Abstract: An electric system has a fuel cell for generating electric power by being supplied with a reactive gas, an electric storage device having a voltage lower than a voltage output from the fuel cell, a first power supply line connected to the fuel cell, a second power supply line connected to the electric storage device, and a first DC-to-DC converter for performing bidirectional voltage conversion between the first power supply line and the second power supply line. An inverter, a propulsive electric motor, and an air compressor are supplied with electric power from the first power supply line. An electrically operated air conditioner motor, windshield wiper motors, and power window motors, etc., which serve as a second electric accessory, are supplied with electric power from the second power supply line.

Abstract: A method of determining voltage conditions of a fuel cell vehicle which includes a motor as a driving force source of the vehicle, a motor control device for controlling operation of the motor, a fuel cell, to which a reaction gas is supplied, for generating electric power by an electrochemical reaction, and a battery device which is charged by the electric power generated by the fuel cell and sends and receives electrical energy to and from the motor by control of the motor control device. The method includes setting a voltage value, typically an average value, of an output voltage of the fuel cell within a range from a minimum value to a maximum value of an open circuit voltage of the battery device. Even when the fuel cell and the battery device are directly connected, overcharge or overdischarge can be prevented, thereby reducing frequency of voltage conversion.

Abstract: When the output of a fuel cell starts to decrease, in consideration of the increase in the power generation efficiency, an instruction for the output of the fuel cell undergoes a smoothing process to gradually decrease the output, and excessive electric power generated during a period in which the power generation efficiency is high is used for charging a battery. While the output of the fuel cell is increasing, the power generation efficiency of the fuel cell is low. Thus, assisting electrical energy from the battery is increased. In this manner, the power generation output when the power generation efficiency of the fuel cell is low is reduced from a high power generation output to a low power generation output to achieve improvement in the average power generation efficiency.

Abstract: An idle control system applicable to a fuel cell vehicle 1 is provided for improving the fuel efficiency. When the fuel cell vehicle is determined to be in a predetermined idle mode, the idle control system stops a compressor to thereby stop power generation of a fuel cell. In contrast, when the state of charge of the capacitor 4 falls below a predetermined value while the fuel cell vehicle is in the idle mode, the idle control system drives the compressor 8 by means of the capacitor to drive the fuel cell in order to charge the capacitor.

Abstract: This power supply system of a fuel cell vehicle is provided with a load, a fuel cell, a power storage device, a first DC-DC converter, a second DC-DC converter, a current-measuring device, a voltage-measuring device, and a controller. The controller performs a feedback control of the first DC-DC converter such that input current or output current measured by the current-measuring device becomes a target current, and also performs a feedback control of the second DC-DC converter such that input voltage or output voltage measured by the voltage-measuring device becomes a target voltage.

Abstract: This control method for a fuel cell vehicle includes: a target motor output power obtaining step which obtains a target motor output power corresponding to an accelerator opening degree; and a high output power control step which controls operations of a first DC-DC converter and a second DC-DC converter, such that an output voltage of a power source becomes equal to or larger than a predetermined voltage that is required for securing a desired motor output power, when the target motor output power is larger than a predetermined output power threshold value.

Abstract: A control apparatus 20 is provided in order to improve the energy efficiency of a vehicle during regeneration by a propulsion motor. At the time of regenerative operation of a propulsion motor 15, calculates the regenerative electric power which can be generated based on the speed of the vehicle or the like, and calculates the chargeable power which can be charged to a capacitor 13 based on the detected value of the terminal voltage of the capacitor 13 or the like.

Abstract: When a control device detects a request for stopping power generation of a fuel cell, electrical energy discharged from the fuel cell is supplied to an energy storage and other electrical devices such as an air compressor. At this time, electrical energy is supplied preferentially to the other electrical devices. Accordingly, discharge/charge losses in the energy storage can be reduced, compared to a technique in which an energy storage is charged preferentially at the time of stopping power generation of a fuel cell.

Abstract: A control apparatus 20 is provided in order to improve the energy efficiency of a vehicle during regeneration by a propulsion motor. At the time of regenerative operation of a propulsion motor 15, calculates the regenerative electric power which can be generated based on the speed of the vehicle or the like, and calculates the chargeable power which can be charged to a capacitor 13 based on the detected value of the terminal voltage of the capacitor 13 or the like.

Abstract: A fuel cell system installed in a fuel-cell movable body. The system includes a fuel cell for generating electric power using reaction gases; a plurality of sensors for measuring states of the fuel cell; an abnormal state detecting device for detecting an abnormal state of at least one of said plurality of sensors; a substitution possibility determining device for determining whether there are one or more substitution sensors from among said plurality of sensors, each substitution sensor outputting a signal value used for setting a substitutional value for a signal value output from the sensor whose abnormal state has been detected; and a predetermined operation control device for operating the fuel cell in a predetermined operation state when the abnormal state of the sensor is detected by the abnormal state detecting device and it is determined by the substitution possibility determining device that there is no substitution sensor.

Abstract: A management ECU of a control unit predicts the reduction degree of a system voltage according to an operational state of a motor based on the temperature of a fuel cell and a number of rotations of the motor, sets motor output restriction start voltage and motor output restriction end voltage which are threshold values of the system voltage for triggering an execution start and an execution end of a processing to restrict an output of the motor, and outputs them to a motor ECU. The motor ECU sets an output restriction coefficient that is a restriction rate in restricting the output of the motor based on a detected value of the system voltage and the motor output restriction start voltage and the motor output restriction end voltage, and restricts the output of the motor.

