A system and method for controlling a start of a fuel cell vehicle are provided. The method includes supplying hydrogen and air to a fuel cell and operating a converter so that a voltage on a high-voltage bus is constant, wherein the converter is disposed between a high-voltage battery and the high-voltage bus which is connected to an output terminal of the fuel cell. The voltage on the high-voltage bus is maintained at a preset lowest control voltage and the voltage on the high-voltage bus is adjusted based on a result comparing a preset lower-limit operational voltage of an inverter with an inverter detection voltage. The inverter is disposed between the high-voltage bus and a drive motor, and the inverter detection voltage is detected on a terminal of the inverter which is connected to the high-voltage bus.

A fuel cell stack hydrogen starvation detection device, a fuel cell system and a method of operating a fuel cell stack to protect it from hydrogen starvation conditions. In one particular form, the fuel cell system includes a stack of fuel cells, a controller and a detection device made up of one or more sensors that can compare a reference signal corresponding to the presence of substantially pure hydrogen to a signal that corresponds to a local hydrogen value within a single fuel cell within the stack or across multiple fuel cells within the stack. In this way, the detection device promptly provides indicia of a hydrogen starvation condition within the cell or stack without the need for conventional cell voltage monitoring. The detected hydrogen starvation condition may be presented as a warning signal to alert a user that such a condition may be present, as well as to the controller for modification of the stack operation.

In a method of activating a fuel cell, after a voltage application step is performed, a humidifying step is performed. In the voltage application step, a hydrogen gas is supplied to an anode, and an inert gas is supplied to a cathode. In the meanwhile, cyclic voltage which is increased and decreased within a predetermined range is applied to the fuel cell. In the humidifying step, in a state where application of the voltage is stopped, a humidified gas containing water vapor is supplied to at least one of the anode and the cathode.

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 fuel cell system comprising: a power generation controller that controls a value subject to control, which is a value exhibiting a power generating state by a fuel cell and is a value that is affected by alternating current applied to the fuel cell, to approach a target value; a dead zone setter that sets a dead zone with the target value as a reference; and, a stopper that stops the control by the power generation controller when the value subject to control is contained in the dead zone.

A shut down system of a fuel cell vehicle includes: a fuel cell configured to output a high voltage; a rechargeable high voltage battery; a bidirectional converter arranged between an output terminal of the fuel cell and the high voltage battery; a first relay arranged between the fuel cell and the bidirectional converter; and a controller configured to control a voltage of the bidirectional converter when the fuel cell vehicle stalls to reduce a voltage of the output terminal of the fuel cell and turn off the first relay when a voltage value of the output terminal of the fuel cell is below a preset voltage reference value.

An electrochemical cell system and a method for operating an electrochemical cell is provided. The method including determining one of a power level, current level or a voltage level of the electrochemical cell, the electrochemical cell including at least one cell having an anode side and a cathode side, the electrochemical cell further having a water transport plate operably coupled to the cathode side. An oxidant pressure level is determined in the cathode side. A water pressure level is determined in the water transport plate. The active area of the at least one cell is changed by adjusting at least one of the oxidant pressure level or the water pressure level based at least in part on the determined power level, current level or voltage level.

An electrochemical cell system and a method for operating an electrochemical cell is provided. The method including determining one of a power level, current level or a voltage level of the electrochemical cell, the electrochemical cell including at least one cell having an anode side and a cathode side, the electrochemical cell further having a water transport plate operably coupled to the cathode side. An oxidant pressure level is determined in the cathode side. A water pressure level is determined in the water transport plate. The active area of the at least one cell is changed by adjusting at least one of the oxidant pressure level or the water pressure level based at least in part on the determined power level, current level or voltage level.

A drive system includes a drive device including an electric power generator; a fuel cell; a secondary battery; a fuel cell step-up converter including a diode; a relay connected to wiring between the fuel cell step-up converter and the drive device; a secondary battery step-up converter connected; a fuel cell voltage sensor; a secondary battery voltage sensor; and a controller. The controller stops the secondary battery step-up converter when a short-circuit fault of the diode is detected, disconnects the relay when a voltage of the fuel cell is higher than a voltage of the secondary battery after stopping the secondary battery step-up converter, and when the voltage of the secondary battery is higher than or equal to the voltage of the fuel cell, executes a voltage control process which increases the voltage of the fuel cell relative to the voltage of the secondary battery, and disconnects the relay.

A method for starting the normal operation of an electrical system with a fuel cell and a transducer from a stop mode is disclosed. The transducer absorbs the electrical power of the fuel cell, in which at least one reactant supply of the fuel cell was interrupted, where the interrupted reactant supply is resumed from a restart signal, and where a fuel cell voltage is prescribed and then regulated by the transducer. The prescribed fuel cell voltage is prescribed in a way that an electrical unloaded fuel cell supplied with reactants will exceed the prescribed fuel cell voltage in every case, and the current of the transducer necessary for maintaining the prescribed fuel cell voltage is measured, where the normal operation is released as of a prescribed current necessary to that effect.