A fuel cell device is provided, including a media system for supplying fluid media to electrochemical units of the fuel cell device and/or for discharging fluid media from the electrochemical units of the fuel cell device, wherein the media system includes at least one valve to which, in a standard operating state of the fuel cell device, an electrical standard input power is suppliable in order to maintain the valve in a desired valve state. The fuel cell device is able to be reliably started with as little effort as possible, even under frost conditions. The fuel cell device is switchable into a heating operating state in which an electrical heating input power that is greater than the electrical standard input power is suppliable to the at least one valve.

A test cell configured to qualify an apparatus for characterizing cells of at least one fuel cell and a method for producing such a test cell. The test cell includes a first and a second contact face respectively including a first and a second contact area entirely or partially occupying a surface of the corresponding contact face, the first and second contact faces together delimiting an interior volume. The test cell further includes an equivalent passive circuit configured to have an equivalent impedance to at least one cell of a fuel cell, the equivalent circuit including a first and a second output terminal respectively connected to the first and second contact areas, the equivalent circuit being housed in the interior volume.

A fuel cell system includes a plurality of electrical components that are supplied with electric power generated by a fuel cell, a refrigerant circuit that cools the fuel cell using a refrigerant, a tank that is connected to the refrigerant circuit, stores the refrigerant, and is replenished with the refrigerant, a detecting unit that detects an insulation resistance value of the fuel cell system, and an identification unit that identifies at what position of the fuel cell system the insulation resistance value has decreased when it is detected that the insulation resistance value has decreased. The detecting unit performs a process of determining whether the decrease in insulation resistance value is temporary when the identified position is the fuel cell and determines that there is no failure requiring repair when the decrease in insulation resistance value is temporary.

A fuel cell system includes a fuel cell, an anode gas supply system, an anode gas circulatory system, a cathode gas supply-discharge system, a gas-liquid discharge passage, a gas-liquid discharge valve configured to open and close the gas-liquid discharge passage, a flow-rate acquisition portion, and a controlling portion. After the controlling portion instructs the gas-liquid discharge valve to be opened, the controlling portion executes a normal-abnormality determination such that, when a discharge-gas flow rate of anode gas is a predetermined normal reference value or more, the controlling portion determines that the gas-liquid discharge valve is opened normally, and when the discharge-gas flow rate is lower than the normal reference value, the controlling portion determines that the gas-liquid discharge valve is not opened normally.

There is provided a fuel cell system. When receiving an instruction to start power generation of the fuel cell system, the fuel cell system is configured: (i) to obtain an output limit value of a secondary battery according to a predetermined relationship of a temperature of the secondary battery to the output limit value of the secondary battery by using the temperature of the secondary battery; (ii) to control a battery converter such as to increase a voltage of a smoothing capacitor for boosting included in the battery converter to a start-time target voltage that is higher than an open circuit voltage of a fuel cell, such that an output power of the secondary battery does not exceed the output limit value; and (iii) to operate the compressor such as to start supplying the cathode gas by the cathode gas supply system and to open the main stop valve such as to start supplying the anode gas by the anode gas supply system.

A method conditions a fuel cell stack of a fuel cell system during a usage operation of the fuel cell system. The method determines that a conditioning of the fuel cell stack is to be carried out for increasing an electrical power provided by the fuel cell stack during usage operation. In addition, the method adjusts at least one operating parameter of the fuel cell system in order to increase a current flow through the fuel cell stack for conditioning the fuel cell stack during usage operation.

A method for addressing electrical grid frequency changes by a fuel cell system includes measuring, by a frequency sensor, a frequency of an electrical grid, determining that the frequency of the electrical grid differs from a normal frequency of the electrical grid by a threshold, determining, based at least in part on the measured frequency, an AC power setpoint bias, applying a magnitude limit, a rate-of-change limit, and a duration limit to the determined AC power setpoint bias to generate a limited power setpoint bias, generating a frequency adjusted power setpoint based on the limited power setpoint bias, and providing the frequency adjusted power setpoint to one or more control modules of the fuel cell system such that the fuel cell system adjusts a power output based on a difference between the measured frequency and the normal frequency.

Systems and methods for facilitating a medium voltage microgrid operation to manage critical loads are disclosed. The system includes at least two fuel cell systems that operate in one of at least two operating modes including a grid-forming mode and a grid-following mode, based on an operation of at least two utility feeders of a grid. The system includes a controller that receives values corresponding to electrical parameter(s) from at least two utility circuit breakers and a load circuit breaker, detects availability status of the utility circuit breakers to supply power to corresponding at least two portions of the critical load, and a connection status of the load circuit breaker, based on the values, and facilitates the at least two fuel cell systems to operate in one of the at least two operating modes. Further, the system is scalable, redundant, and reliable, and reliability and redundancy are customizable.

A fuel cell vehicle includes a fuel cell stack, which is connected to an in-vehicle electric load, a power storage device, which is connected to the fuel cell stack so as to be connected in parallel to the in-vehicle electric load, a state-of-charge sensor, which detects a state of charge of the power storage device, and circuitry that controls the power generated by the fuel cell stack based on the detected state of charge of the power storage device. The in-vehicle electric load includes a driving motor, which is driven based on operation of an operating member. When the state of charge of the power storage device detected by the state-of-charge sensor falls to or below a threshold value, the circuitry executes a restriction process to apply restriction on driving of the driving motor.

A method for operating a fuel cell power plant is provided to deliver power and/or receive power from a load. The fuel cell power plant includes an energy storage system connected in parallel with a fuel cell system. The method for operating includes the steps of calculating and actively proportioning a current split between the fuel cell system and the energy storage system, and controlling the proportioning using fuel cell system air flow. In one embodiment, set point changes in the fuel cell system air flow are operationally independent from a fuel cell water management system that removes product water, humidifies inlet reactant gas, and/or cools the fuel cell stack. In another embodiment, the step of calculating the current split proportion includes the selection of points on a family of V/I curves within a range from 40% fuel cell air utilization to 99% fuel cell air utilization.