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.

An illustrative example fuel cell power plant includes a cell stack assembly, a single stage convertor configured to couple the cell stack assembly to a power network, and a controller that is configured to determine whether the fuel cell power plant has a DC voltage brownout condition during an islanded mode of operation. The controller dynamically adjusts the frequency droop gain of the power plant using an offset while satisfying at least three criteria of a set of criteria consisting of (i) avoiding overloading other fuel cell power plants of the power network, (ii) avoiding exceeding a maximum load step-up capability of the power network, (iii) avoiding exceeding a maximum load step-up capability of the fuel cell power plant, (iv) maintaining a system frequency within an acceptable frequency range, and (v) avoiding repeating the DC voltage brownout condition.

A method for operating a fuel cell system comprising a fuel cell assembly of a plurality of fuel cells configured to generate electrical power from a fuel flow and an oxidant flow to the plurality of fuel cells, the fuel cell assembly arranged in combination with a coolant storage module configured to supply the fuel cell assembly with a flow of coolant, the method performed when the temperature of the coolant in the coolant storage module is below a coolant temperature threshold and comprises; a first phase performed prior to activation of a coolant pump configured to deliver coolant from the coolant storage module to the fuel cell assembly and a second phase performed after activation of the coolant pump.

A fuel cell system includes a fuel cell, a supply device configured to supply a cathode gas to the fuel cell; and a control unit configured to execute recovery processing of causing a catalyst of the fuel cell to recover from performance deterioration by lowering an output voltage of the fuel cell. The control unit is configured to, when the recovery processing that has been executed is completed, control the supply device to place the fuel cell in a power generation paused state while making a stoichiometric ratio of the cathode gas lower than a stoichiometric ratio of the cathode gas in a normal operation state that is a state before execution of the recovery processing.

A stack fuel cell array featuring paired fuel-cell systems combined to generate 540 VDC for a rotorcraft. Power from the hydrogen-based fuel cells is provided to the rotorcraft. A rated electrical load of the rotorcraft helps determine how many paired fuel-cell systems are needed during any fuel-cell systems failures. Each of the paired fuel-cell systems is coupled to an electrical load of the rotorcraft. The system detects any fuel cell failures and removes other working fuel cells as needed to balance the electrical system.

To provide a fuel cell system including: a fuel cell group including a plurality of fuel cells; a refrigerant distribution passage through which a refrigerant is individually distributed to the fuel cells composing the fuel cell group; a pre-distribution refrigerant flow rate acquiring unit configured to acquire a first outlet temperature flow rate that is a flow rate of the refrigerant before distribution; a first outlet temperature detecting unit that is provided at a refrigerant outlet of at least one first fuel cell in the fuel cell group in the refrigerant distribution passage, and is configured to detect a first outlet temperature that is a refrigerant outlet temperature of the first fuel cell; a voltage acquiring unit configured to acquire at least a first voltage that is a voltage of the first fuel cell; a current acquiring unit configured to acquire at least a first current that is a current of the first fuel cell; and a controller that calculates a first individual supply flow rate of the first fuel cell on the basis of the first voltage, the first current, and the first outlet temperature, and calculates a second individual supply flow rate of at least one second fuel cell other than the first fuel cell on the basis of the first individual supply flow rate and the pre-distribution refrigerant flow rate.

A fuel cell system includes a fuel cell module, auxiliary equipment, a power converter, and a casing containing the fuel cell module, the auxiliary equipment, and the power converter. The casing has a plurality of surfaces including one detachable maintenance surface. Only the maintenance surface has an air intake port for taking an oxygen-containing gas into the casing, an air exhaust port for discharging an exhaust gas discharged from the fuel cell module, to the outside of the casing, and a ventilation inlet port and a ventilation outlet port for ventilation of an inside of the casing by air.

An electrical system includes a stack (3) of electrochemical cells (5), a power converter (9) electrically connected to the stack (3), a voltage comparator (7) for comparing the voltage at the terminals of at least one group of at least one electrochemical cell (5) of the stack (3) to a threshold voltage, and a control module (11) for controlling the converter (9). The control module (11) includes a generator (74) for generating a control instruction for controlling the converter (9) and a transmission member (76) for transmitting the control instruction to the converter (9). The voltage comparator (7) is suitable for transmitting a signal to the transmission member (76). The signal consists of a first instruction from an instruction for transmitting and an instruction for blocking the control instruction when the compared voltage is higher than the threshold voltage, and a second instruction from the instructions for transmitting and blocking the control instruction when the compared voltage is lower than or equal to the threshold voltage.

A high-temperature operation fuel cell system includes a cell stack; a reformer; a raw material supplier supplying a raw material to the reformer; a water supplier supplying reforming water; an air supplier supplying electric power generation air; a combustion chamber in which an off-gas from the cell stack is combusted and which heats the cell stack and the reformer; an igniter igniting the off-gas in the combustion chamber; and a controller. In a start-up sequence, the controller controls so that the raw material is supplied to the reformer, the electric power generation air is supplied to the cell stack, the off-gas is ignited by the igniter, and after the ignition, the supply of the reforming water is started, and after the supply of the reforming water is started, the controller further controls the air supplier to increase the flow rate of the electric power generation air in a stepwise manner.

Device and method for controlling fuel cell stack connection. The device includes fuel cell stacks and a power conditioning unit connected to the stacks, and further includes: a memory storing a first critical value by which the connection control device starts an operation, second critical values ranging from zero to the first critical value, and a boundary value for placing the second critical values in at least two subsidiary ranges; stack voltage sensing units for sensing voltages of the stacks; and a control unit for determining whether sensed voltages have been reduced to the first critical value or greater, and starting to control the operation of a switching unit when any one of the sensed voltages has been reduced to the first critical value or greater, thereby placing one or more stacks having voltages associated with each one of the at least two subsidiary ranges in one of individual groups.