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.

A method for diagnosing an operating status of a fuel cell system having a fuel cell and a system for operating media management, includes creating an operating model (M) of the fuel cell, including an electrochemical model (ecM) and a physical model (pM) coupled thereto. By the electrochemical model (ecM), an electrical operating power (P) of the fuel cell is determinable as a function of an electrical operating current (J) and thermodynamic operating parameters (). By the physical model (pM), a time-dependent spatial distribution of the thermodynamic operating parameters () is determinable. The method further includes: detecting the electrical operating current (J) of the fuel cell and status variables () of operating media of the fuel cell; and determining the electrical operating power of the fuel cell by the operating model (M) based on the detected electrical operating current (J) and the detected status variables () of the operating media.

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 fuel cell system includes: a processing unit configured to perform an activation process of temporarily reducing a cathode potential of a single fuel cell to a target potential for a duration time at a processing frequency; a cationic impurity amount estimating unit configured to estimate an amount of cationic impurities included in an electrolyte membrane of the single fuel cell; and a process degree determining unit configured to determine, when the amount of cationic impurities is large, a degree of the activation process which is higher than that determined when the amount of cationic impurities is small by performing at least one action among actions of changing conditions of the activation process, the actions including an action of reducing the target potential, an action of increasing the duration time, and an action of increasing the processing frequency. The processing unit performs the activation process to the determined degree.

An AC component I addition unit of a diagnostic device superimposes an alternating current on an output current of a fuel cell. A Zn calculation unit calculates a cell impedance with respect to the alternating current with regard to any of a plurality of cells. A diagnosis unit diagnoses that any cell is subjected to hydrogen deficiency when an absolute value of the cell impedance exceeds (absolute value of a reference impedance+a predetermined value ). It is diagnosed that any cell is subjected to oxygen deficiency when the absolute value of the cell impedance is smaller than (absolute value of the reference impedancea predetermined value ).

The present disclosure is directed to a fuel cell system for generating oxygen depleted air. The fuel cell system may include a fuel cell having an anode, a cathode, and an electrolyte positioned between the anode and the cathode. The cathode may be configured to receive an air flow and discharge an oxygen depleted air flow. The fuel cell system may further include a sensor configured to generate a first signal indicative of a presence of hydrogen in the oxygen depleted air flow and a controller in communication with the sensor and the fuel cell. The controller may be configured to detect the presence of hydrogen in the oxygen depleted air flow based on the first signal, and in response to detecting the presence of hydrogen in the oxygen depleted air flow, selectively cause a current density of the fuel cell to decrease and/or increase a flow rate of the air flow to the cathode.

In one embodiment, there is provided a fuel cell evaluator for evaluating a characteristic of a fuel cell based on a frequency characteristic of impedance of the fuel cell. The evaluator includes: an impedance acquisition unit configured to acquire impedances of the fuel cell for a certain current value in a Tafel region by changing a measurement frequency; an extraction unit configured to extract a reaction resistance from the acquired impedances; a calculator configured to calculate the product of the reaction resistance and the certain current value; and an indicator configured to indicate the product calculated by the calculator as the frequency characteristic of the impedance of the fuel cell.

Disclosed is a method of controlling the operation of a fuel cell triple cogeneration system configured to supply power and cooling heat to a data center, the method including detecting change in a power load or a cooling heat load of the data center and adjusting electrical energy and cooling capacity of the fuel cell triple cogeneration system.

To provide a hydrogen consumption system capable of suppressing the generation of emission sound at the time of separation of a hydrogen tank, which is unlikely to cause defects. Detachable hydrogen tank, a fuel cell using hydrogen from the hydrogen tank as a fuel, connecting the hydrogen tank and the fuel cell, a pipe through which hydrogen flows, the opening and closing valve provided in the pipe, and a control device, when desorption of the hydrogen tank, the control device closes the on-off valve, the pressure in the pipe to calculate the amount of hydrogen consumed by the power generation of the fuel cell until less than 1 MPa, the current demand value of the fuel cell from the amount of hydrogen consumed, and, the current upper limit value of the fuel cell is calculated, when the actual current value is greater than the current upper limit value, the current request value performs control for changing to be equal to or less than the current upper limit value.

A method and a system for optimizing a lifetime of a fuel cell system based on adjustment and constraint of a thermoelectric ratio are provided. The method includes obtaining initial reference voltages of a plurality of single-machine fuel cell systems, and performing a durability test under a normal operating condition to obtain variation relationships of reference voltage over time; monitoring an operating voltage of each of the single-machine fuel cell systems in real-time under the normal operating condition to obtain a real-time monitored voltage and a real-time voltage deviation; calculating a performance expected attenuation profile of each of the single-machine fuel cell systems under the normal operating condition; obtaining current density distribution and actual available heat of each of the single-machine fuel cell systems, and calculating a health state boundary of each of the single-machine fuel cell systems in stable operation, so as to optimize operating modes of the systems.