A fuel cell system having a fuel cell operated under non-humidified conditions that includes a polymer electrolyte membrane sandwiched between an anode and a cathode, a fuel gas channel facing the anode to supply it with fuel gas, an oxidant gas channel facing the cathode to supply it with oxidant gas, and a flow direction of the fuel gas and the oxidant gas are opposite. The fuel cell system may control a water vapor amount at an outlet of the fuel gas channel based on a value that is set based on a relationship between a voltage of the fuel cell and the water vapor amount. The fuel cell system may control an average flow rate of the fuel gas in the fuel gas channel based on a value that is set based on a relationship between a voltage of the fuel cell and the average flow rate.

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 flow battery includes at least one cell that has a first electrode, a second electrode spaced apart from the first electrode and an electrolyte separator layer that is arranged between the first electrode and the second electrode. A storage portion is fluidly connected with the at least one cell. At least one liquid electrolyte includes an electrochemically active specie and is selectively deliverable to the at least one cell. An electric circuit is coupled with the first electrode and the second electrode. The circuit includes a voltage-limiting device that is configured to limit a voltage potential across the first electrode and the second electrode in response to a transition of the at least one cell from an inactive, shut-down mode with respect to an active, charge/discharge mode.

There are provided: a solid polymer power generation or electrolysis method that does not require injection of energy from the outside and maintenance of a high temperature, and is capable of converting carbon dioxide to a useful hydrocarbon while producing energy, controlling the production amounts of the hydrocarbons or the like and a ratio sorted by kind of the hydrocarbons, improving utilization efficiency of a product, and simplifying equipment for separation and recovery; and a system for implementing the solid polymer power generation or electrolysis method. Carbon dioxide is supplied to the side of one electrode 111 of a reactor 110 having a membrane electrode assembly 113, hydrogen is supplied to the side of the other electrode 112, and the amounts of the hydrocarbons produced per unit time and the ratio sorted by kind of the hydrocarbons are changed by controlling a power generation voltage of the reactor 110.

Disclosed are a fuel cell system and a method for controlling the same which enable performance recovery of a stack together with a high potential avoidance operation while operating the fuel cell system. The fuel cell system includes a fuel cell stack, in which a first separation plate having a first air flow path and a second separation plate having a second, different air flow path are alternately stacked with a membrane-electrode assembly interposed therebetween; and the method includes determining whether a high-potential avoidance operation is required while operating the fuel cell system including the fuel cell stack, and selectively supplying air to the air flow path of the first separation plate or the second separation plate when a high-potential avoidance operation is required, so as to easily achieve cathode performance recovery during the high-potential avoidance operation of the fuel cell system and the operation of the fuel cell system.

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.

A fuel cell charging system includes a fuel cell stack having a first operating direct current (DC) voltage between fuel check stack terminals, a high voltage system operating at a first DC operating voltage different than and generally higher than the first operating voltage of the fuel cell stack, a boost converter in electrical connection with the fuel cell stack and the high voltage system, and a stack charging component that applies a second DC operating voltage, generally of lower value than that of the first normal operating voltage, to the fuel cell stack. The boost converter transfer electrical power from the fuel cell stack to the high voltage system during fuel cell operation. Characteristically, the second DC operating voltage applied to the fuel cell stack terminals is typically lower in value than that of the first DC operating voltage of both the fuel cell stack and the HV electrical system and is stepped down from the first DC operating voltage of the HV electrical system.

A restarting system, a controller, and a restarting method for a fuel cell vehicle are provided. The restarting system includes a consumption resistor connected in parallel to a high voltage line that connects between a fuel cell and a high voltage battery and a relay that adjusts the connection between the consumption resistor and the high voltage line. A controller operates the relay and when a shutdown request signal of the vehicle is input, charges the high voltage battery with residual generated power of the fuel cell or connects the relay to the consumption resistor to consume the residual generated power as the consumption resistance. When a starting request signal of the vehicle is input, the controller is reset when an output voltage of the fuel cell is reduced to be equal to or less than a required voltage and then output a starting permission signal of the vehicle.

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 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.