A fuel cell system includes a fuel cell stack, an oxidizing gas supply system, a fuel gas supply system, a current control circuit configured to control an output current of the fuel cell stack, a control unit configured to control power generation of the fuel cell stack, and the output current of the current control circuit, the control unit controlling the current control circuit to adjust the output current thereby adjusting a heating value of the fuel cell stack; and a monitoring unit configured to monitor abnormal fuel gas generation, the abnormal fuel gas generation corresponding to a state where the fuel gas in excess of a predetermined allowable amount exists in the cathode. When the monitoring unit detects the abnormal fuel gas generation during execution of a warm-up operation to allow the fuel cell stack to generate heat with a predetermined target heating value, the control unit reduces the output current by reducing the target heating value.

A fuel cell system column includes a first terminal plate connected to a first electrical output of the column, a second terminal plate connected to a second electrical output of the column, at least one first fuel cell stack located in a middle portion of the column between the first terminal plate and the second terminal plate, and at least one electrical connection which is electrically connected to the middle portion of the column and which is configured to provide a more uniform fuel utilization across the first column.

The electric power supply device supplies electric power to a work machine. The electric power supply device includes a fuel cell and a utility connecting section for transferring utility to be utilized for an operation of a fuel cell between the work machine and the electric power supply device. A control device for controlling the electric power supply device for supplying electric power to the work machine includes a rated capability obtaining section for obtaining information indicating a rated value of a capability with which the work machine supplies the utility to the fuel cell in response to the electric power supply device being mounted in the work machine, or the electric power supply device being able to utilize the utility, and an operating condition determining section for determining an operating condition of the electric power supply device based on the rated value.

The present invention provides a technique capable of satisfying both the restoration of an output voltage of a fuel cell and an improvement of electric power responsiveness in a fuel cell system in a situation in which its operation status is restored to a normal operation from an operation having low power generation efficiency. A controller updates a lower limit voltage threshold in accordance with the restoration of an FC voltage until the operation status is restored to a normal operation from an operation having low power generation efficiency, such as an intermittent operation and a warmup operation (step S1). The controller increases an FC current in accordance with the updated lower limit voltage threshold (steps S2 and S3) to thereby satisfy both the requirements of the restoration of the output voltage of the fuel cell stack and the improvement of the electric power responsiveness.

A method of cleaning power cells in an array of power cells, comprising coupling at least one first power cell to second power cells in an array of power cells and causing the second power cells to drive the at least one first power cell with a voltage to clean catalyst on the at least one first power cell.

Disclosed is a control system for a fuel cell system that includes at least two or more fuel cell groups which each have at least one fuel cell connected in parallel. The fuel cell control system comprises: a unit level controller configured to control an output of an individual fuel cell; a group level controller configured to determine the output distribution of the individual fuel cells within the fuel cell group based on the performance decrease rates of the individual fuel cells within the fuel cell group; and a system level controller configured to determine the total output of the fuel cell system according to the power demand for the grid and determine the output distribution for each of the fuel cell groups in correspondence to the total output.

Introduced is an fuel cell power net including a fuel cell configured to generate power through a reaction between a fuel gas and an oxidizing gas, a power storage device configured to be charged with power generated by the fuel cell or discharged to supply power, a main line configured to electrically connect the fuel cell and the power storage device to each other; a main relay disposed on the main line so as to break or make an electrical connection between the fuel cell and the power storage device, a bypass line which is branched from the main line, bypasses the main relay, and is connected to the power storage device, a bypass relay disposed on the bypass line so as to break or make an electrical connection of the bypass line, and a controller configured to control the main relay or the bypass relay such that the power stored in the storage device is supplied to the fuel cell while the power generation of the fuel cell is stopped.

A fuel cell system includes: a fuel cell; a reaction gas supplier which supplies a fuel gas and an oxidizing gas to the fuel cell; a first converter which converts the output voltage of the fuel cell; a secondary battery; a connection line connecting the first converter and the secondary battery in parallel to a load; and a controller. The controller includes a first operation mode and a second operation mode. In the first operation mode, the first converter is operated with a step-up capability that is able to be realized by the first converter. In the second operation mode, the first converter is operated with the maximum step-up capability that is able to be realized by the first converter and in which the reaction gas supplier is used to control the output current of the fuel cell.

A method for accurately measuring the impedance of the fuel cell stack in the vehicle during operation of the vehicle includes determining whether measuring the impedance of the fuel cell stack is requested during driving of the vehicle driven by using a power of a fuel cell stack, switching a DC-DC converter connecting the fuel cell stack and a battery to each other to a buck mode when measuring the impedance is requested, thereby blocking output current of the fuel cell stack from flowing to the battery through the DC-DC converter, determining a first current value of the fuel cell stack for measuring the impedance, controlling a resistance value of a COD variable resistor consuming the output current of the fuel cell stack according to the first current value, and measuring the impedance of the fuel cell stack while the output current of the fuel cell stack is maintained at the first current value.

A method of operating a fuel cell stack is described. The fuel cell stack includes a cathode, an anode, a sump configured for collecting water from the anode, and a temporarily disabled drain valve that is otherwise configured to transition from a first position to a second position and thereby modulate water drained from the sump. The method includes increasing a first pressure in the anode via a controller. The method also includes, concurrent to increasing, decreasing a second pressure in the cathode via the controller and, concurrent to decreasing, maintaining a relative humidity of less than a threshold relative humidity in the cathode via the controller.