Abstract: When such an abnormality that a battery voltage system voltage is brought into an overvoltage state during regenerative control of a motor occurs, a booster converter is shut down, a system main relay is brought into a non-arc state and turned off. Then, an engine is started when an operation of the engine is stopped. The booster converter is used to determine turning-off of the system main relay, and a battery-less travel is started thereafter. In this way, inconvenience that possibly occurs by starting the battery-less travel at a time when abnormality of the system main relay being stuck to be on occurs can be avoided.

Abstract: When such an abnormality that a battery voltage system voltage is brought into an overvoltage state during regenerative control of a motor occurs, a booster converter is shut down, a system main relay is brought into a non-arc state and turned off. Then, an engine is started when an operation of the engine is stopped. The booster converter is used to determine turning-off of the system main relay, and a battery-less travel is started thereafter. In this way, inconvenience that possibly occurs by starting the battery-less travel at a time when abnormality of the system main relay being stuck to be on occurs can be avoided.

Abstract: During an intermittent operation of the fuel cell, a demanded FC voltage calculation portion calculates a predetermined voltage that is below a heightened potential avoidance threshold voltage as a demanded FC voltage, and outputs the voltage to a converter. When during the intermittent operation of the fuel cell, a deviation obtained by subtracting a generated power of the fuel cell from a system's allowable power that is allowable in the fuel cell system becomes less than or equal to a value 0, the demanded FC voltage correction portion corrects a command value provided for the converter so that the deviation becomes equal to the value 0.

Abstract: During an intermittent operation of the fuel cell, a demanded FC voltage calculation portion calculates a predetermined voltage that is below a heightened potential avoidance threshold voltage as a demanded FC voltage, and outputs the voltage to a converter. When during the intermittent operation of the fuel cell, a deviation obtained by subtracting a generated power of the fuel cell from a system's allowable power that is allowable in the fuel cell system becomes less than or equal to a value 0, the demanded FC voltage correction portion corrects a command value provided for the converter so that the deviation becomes equal to the value 0.