Abstract: An electric system has a fuel cell and an electric storage device which are connected in parallel to each other with respect to a propulsive motor, and a DC-to-DC converter connected closer to the electric storage device than a junction where the fuel cell and the electric storage device are connected in parallel to each other. An electric power control system includes a power supply controller having a failure detector for detecting a failure of the DC-to-DC converter. When the failure detector detects a failure of the DC-to-DC converter, the response of electric power output from the fuel cell is limited.

Abstract: An electric system has a fuel cell for generating electric power by being supplied with a reactive gas, an electric storage device having a voltage lower than a voltage output from the fuel cell, a first power supply line connected to the fuel cell, a second power supply line connected to the electric storage device, and a first DC-to-DC converter for performing bidirectional voltage conversion between the first power supply line and the second power supply line. An inverter, a propulsive electric motor, and an air compressor are supplied with electric power from the first power supply line. An electrically operated air conditioner motor, windshield wiper motors, and power window motors, etc., which serve as a second electric accessory, are supplied with electric power from the second power supply line.

Abstract: A fuel cell vehicle can reduce the starting time while protecting the fuel cell. When starting the vehicle, a control apparatus execute an idle charging an output voltage (estimated output voltage) of the fuel cell immediately after the vehicle commences movement, in the condition where, while in the idle charging state at the time of starting the fuel cell vehicle, e.g., the state wherein generation of power by the fuel cell continues, and the value of the output current extracted from the fuel cell is being restricted to an appropriate value by a current and voltage controller, a capacitor is being charged with the restricted current. Then, the control apparatus, when detecting that the increased terminal voltage of the capacitor due to charging from the fuel cell has gone above the estimated output voltage, outputs to an output controller a control command to start power supply to a propulsion motor.

Abstract: When a power generation stop signal of an ignition switch is detected, an oxygen-containing gas is supplied to an anode for starting an anode scavenging process. After starting the anode scavenging process, the remaining electrical energy stored in a capacitor is monitored. If the monitored remaining electrical energy stored in the capacitor is decreased to a threshold, the anode scavenging process is finished. At the end of the anode scavenging process, the remaining electrical energy becomes equal to the threshold. By the remaining electrical energy equal to the threshold, the next operation of the fuel cell system is reliably started. Since the anode scavenging process continues until the remaining electrical energy is decreased to the threshold, the time for the anode scavenging process can be increased as much as possible.

Abstract: Disclosed is a fuel cell power supply device in which an I-V characteristics estimating unit estimates output current/voltage characteristics (I-V characteristics) of a fuel cell by substituting a linear function (V=F(I)) in which a gradient indicates an internal resistance of the fuel cell and an interception of an axis representing a voltage (V) indicates an open-circuit voltage of the fuel cell calculated by a fuel cell open-circuit voltage calculator for the I-V characteristics. On the basis of the I-V characteristics of the fuel cell estimated by the I-V characteristics estimating unit, a requested output voltage determining unit and a requested output current determining unit determine a requested output voltage and a requested output current, respectively, which are needed to obtain a target total electric energy.

Abstract: A fuel cell power supply has a fuel cell and a capacitor which are connected parallel to each other, and controls the amount of a reacting gas supplied to the fuel gas based on a target supply current. A capacitor open voltage calculator calculates an open voltage (Vcap_O) of the capacitor from a detected current (Icap) of the capacitor, an output voltage (Vout) of the fuel cell, and an internal resistance (Rcap) of the capacitor. A corrective quantity calculator calculates a corrective quantity (Ifc_AM) for a target supply current (Ifc_REQ) based on the open voltage (Vcap_O) of the capacitor, the output voltage (Vout) of the fuel cell, and the target supply current (Ifc_REQ), so as to prevent an air compressor from operating excessively and also prevent the fuel cell from suffering a gas shortage, depending on current-voltage characteristic data (Icap?Vcap) of the fuel cell and current-voltage characteristic data (Ifc?Vcap) of the capacitor.

Abstract: A fuel cell power supply has a fuel cell and a capacitor which are connected parallel to each other, and controls the amount of a reacting gas supplied to the fuel gas based on a target supply current. A capacitor open voltage calculator calculates an open voltage of the capacitor from a detected current of the capacitor, an output voltage of the fuel cell, and an internal resistance of the capacitor. A corrective quantity calculator calculates a corrective quantity for a target supply current based on the open voltage of the capacitor, the output voltage of the fuel cell, and the target supply current, so as to prevent an air compressor from operating excessively and also prevent the fuel cell from suffering a gas shortage, depending on current-voltage characteristic data of the fuel cell and current-voltage characteristic data of the capacitor.

Abstract: A fuel cell vehicle includes a fuel cell, a rotating load, a energy storage, a contactor, a DC-DC converter, and a control unit. When regeneration by the energy storage is performed, the DC-DC converter connected to the energy storage is placed in a direct connection mode for directly charging regeneration electrical energy from a motor of the rotating load to the energy storage.

Abstract: A method of determining voltage conditions of a fuel cell vehicle which includes a motor as a driving force source of the vehicle, a motor control device for controlling operation of the motor, a fuel cell, to which a reaction gas is supplied, for generating electric power by an electrochemical reaction, and a battery device which is charged by the electric power generated by the fuel cell and sends and receives electrical energy to and from the motor by control of the motor control device. The method includes setting a voltage value, typically an average value, of an output voltage of the fuel cell within a range from a minimum value to a maximum value of an open circuit voltage of the battery device. Even when the fuel cell and the battery device are directly connected, overcharge or overdischarge can be prevented, thereby reducing frequency of voltage conversion.