A voltage synchronization method and system are provided. The system includes a main controller that is configured to determine whether voltage synchronization is possible. When the voltage synchronization is determined to be possible, the main controller is configured to transmit a voltage synchronization command to a plurality of auxiliary controllers. The plurality of auxiliary controllers are configured to adjust sensed voltages based on an output voltage of a fuel cell stack when the transmitted voltage synchronization command is received.

A fuel cell vehicle includes a fuel cell, a first electric component, a second electric component, a battery, a first switch, a second switch, and circuitry. The first electric component is to operate the fuel cell. The second electric component is not to be used to operate the fuel cell. The first switch is to electrically connect the first electric component to the battery to supply electric power from the battery to the first electric component. The second switch is to electrically connect the second electric component to the battery to supply electric power from the battery to the second electric component. The circuitry is configured to control the first switch to electrically connect the first electric component to the battery and to control the second switch not to electrically connect the second electric component to the battery when the fuel cell is started.

A system and method for operating a fuel-cell system, which is attached to at least one further component via a cooling and/or lubricating circuit. A water-based, oil-free coolant and lubricant is used, and a flushing procedure for the fuel cell is initiated when a contamination of the fuel cell by the water-based, oil-free coolant and lubricant is detected.

A system and method for recovering an output of a fuel cell is provided. The system and method for recovering an output of a fuel cell includes: an output recovering device connected to a fuel cell stack through at least one coolant heater line; and a vehicle controller configured to communicate with the output recovering device and control supply of a coolant, air, and hydrogen to the fuel cell stack. The output recovering device also includes a current supplier configured to supply a current to the fuel cell stack and a controller configured to communicate with the vehicle controller and control the current supplied from the current supplier.

Systems and methods are provided for monitoring and controlling pump speeds to maintain a balanced pressure drop between each of the multiple fuel cell systems or circuits. In systems where a single radiator is used to maintain desired temperatures of multiple fuel cells, back flow can nevertheless be avoided. Control maps may be used to meet minimum pump speeds as a function of a flow splitting valve position and target flow rate (to prevent or avoid fluid back flow through a fuel cell stack). Control maps may also be used to determine a minimum pump speed as a function of three-way valve position (to prevent fluid back flow across a radiator path).

Systems and methods are provided for monitoring and controlling pump speeds to maintain a balanced pressure drop between each of the multiple fuel cell systems or circuits. In systems where a single radiator is used to maintain desired temperatures of multiple fuel cells, back flow can nevertheless be avoided. Control maps may be used to meet minimum pump speeds as a function of a flow splitting valve position and target flow rate (to prevent or avoid fluid back flow through a fuel cell stack). Control maps may also be used to determine a minimum pump speed as a function of three-way valve position (to prevent fluid back flow across a radiator path).

Disclosed is a method for driving an range extending system for a motor vehicle equipped with an electric motor (2) adapted to be supplied with electric current by a traction battery (3), the range extending system including an range extender (1) that can be activated to supply the traction battery and/or the electric motor with electric current and a cooling circuit (10) for the range extender, in which provision is made to acquire a state of charge of the traction battery and, if the state of charge is below a charge threshold, to activate the range extender. Additionally, the charge threshold has a variable value, which is a function of an outside temperature of the air outside the motor vehicle.

An air compressor control method for a fuel cell vehicle is provided. The method includes sensing variation information of a rotation speed of an air compressor motor and sensing a state of charge (SOC) of a high voltage battery by the fuel cell controller when the rotation speed of the air compressor motor is reduced. An allowable current from regenerative braking of an air compressor is derived using current consumption of an electric or electronic sub-assembly for a fuel cell vehicle in response to determining that the SOC exceeds a predetermined level of the SOC. The air compressor motor is then operated based on the allowable current from regenerative braking by an air compressor controller.

An air-cooled fuel-cell vehicle includes: a drive motor for the vehicle; an air-cooled fuel cell; an intake duct which is placed on a vehicle front side relative to the fuel cell and guides air to the fuel cell; an air-intake shutter mechanism which opens and closes the intake duct; a storage chamber provided on the vehicle front side relative to a passenger compartment of the vehicle and accommodates the fuel cell, the intake duct, and the air-intake shutter mechanism; a controlling portion which controls the air-intake shutter mechanism; and a collision detector which detects a front collision of the vehicle. The controlling portion controls the air-intake shutter mechanism to a closed side when the front collision of the vehicle is detected, and the intake duct includes a tubular metal plate portion or a resin portion containing an elastomer component.

A saddle-ride type vehicle includes an air-cooled fuel cell unit that is mounted on a body frame behind a head pipe and in front of a pivot frame and uses taken-in outside air for supplying oxygen and cooling a unit. The fuel cell unit includes an outside air intake open forward below the head pipe and an exhaust port open rearward above a pivot. A seat frame has a monocoque structure also having a configuration of an exhaust duct for guiding exhaust gas from the fuel cell unit to a back of an occupant's seat. Accordingly, in the saddle-ride type vehicle, it is possible to realize more efficient ventilation in utilizing a fuel cell.