A fuel cell system includes a control unit that detects an abnormality of a flow dividing valve provided in a bypass channel for an oxidation gas by using a detected opening degree detected by a valve opening degree detection sensor that detects the opening degree of the flow dividing valve. When the detected abnormality is an opening abnormality that is failure to open and the flow dividing valve can close, the control unit sends a closing command for making the opening degree smaller than a current opening degree to a valve driving motor. Either when the detected abnormality is a closing abnormality that is failure to close and the flow dividing valve can open or when the detected abnormality is an opening-closing abnormality that is failure both to close and to open, the control unit sends a maintaining command for maintaining the opening degree to the valve driving motor.

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.

A method for operating a fuel cell system having a fuel cell stack includes detecting a failure of a first cooling fan that blows exterior air to a first radiator, opening a first valve such that first cooling water that passes via the fuel cell stack flows toward the fuel cell stack, controlling an RPM of a blower of an air conditioning system to a maximum level, controlling an opening degree of a second valve according to a cooling degree of the first radiator and a cooling degree of the air conditioning system, and controlling an RPM of a first pump that pumps the first cooling water to a maximum level.

a fuel cell system without a high pressure line of a hydrogen supplying system, including a gas charging line formed between a gas charging station and a high pressure vessel charged with gas by the gas charging station, and a gas supplying line formed between the high pressure vessel and a stack, includes: a regulator provided in the gas supplying line; a solenoid valve provided in the gas supplying line between the regulator and the high pressure vessel; and a check valve provided in a bypass line connecting one point of the gas supplying line between the regulator and the solenoid valve and one point of the gas charging line.

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.

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 system for determining performance of a fuel cell stack may include a vehicle that collects a current of the fuel cell stack and a current of the fuel cell stack and a server that receives the voltage of the fuel cell stack and the current of the fuel cell stack from the vehicle in real time, determines an average state of health (SOH) of the fuel cell stack for each current section within an effective current range based on the current of the fuel cell stack and the voltage of the fuel cell stack within the effective current range, determines an overall average SOH in the effective current range based on the average SOH of the fuel cell stack for each current section, and determines whether the fuel cell stack has failed based on the overall average SOH.

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 method and apparatus for detecting oxidation in at least one planar fuel cell stack that includes a multitude of cells is described. The height of the stack is measured to determine if there has been an increase from a previously-measured height. Such an increase correlates with the oxidation of at least some of the planar cells. In some cases, the fuel flow rate or airflow rate to each fuel cell stack can be adjusted, based in part on the oxidation detection technique. A power delivery system with at least two fuel cell stacks is also described, and it includes a stack height-measurement system, a health monitor for the fuel cell stacks, and a load balancer or airflow regulator.