A fuel cell unit includes a fuel cell and a converter. A fuel cell has single cells laminated in a given direction. A converter has a plurality of combinations of a reactor electrically connected with the fuel cell and a power module electrically connected with the reactor. At least either a direction in which first reactors among the reactors are arrayed or a direction in which first power modules among the power modules are arrayed is parallel with a laminating direction of the single cells.

An apparatus for sensing voltage information of a fuel cell includes: a sensing unit configured to sense voltages of each cell and all cells included in a fuel cell; a controller configured to control the sensing unit to sense the voltages of each cell and all the cells of the fuel cell according to a command of an upper controller, or to transmit information of the sensed voltages of each cell and all the cells to the upper controller; and the upper controller configured to detect an error cell by calculating output power of the fuel cell based on the information of the voltages received from the controller, to substantially prevent damage to a surrounding cell by stopping an operation of the error cell, and to control the output power in real time in correspondence with a state of the fuel cell.

A method of controlling a fuel cell device includes: a step of determining whether impedance between a fuel electrode and an oxidant electrode is greater than a predetermined threshold during a steady operation of the fuel cell device; a step of decreasing a flow rate of a gas circulating via a circulation passage connecting a gas introduction passage of the gas supply unit to a gas discharge passage when the impedance is greater than the predetermined threshold; a step of measuring the voltage between the fuel electrode and the oxidant electrode when the impedance is equal to or less than the predetermined threshold, and determining whether the voltage is equal to or less than a first predetermined threshold; and a step of increasing the flow rate of the gas circulating via the circulation passage when the voltage is equal to or less than the first predetermined threshold.

A power generation system includes a power source that is configured to communicate with at least one of a downstream load or a downstream device by changing a voltage on a power bus between the power source and the at least one of the downstream load or the downstream device, while power source provides power on the power bus to the at least one of the downstream load or the downstream device.

An electronic circuit arrangement for a fuel cell arrangement may include a first electrical voltage converter stage and a second electrical voltage converter stage. An electrical fuel cell voltage may be appliable to the first electrical voltage converter stage on an input side. The electrical fuel cell voltage may be convertible into a first electrical output voltage of the first electrical voltage converter stage via the first electrical voltage converter stage. The first electrical output voltage may be appliable to the second electrical voltage converter stage on an input side. The first electrical output voltage may be convertible into a second electrical output voltage of the second electrical voltage converter stage via the second electrical voltage converter stage. An electrical interconnection of the first electrical voltage converter stage and the second electrical voltage converter stage may be switchable between a first interconnection state and a second interconnection state.

A fuel cell system includes a supply valve for supplying an anode gas into an anode system, a purge valve for discharging an off-gas from the anode system, a pressure detecting portion configured to estimate or measures a pressure inside the anode system, a supply valve control portion configured to control an open/close operation of the supply valve based on a load of the fuel cell, a purge flow rate estimating portion configured to estimate a purge flow rate of the off-gas discharged from the anode system through the purge valve based on a pressure decrease inside the anode system in a supply valve close state, and a purge valve control portion configured to open the purge valve in synchronization with the supply valve close state.

A vehicle system of the present invention includes: a motor configured to drive a vehicle; a high voltage storage device connected to the motor and configured to supply the motor with power; a fuel cell connected to the high voltage storage device and configured to charge the high voltage storage device; and a low voltage storage device connected to the fuel cell. The vehicle system includes: a bidirectional first voltage converter interposed between the fuel cell and the high voltage storage device, and configured to adjust a voltage at either of the fuel cell or the high voltage storage device and to supply power to the other; and a second voltage converter interposed between the fuel cell and the low voltage storage device, and configured to adjust a voltage at the low voltage storage device and to apply the adjusted voltage to the fuel cell. The vehicle system is characterized in that the vehicle system includes a bidirectional third voltage converter interposed between the high voltage storage device and the low voltage storage device, and configured to adjust a voltage at either of the high voltage storage device or the low voltage storage device and to supply power to the other.

A fuel cell system in a vehicle has a cathode and an anode. A compressor has an inlet and an outlet, the outlet being configured to outlet a compressed air from the compressor. A bypass line is configured to return the compressed air from the outlet to the inlet such that the air returns to the compressor in a loop. A valve is located downstream of the compressor and is operable in a plurality of modes. In a first mode, the valve is configured to block the air from the cathode and return the air via the bypass line. In a second mode, the valve is configured to direct at least some of the air to the cathode. The valve can also be configured to operate in a third mode in which the air is sent to the cathode without going through the bypass line.

A voltage is applied between an anode and a cathode in a fuel cell. The voltage is increased to a predetermined upper limit, and then decreased to a predetermined lower limit. The voltage increase and decrease are repeated a predetermined number of times.

A fuel cell system includes a removal treatment execution unit configured to execute an oxide layer removal treatment that removes an oxide layer generated on a catalyst of a fuel cell. The removal treatment execution unit is configured to execute the oxide layer removal treatment by adjusting a voltage of the fuel cell to be within a predetermined second voltage range lower than a predetermined first voltage range that is lower than an open-circuit voltage, when an operation of the fuel cell system shifts from a first operation, where a current value of the fuel cell is zero and the flow rate is controlled to maintain the voltage of the fuel cell within the first voltage range, to a second operation, where the current value is larger than zero and the flow rate is controlled in response to an output request to the fuel cell.