A fuel cell system includes an air compressor that supplies oxidant gas to a fuel cell installed in a fuel cell vehicle, a measured rotational speed acquirer that acquires a measured value of rotational speed of the air compressor, and a controller that calculates a rotational speed command value of the air compressor based on required generated power of the fuel cell, calculates a torque command value of the air compressor based on the calculated rotational speed command value and current rotational speed of the air compressor, and controls rotational speed of the air compressor based on the calculated torque command value. The controller estimates the current rotational speed of the air compressor baaed on the measured value of the rotational speed acquired by the measured rotational speed acquirer and a history of the calculated torque command value, and calculates the torque command value by using the estimated rotational speed.

A fuel cell system includes an air compressor that supplies oxidant gas to a fuel cell installed in a fuel cell vehicle, a measured rotational speed acquirer that acquires a measured value of rotational speed of the air compressor, and a controller that calculates a rotational speed command value of the air compressor based on required generated power of the fuel cell, calculates a torque command value of the air compressor based on the calculated rotational speed command value and current rotational speed of the air compressor, and controls rotational speed of the air compressor based on the calculated torque command value. The controller estimates the current rotational speed of the air compressor baaed on the measured value of the rotational speed acquired by the measured rotational speed acquirer and a history of the calculated torque command value, and calculates the torque command value by using the estimated rotational speed.

A gas detection system is for detecting the remaining amount of gas in a gas tank that stores a predetermined gas. The gas detection system includes: a gas detector that detects the predetermined gas; and a shutter (e.g., a pressure detector) that is connected between the gas tank and the gas detector and opens and closes a path of the predetermined gas from the gas tank to the gas detector.

A fuel cell system includes a fuel cell, an air supplier that supplies air to a cathode of the fuel cell, a flow rate sensor that senses an air flow rate, and a silencer that reduces sound of a certain frequency through interference of an acoustic wave, the flow rate sensor, the air supplier, and the fuel cell being arranged in an air passage in series in order named from an upstream side of flow of the air, the silencer being arranged in a branch portion of the air passage, the branch portion being between the flow rate sensor and the air supplier.

A vehicle which includes a fuel cell, a receptacle, a lid, and a fixing pin, and which stores a detection of the open state during a period from a time point of a latest end of operation of the vehicle to a time point of input acceptance of a start-up instruction. If a detection of an open state has been stored in a memory at a time point of input acceptance of a start-up instruction, then the vehicle executes a retry operation of temporarily moving the fixing pin of the fixed position to the released position and thereafter moving the fixing pin again to the fixed position during an operating period of the vehicle from the time point of input acceptance of the start-up instruction.

A vehicle which includes a fuel cell, a receptacle, a lid, and a fixing pin, and which stores a detection of the open state during a period from a time point of a latest end of operation of the vehicle to a time point of input acceptance of a start-up instruction. If a detection of an open state has been stored in a memory at a time point of input acceptance of a start-up instruction, then the vehicle executes a retry operation of temporarily moving the fixing pin of the fixed position to the released position and thereafter moving the fixing pin again to the fixed position during an operating period of the vehicle from the time point of input acceptance of the start-up instruction.

A fuel cell includes: a stack having a manifold in which a fluid flows and having a plurality of flowing spaces which communicate with the manifold through openings; a shielding part having a plurality of shielding strips arranged in a stacked direction of the stack and selectively moving along the manifold to shield at least some of the plurality of flowing spaces; and a driver coupled with the shielding part to move the shielding part.

A fuel cell includes: a stack having a manifold in which a fluid flows and having a plurality of flowing spaces which communicate with the manifold through openings; a shielding part having a plurality of shielding strips arranged in a stacked direction of the stack and selectively moving along the manifold to shield at least some of the plurality of flowing spaces; and a driver coupled with the shielding part to move the shielding part.

A vehicle includes an electric motor, a fuel cell, and a fuel cell thermal management system. A control system of the vehicle is configured to operate the fuel cell and the fuel cell thermal management system according to different modes. The modes include an acoustic signature mode in which an acoustic signature of the vehicle is reduced, a thermal signature mode in which a thermal signature of the vehicle is reduced, an acoustic and thermal signature mode in which both the acoustic signature and the thermal signature of the vehicle are reduced, a mission mode in which the vehicle is a node of a mesh network of other vehicles, and an optimized efficiency mode in which the fuel cell and the fuel cell thermal management system are controlled based on ambient conditions.

A vehicle includes an electric motor, a fuel cell, and a fuel cell thermal management system. A control system of the vehicle is configured to operate the fuel cell and the fuel cell thermal management system according to different modes. The modes include an acoustic signature mode in which an acoustic signature of the vehicle is reduced, a thermal signature mode in which a thermal signature of the vehicle is reduced, an acoustic and thermal signature mode in which both the acoustic signature and the thermal signature of the vehicle are reduced, a mission mode in which the vehicle is a node of a mesh network of other vehicles, and an optimized efficiency mode in which the fuel cell and the fuel cell thermal management system are controlled based on ambient conditions.