Abstract: A fuel cell system includes a fuel cell, a reactant gas supply device, a voltage adjusting device, a load, and a control device. The control device executes a fixed voltage/variable output control where, in a state where an output voltage of the fuel cell is fixed to a voltage value outside of a redox advancing voltage range using the voltage adjusting device, a supply amount of reactant gas supplied from the reactant gas supply device to the fuel cell is changed so as to track a request output of the load. The control device restricts a change rate of the supply amount of the reactant gas supplied from the reactant gas supply device to the fuel cell if there is change in the request output of the load while the fixed voltage/variable output control is being executed.

Abstract: A fuel cell vehicle is provided. The voltage of a fuel cell is fixed, by a DC/DC converter, to a voltage outside an oxidation reduction progress voltage range of the fuel cell. In this state, oxygen concentration or hydrogen concentration is decreased by a gas supply unit, and electric power outputted from the fuel cell is decreased. In this state, regenerative electric power generated by regeneration is collected into a battery.

Abstract: A fuel cell vehicle is provided. At the time of regeneration of electric power by a motor, an ECU places a DC/DC converter in a direct connection state under control, and stores electric power in a battery while decreasing oxygen concentration or hydrogen concentration by a gas supply unit to decrease electric power generated by a fuel cell.

Abstract: In a fuel cell system, regeneration-time voltage fixed control is implemented where during regeneration or when regeneration is expected to occur, output voltage of a fuel cell is set to a voltage value outside an oxidation reduction progress voltage range, and the amount of reactant gas supplied to the fuel cell is changed based on the amount of electric power remaining in an energy storage device. In the regeneration-time voltage fixed control, it is determined whether or not regeneration occurs while a moving body equipped with the fuel cell system is moving down a slope, and in the case where it is determined that regeneration occurs while the moving body is moving down a slope, the amount of the reactant gas supplied to the fuel cell is decreased in comparison with the case where it is determined that regeneration occurs while the moving body is not moving down a slope.

Abstract: A fuel cell vehicle is provided. The voltage of a fuel cell is fixed, by a DC/DC converter, to a voltage outside an oxidation reduction progress voltage range of the fuel cell. In this state, oxygen concentration or hydrogen concentration is decreased by a gas supply unit, and electric power outputted from the fuel cell is decreased. In this state, regenerative electric power generated by regeneration is collected into a battery.

Abstract: A fuel cell vehicle comprises a motor , a fuel cell , a first DC/DC converter, and a first converter control unit . The first DC/DC converter performs a boosting operation when the fuel cell vehicle runs in a non-stationary state, and does not perform the boosting operation during the vehicle runs in a stationary state.

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: A fuel cell vehicle has a fuel cell for generating electric power by being supplied with a reactive gas, an electric storage device, a first power supply line connected to the fuel cell, a second power supply line connected to the electric storage device, and a main DC-to-DC converter for performing bidirectional voltage conversion between the first power supply line and the second power supply line, an electric motor to propel the vehicle and a first electric accessory connected to the first power supply line, a second electric accessory having at least a portion connected to the second power supply line.

Abstract: A fuel cell system and a fuel cell vehicle equipped with the fuel cell system are provided. In a case where the voltage of a battery is outside a voltage range of fuel cells where oxidation-reduction proceeds, an ECU controls a DC/DC converter to be placed in a direct connection state (Vbat?Vfc), and controls a gas supply unit so as to regulate concentration of oxygen or hydrogen supplied to the fuel cells in accordance with a target power generation electric power determined based on electric power required by a load.

Abstract: In an FC system of an FC vehicle, if a control device determines that conditions of an idling power generation suppression mode of a FC are satisfied, the control device sets the voltage of the FC to a predetermined voltage value outside a voltage range where an oxidation-reduction of platinum proceeds, and controls a reactant gas supply apparatus to change a supply amount of air such that the FC has an output in accordance with the electric power required by a load.

Abstract: In a case where gas supply controller of an FC system determines that the temperature of an FC is a predetermined temperature or less, the gas supply controller fixes the FC voltage to a voltage value within a voltage region where degradation is relatively small, the voltage value being below a voltage range where an oxidation-reduction proceeds. Further, the amount of a gas supplied to the FC is changed in accordance with electric power required by a load.

