The present invention enables the determination of an operating point of a fuel cell so as to prioritize the fulfillment of an amount of required power generation while avoiding various limitations, such as a current limit, in a fuel cell system that warms up the fuel cell by a low efficiency operation. A controller 70 multiplies a voltage command value V.sub.com obtained in step S3 by a current command value I.sub.com obtained in step S1, then, this is divided by a final voltage command value V.sub.fcom obtained in step S4, thereby obtaining a final current command value I.sub.fcom to determine an operating point (I.sub.fcom, V.sub.fcom) during a warm-up operation (step S5), and then the process ends.

A control device for a fuel cell system comprises a hydrogen deficiency judging part configured to judge if a hydrogen deficiency which is a state in which an amount of hydrogen supplied to the fuel cell is insufficient compared with an amount of hydrogen required for power generation has occurred, a hydrogen deficiency elimination judging part configured to judge if the hydrogen deficiency has been eliminated after the hydrogen deficiency judging part judges that the hydrogen deficiency has occurred and a breakage control part configured to make the circuit breaker temporarily break an electrical connection of the fuel cell and the electrical load part when the hydrogen deficiency elimination judging part judges that the hydrogen deficiency has been eliminated.

A method of cleaning power cells in an array of power cells, comprising coupling at least one first power cell to second power cells in an array of power cells and causing the second power cells to drive the at least one first power cell with a voltage to clean catalyst on the at least one first power cell.

In a fuel cell system including a fuel cell, an anode gas supply channel, an anode gas discharge channel, an injector, a pressure sensor, and a controller, the controller controls the injector so that the pressure on the downstream side of the injector in the anode gas supply channel and does not become lower than target pressure, closes a discharge valve when the amount of discharged anode gas reaches a target discharge amount, the amount of discharged anode gas estimated based on the amount of decrease in the value of the pressure in a first period of the discharge valve open-period, the first period being a period from the point of time after the injector stops the injection and when variation of the pressure falls within a predetermined range to the point of time when the injector next starts the injection, and increases a ratio of the first period to the drive cycle by controlling, during the discharge valve open-period, at least one of the anode gas supply rate of the injector, the amount of electric power generated by the fuel cell, and the drive cycle of the injector.

Disclosed are a redox flow battery and a method of measuring a state of charge (SOC) thereof. The method may include measuring an open circuit voltage (OCV) during a specific period of time when a charging or discharging operation of a redox flow battery is performed, analyzing a change in SOC of the redox flow battery based on the measured OCV, correcting Coulomb efficiency based on the change in SOC, and calculating a second SOC of the redox flow battery based on the corrected Coulomb efficiency. The Coulomb efficiency may be a parameter, in which information regarding actual operation factors of the redox flow battery is contained.

A fuel cell system comprising: an acquirer that acquires a total value of cell voltages of two or more cells included in a fuel cell; and a determiner that determines, when the total value is a first voltage value, abnormal power generation in which power generation by at least a part of the two or more cells is abnormal, that determines, when the total value is a second voltage value higher than the first voltage value, normal power generation in which power generation by the two or more cells is normal and that determines, when the total value is a third voltage value higher than the first voltage value but lower than the second voltage value, the normal power generation if a cathode gas is deficient or the abnormal power generation if the cathode gas is not deficient.

A fuel cell system incorporated in a vehicle includes a fuel cell that uses a reaction gas to generate electric power and a controller. When output restriction that restricts the electric power output by the fuel cell is performed, (a) the controller does not store a content of the performed output restriction as a history in a case where a throttle opening of a throttle is smaller than an opening threshold or an output request is smaller than an output threshold, the output request being issued to the fuel cell and set in accordance with the throttle opening, and (b) the controller stores the content of the performed output restriction as a history in a case where a condition specified in advance is satisfied while the throttle opening is greater than the opening threshold and the output request is greater than the output threshold.

A fuel cell assembly according to an exemplary aspect of the present disclosure includes, among other things, a first fuel cell stack in series with a variable resistor and a second fuel cell stack in parallel with the first fuel cell stack and in series with a contactor. A resistance level of the variable resistor is adjusted in response to deactivating the contactor.

A control method for a fuel cell system with a gas supplying device configured to supply fuel gas and oxidant gas to a fuel cell, includes a power generating operation step of performing a power generating operation for causing the fuel cell to generate power by controlling the fuel gas and the oxidant gas to be supplied to the fuel cell on the basis of a load required of the fuel cell. Further, the control method includes an autonomous operation step of performing an autonomous operation of the fuel cell when the load drops to or below a predetermined value. In the autonomous operation, power supply from the fuel cell system to the load is stopped and the fuel gas is passed to an anode of the fuel cell.

A fuel cell system supplies a fuel and an oxidant and outputs a generated power from the fuel cell to a secondary battery. In a method for controlling the fuel cell system, a charged amount of the secondary battery is acquired, when the charged amount of the secondary battery becomes equal to or less than a prescribed value, the fuel cell is started up from a state that the fuel cell stops power generation, or the generated power of the fuel cell is increased. In the method for controlling, a remaining amount of the fuel which can be supplied to the fuel cell is acquired and when the remaining amount of the fuel becomes small, the prescribed value is set to a smaller value as compared with when the remaining amount of the fuel is large.