Abstract: When the current state of fuel cells 30 suggests a potential for an impending output restriction, the control procedure of the invention raises a target SOC level of a secondary battery 60 (step S170), and sets a charge level restriction Wch (step S180) to make the fuel cells 30 keep its current state having the potential for the impending output restriction. The control procedure charges the secondary battery 60 in the range of the set charge level restriction Wch (step S210) and causes a motor 36 to output a torque at a level of a preset torque demand Td* (step S230). The secondary battery 60 is thus chargeable without making the state of the fuel cells 30 approach to conditions for imposing an output restriction and is prepared for possible output restriction of the fuel cells 30.

Abstract: A fuel cell system in accordance with the present invention comprises a fuel cell connected to a load for supplying power thereto; a voltage regulating unit connected between the fuel cell and the load for controlling a voltage between the terminals of the load; a rectifier, which is connected to the fuel cell side from the connection portion with the voltage regulating unit, and which is between the fuel cell and the load, for preventing the reverse flow of a fuel cell current; and a current sensor for detecting a fuel cell current. This fuel cell system detects the output of the current sensor after the voltage between the terminals of the load has been raised by the voltage regulating unit and determines the correction value of the fuel cell current detected with the current sensor based on the detected current sensor output.

Abstract: A fuel battery system capable of quickly consuming residual hydrogen gas even if a surplus power consumption means has a limitation. During shutdown of the system, a fuel battery (10) is made to generate power by using the surplus fuel gas to charge a secondary battery (41), and non-storable surplus power is consumed by consumption means (22, 33, 13). When the surplus power generated by the fuel cell is consumed by the consumption means, any limitation in the system is detected, and the power generated by the fuel battery is changed depending on the detected limitation.

Abstract: The measurement precision of a current detector of the fuel cell in a fuel cell system is improved. Where the fuel cell system 20 has not started operation, the vehicle 10 is operating under regenerative operation, the fuel cell 21 is operating under intermittent operation, or operation of the fuel cell system 20 has ended, the output terminal voltage of the fuel cell 21 is set to the OCV value of 400V via the DC/DC converter 31. As a result, even where the status of the fuel cell 21 changes from operating to stopped, the value of the current flowing over the power supply lines 411 can be immediately and reliably set to 0 A. The control unit 60 then obtains the current value Ad from the fuel cell current sensor 413 (step S150), and determines the offset correction value Ac needed in order to cancel the drift amount (i.e., in order to perform zero-point correction).