A fuel cell system comprises a controller configured to determine whether a condition relating to a stop pattern of the fuel cell system satisfies a predetermined condition, and an output unit configured to output a warning when it is determined that the condition relating to the stop pattern satisfies the predetermined condition.

An illustrative example method of controlling operation of a fuel cell power plant includes opening a pneumatic valve using pneumatic pressure of pressurized fuel cell reactant, allowing the pressurized fuel cell reactant to flow through the pneumatic valve to a cell stack assembly, determining that shutdown of the cell stack assembly is desired, and control a rate that the pneumatic valve closes by controlling a rate of release of the pneumatic pressure.

Systems and methods for operating an electric energy storage device are described. The systems and methods may generate a state of charge estimate that is based on negative electrode plating. An overall state of charge may be determined from the state of charge estimate that is based on negative electrode plating and a state of charge estimate that is not based on negative electrode plating.

Systems and methods for operating an electric energy storage device are described. The systems and methods may generate a state of charge estimate that is based on negative electrode plating. An overall state of charge may be determined from the state of charge estimate that is based on negative electrode plating and a state of charge estimate that is not based on negative electrode plating.

The invention relates to a method for fueling fuel cell systems (Sys A, Sys B) which are operated in an assembly (10) of a plurality of fuel cell systems (Sys A, Sys B), and to a fuel cell system assembly (10). According to the invention, a method is provided by means of which a load (100) operated by the assembly (10) can continue to be operated while a fueling process is carried out by a fueling device 20 assigned to the fuel cells (FC 1, FC 2) of the fuel cell system (Sys A, Sys B).

A method for distinguishing the cause of voltage losses in a fuel cell device includes: a) Detection of a quasi-stationary operation of the fuel cell device, b) Acquisition and storage of a measured current-voltage characteristic curve with the current values and the voltage values of a fuel cells stack of the fuel cell device, c) Use of a PtOx model to determine PtOx voltage losses and calculation of a corrected current-voltage characteristic curve for the PtOx-free and normally humidified fuel cell stack, and d) Comparison of the current-voltage characteristic curves determined in step b) and in step c) and detection of an at least partially dried-out fuel cell stack if the measured current-voltage characteristic curve runs below the corrected current-voltage characteristic curve. A fuel cell device and a motor vehicle comprising a fuel cell device are also provided.

System, methods, and other embodiments described herein relate to safely ceasing fuel cell (FC) operation and idling components of a generator. In one embodiment, a method includes ceasing power generation by reducing fuel to an FC within a generator while maintaining energy to sensitive components by a battery. The method also includes idling a direct current (DC) converter and a load inverter associated with the power generation before idling the battery. The method also includes, upon successfully completing tests and powering down non-critical components of the generator, entering the generator into a standby status.

A safety management system for an aircraft, or a propulsion system thereof including a fuel cell assembly and a combustion engine, may include various sensors and controllers configured to execute a safety action. At least one sensor is configured to detect at least one operating parameter of the propulsion system, and a controller is configured to determine that the at least one operating parameter has achieved a safety threshold and to execute a safety action when the at least one operating parameter has achieved the safety threshold. The safety action is configured to control operation of the fuel cell assembly and to control operation of the combustion engine.

A safety management system for an aircraft, or a propulsion system thereof including a fuel cell assembly and a combustion engine, may include various sensors and controllers configured to execute a safety action. At least one sensor is configured to detect at least one operating parameter of the propulsion system, and a controller is configured to determine that the at least one operating parameter has achieved a safety threshold and to execute a safety action when the at least one operating parameter has achieved the safety threshold. The safety action is configured to control operation of the fuel cell assembly and to control operation of the combustion engine.

A fuel cell system includes: a fuel cell; a first valve device provided at an oxidation gas supply channel; a second valve device provided at an oxidation off-gas discharge channel; a third valve device provided at a bypass channel; an abnormality detection unit configured to detect an abnormality; and a control unit. The control unit causes the fuel cell to initiate fail-safe power generation if (i) a different abnormality from a valve opening abnormality is detected in the first valve device, (ii) the different abnormality is detected in the second valve device, or (iii) any abnormality is detected in the third valve device. During the fail-safe power generation, if any abnormality is additionally detected in any valve device different from the valve device in which an abnormality is already detected, the control unit stops power generation by the fuel cell.