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, a first electric accessory serving as at least part of a fuel cell accessory for operating the fuel cell, a first DC-to-DC converter for performing bidirectional voltage conversion between the first power supply line and the second power supply line and a second DC-to-DC converter for lowering a voltage for supply electric power to the first electric accessory.

Abstract: An electric power supply system can determine a sharing ratio of an electric power so as to increase and decrease an output electric power supplied by an electric power generator in accordance with an output electric power value required for the electric power supply system, in a fuel cell following region where a frequency of a magnitude of the electric power is equal to or higher than a predetermined value in a frequency distribution of a magnitude of the electric power, and can determine the sharing ratio of the electric power so as to increase an output electric power supplied by an electricity storage device, in an assist region where the frequency is lower than a predetermined value in the frequency distribution, and can prevent an excess of discharging from an electricity storage device.

Abstract: Provided is a fuel cell system for having a fuel cell generate electric power corresponding to a requirement by a power consuming load, with improving the durability of the fuel cell. The fuel cell system comprises: a fuel cell stack, an air pump, a first convertor, a motor, an ECU controlling the air pump and the first convertor based on the target voltage and switching voltage of the single cell. The ECU executes the first mode such that the actual voltage of the single cell corresponds to the target voltage, when the target voltage is not more than the switching voltage, while the ECU executes the second mode such that the actual voltage of the single cell is kept at the switching voltage, when the target voltage is more than the switching voltage. The second mode is executed by changing the actual current of the single cell.

Abstract: An electric power supply system can determine a sharing ratio of an electric power so as to increase and decrease an output electric power supplied by an electric power generator in accordance with an output electric power value required for the electric power supply system, in a fuel cell following region where a frequency of a magnitude of the electric power is equal to or higher than a predetermined value in a frequency distribution of a magnitude of the electric power, and can determine the sharing ratio of the electric power so as to increase an output electric power supplied by an electricity storage device, in an assist region where the frequency is lower than a predetermined value in the frequency distribution, and can prevent an excess of discharging from an electricity storage device.

Abstract: Under the same target voltage, a basic duty ratio depending on a target ON time is set, and prior and subsequent duty ratios before and after upper arm switching devices or lower arm switching devices are driven with the basic duty ratio are set as a basic duty ratio+? and a basic duty ratio??, respectively. Gate drive signals, having the basic duty ratio and the prior and subsequent duty ratios, are supplied to the upper arm switching devices or to the lower arm switching devices, in order to turn on the upper arm switching devices or the lower arm switching devices.

Abstract: A control device for starting a fuel cell is provided which is capable of preventing an excessive reduction of the terminal voltage of the fuel cell. A primary precharge portion, provided with a high voltage switch and a current limiter, is disposed at the output portion of a power storage unit, and a secondary precharge portion, provided with a DC-DC chopper and a control portion, is disposed at the output side of a fuel cell. The primary precharge portion controls the output current to flow in a path via a resistor having a predetermined resistance. The secondary precharge portion controls an output current of the fuel cell based on a current command value IFCCMD for the fuel cell.

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: A fuel cell vehicle capable of improving energy efficiency by reducing switching loss is provided. The fuel cell vehicle includes: a fuel cell that generates direct current power; inverters which respectively include switching elements and convert the direct current power generated by the fuel cell into alternating current power; a diode that prevents current from flowing from the inverters toward the fuel cell; a step up/down DC/DC converter that adjusts the voltage of the cathode side of the diode; a voltage control part that controls the step up/down DC/DC converter, thereby controlling current output from the fuel cell; and a stop and idle determination part that stops the supply of air to the fuel cell, thereby stopping idling of the fuel cell. The voltage control part reduces the voltage of the cathode side of the diode as the voltage of the fuel cell is reduced by activating the stop and idle determination part.

Abstract: A fuel cell vehicle system includes: a propulsion motor capable of driving a vehicle; a fuel cell which generates electric power by supplying a reactant gas to give an electrochemical reaction; an energy storage device which is charged by a generated output of the fuel cell and regenerative electric power of the propulsion motor; an output control device which controls an output current of the fuel cell; and a control device which calculates the regenerative electric power which can be generated by a regenerative operation of the propulsion motor as well as a chargeable power which can be charged to the energy storage device, controls the output control device so that the output current of the fuel cell is restricted when the chargeable power is less than the regenerative electric power, and controls the output control device so that restriction on the output current of the fuel cell is canceled when the chargeable power is equal to or greater than the regenerative electric power.