A method for repairing a fuel cell stack having a plurality of individual cells involves the steps of: a) identifying at least one degraded individual cell in the fuel cell stack; and b) deactivating the at least one degraded individual cell.

Proposed is a fuel cell power control system. A fuel cell generates electric power. A load unit is electrically connected to the fuel cell. A DC/DC converter is disposed between the fuel cell and the load unit to convert the electric power between a low side of the DC/DC converter electrically connected to the fuel cell and a high side of the DC/DC converter electrically connected to the load unit. A battery is electrically connected to the high side of the DC/DC converter to be parallel to the load unit. A controller monitors a voltage of the load unit, the battery, or the high side of the DC/DC converter, and controls the electric power input to the load unit or output from the load unit in accordance with the monitored voltage.

A fuel-cell system for powering an electrical load, the system having first and second fuel cells, each having a positive node and a negative node. The positive node of the second fuel cell is electrically coupled to the negative node of the first fuel cell, and the positive node of the first fuel cell and the negative node of the second fuel cell are electrically coupled to the electrical load. Each fuel cell is electrically coupled to the electrical load without a power converter.

A power generation control system of a fuel cell includes: the fuel cell generating a power through a chemical reaction between fuel and air; a consuming device connected to an output terminal of the fuel cell and consuming the power output from the fuel cell; a converter connected between the fuel cell and the consuming device in series or parallel and adjusting an output voltage of the fuel cell; a supply device supplying the air to the fuel cell; a voltage controller controlling the converter on the basis of a required power or current of the fuel cell required to be output; and a supply controller controlling the supply device on the basis of the required power or current of the fuel cell required to be output.

A power conditioning system that includes a fuel cell to be connected to a load, a fuel cell converter connected between the fuel cell and the load, the fuel cell converter converting an output voltage of the fuel cell at a predetermined required voltage ratio, a battery connected in parallel with the fuel cell with respect to the load, the battery serving as a power supply source different from the fuel cell, a battery converter connected between the battery and the load, the battery converter converting an output voltage of the battery at a predetermined required voltage ratio. The power conditioning system includes a converter direct coupling unit configured to directly couple an input side and an output side of the fuel cell converter during startup of the power conditioning system and a fuel cell output voltage increasing unit configured to increase the output voltage of the fuel cell to a predetermined voltage by supplying oxidant gas during startup of the fuel cell.

A power supply unit includes a power supply and a converter. The converter performs operation selected from the group consisting of boosting and stepping down of an output voltage of the power supply; and includes a reactor in which n-phase coils are magnetically coupled to each other, n-phase switches, and a control unit. The control unit controls duty cycles of the n-phase switches; monitors a current value flowing through the n-phase coils; and performs phase switching control when the control unit determines that an operation condition described below is satisfied, the phase switching control being control in which the control unit performs phase switching from in phase to out of phase in the case where the n-phase switches are being driven in phase and performs phase switching from out of phase to in phase in the case where the n-phase switches are being driven out of phase.

A method of operating a fuel cell assembly comprising a plurality of fuel cells connected together for collectively providing power to a load, each fuel cell including an anode and a cathode, the method comprising selectively providing an electrical connection between the anode and the cathode of at least one of the fuel cells of the assembly for lowering the voltage across the fuel cell independent of the load.

An aircraft includes a chamber (1), a processor, a memory, and a compressor system (12b) in fluid communication with the chamber. The compressor system (12b) configured to selectively pressurize the chamber (1). The chamber supports a fuel cell (26), a motor, and/or electrical components that electrically communicate with the fuel cell (26) and the motor to power the aircraft. The memory includes instructions stored thereon, which when executed by the processor, cause the aircraft to receive an altitude value of the aircraft, and selectively pressurize the chamber using the compressor system based on the received altitude value to reduce corona discharge in the chamber.

A method of controlling energy supply in a fuel cell vehicle includes storing an output current of a fuel cell as a pre-limited current when a cell voltage ratio reaches a minimum cell voltage ratio, setting a limited output current of the fuel cell as the pre-limited current when the cell voltage ratio reaches a hazard cell voltage ratio, connecting first and second high-voltage batteries to a main bus terminal in parallel when the cell voltage ratio reaches the hazard cell voltage ratio, and outputting a supplementary current from the second high-voltage battery by an insufficient amount of the output current of the fuel cell for the pre-limited current, and a system for performing the same.

A process for starting a PEM fuel cell module includes blowing air through the cathode side of the module using external power. An amount hydrogen is released into the anode side of the module under a pressure greater than the pressure of the air on the cathode side, while the anode is otherwise closed. Cell voltages in the module are monitored for the appearance of a charged state sufficient to start the module. When the charged state is observed, the module is converted to a running state.