of the oxidizing gas remaining in the cathode in response to the sweeping of the current becomes larger than a predetermined determination threshold value to end the oxidizing gas consumption process.

A fuel cell system includes a first plurality of fuel cells having a cathode and an anode. The plurality of fuel cells is configured to produce electrical power having a current and a voltage output. The plurality of fuel cells includes a first conductive plate and a second conductive plate. A shunt is electrically connected to the first conductive plate and the second conductive plate for shunting voltage output between the cathode and the anode. The shunt is mounted to, and supported by, the plurality of fuel cells. The shunt is connected to a control mechanism to control a shorting of one or more fuel cells of the plurality of fuel cells. The control mechanism is mounted to, and supported by, the plurality of fuel cells.

A fuel cell system includes a fuel cell stack, a gas liquid separator, a water level sensor, a drain valve, and a control unit. When a failure detection processing method is performed, a control unit makes a determination of main conditions where the water level sensor determines that water is present, a power generation current value of the fuel cell stack is not more than a predetermined current threshold value, a drain valve for discharging water in the gas liquid separator is open. Then, the control unit counts elapsed time when the main conditions are satisfied, and in the case where the main conditions are kept satisfied for the elapsed time which is larger than a time threshold value, the control unit determines that the water level sensor has a failure.

An operation control system and method of a fuel cell vehicle are provided. The system includes a fuel cell, an air supply device operated by a motor, to supply air to the fuel cell and a sensing unit that senses an abnormal operation of the air supply device. A calculation unit calculates a lower-limit voltage of the air supply device required for normal operation of the air supply device when the sensing unit senses abnormal operation of the air supply device. A controller then adjusts a voltage supplied to the air supply device based on the calculated lower-limit voltage.

A fuel cell power plant includes an energy storage system connected in parallel with a fuel cell system. The fuel cell system includes a controller, a fuel flow system, an air flow system, and an internal water management system. The controller is operable to receive, as inputs, the energy storage system state of charge and the power demand from an electric load. The controller is further operable to determine a power split set point and execute commands, as output, to control operation of the air flow system, wherein the air flow system actively regulates the proportion of current flow between the fuel cell system and the energy storage system to meet the power demand of the electric load.

Proposed are a fuel cell system and a method of controlling the fuel cell system. The fuel cell system includes: a hydrogen supply unit connected to a hydrogen inlet side of a fuel cell stack, with a supply valve and a sensor being provided in the hydrogen supply unit; a hydrogen discharge unit connected to a hydrogen outlet side of the fuel cell stack, with a water trap and a purge valve being provided in the hydrogen discharge unit; and a controller configured to calculate an amount of hydrogen discharged through the purge valve from an amount of hydrogen supplied to the fuel cell stack and an amount of hydrogen consumed therein, and to perform compensation control of the supply valve when the amount of the discharged hydrogen is at or above a reference value.

An apparatus configured for controlling emergency driving for a fuel cell vehicle may include a failure detector configured to detect whether a purge valve and a drain valve fails; a determination portion configured to measure voltages of channels of a fuel cell stack to determine whether stability of the fuel cell stack is secured; and a controller configured to control, when the stability of the fuel cell stack is not secured and a failure occurs on one or more of the purge valve and the drain valve, one or more of an operating pressure and an operating temperature of the fuel cell stack and a current applied to the fuel cell stack.

A method for controlling an output of a fuel cell stack is provided. The method includes calculating a total requirement current value to be output from a plurality of fuel cell stacks in a fuel cell electric vehicle (FCEV) including the plurality of fuel cell stacks. The calculated total requirement current value is then allocated to each fuel cell stack based on a voltage of the fuel cell stack.

A fuel cell system includes a fuel cell stack in which a plurality of unit cells is stacked, a detection unit configured to detect a cell voltage of at least one of the unit cells, a converter configured to regulate an output current of the fuel cell stack, and a control device configured to control the converter. The control device executes current reduction processing for reducing the output current in a stepwise manner when the cell voltage detected by the detection unit is a negative voltage.

A method for starting a fuel cell and to a fuel cell system which is configured to carry out the method. The fuel cell includes electrically conductive bipolar plates, arranged between which there is in each case a cathode, including a fluid-conducting cathode space, a membrane and an anode, including a fluid-conducting anode space. There is provision that the method includes the following steps in the specified order: purging the anode space with a fluid in order to expel fuel, impressing electricity on a unit composed of the cathode (2k)/membrane (1)/anode (2a) by applying a current and/or a voltage, wherein the fluid is applied to the anode space or continues to be so, switching off the electricity, and introducing a fuel into the anode space.