Supply of electric power using fuel cell and chargeable/dischargeable storage

Power supply using fuel cell and rechargeable power storage unit

Technical field

The present invention relates to power supply using a fuel cell and a chargeable and dischargeable power storage unit.

Background technique

In recent years, in consideration of the global environment, electric vehicles and dual-power vehicles equipped with an electric motor powered by a fuel cell as a driving force source have been proposed. The so-called fuel cell refers to a device that generates electricity through an electrochemical reaction that oxidizes hydrogen gas. Since water vapor is mainly discharged from fuel cells, dual-power vehicles or electric vehicles using fuel cells are environmentally superior.

However, fuel cells generally have low responsiveness to the required power output. In other words, when the accelerator is operated abruptly, sometimes the corresponding power cannot be supplied quickly. The reason is that the responsiveness of gas fuel supply is low.

If a large amount of gas fuel can be continuously supplied to the fuel cell regardless of the required power, the output responsiveness can be improved, but a lot of energy will be wasted in the driving of the pump for supplying gas fuel, which is detrimental to energy. Conversion efficiency.

In the prior art, a scheme has also been proposed in which a fuel cell and a storage battery are used together to compensate the response delay of the fuel cell with the power of the storage battery. For example, when the fuel cell and the storage battery are used as power sources, and when the required power change is small enough to enable the fuel cell to track, the fuel cell alone outputs power, and when the required power change is large, both the fuel cell and the storage battery output power. electricity. The battery is properly charged by the fuel cell.

The fuel cell is a device under development recently. Therefore, sufficient research has not been conducted on the possibility of improving the responsiveness by controlling it. In addition, when a fuel cell is used in combination with a rechargeable power source such as a battery, there has not been sufficient research on a power supply method that optimally combines the characteristic advantages of the two.

Disclosure of the Invention An object of the present invention is to provide a technology that ensures the output responsiveness of a fuel cell to the required power and uses it as a power source more effectively.

In order to solve at least a part of the above-mentioned problems, the present invention adopts the following structure.

The first power supply device of the present invention uses a fuel cell and a chargeable and dischargeable power storage unit as a power source to supply power. The power supply device is characterized in that it is equipped with a required power input unit to provide input to the power supply at any time. The storage unit stores the relationship between the required power and the target output value that the fuel cell should output, that is, the slope of the change in the target output value corresponding to the change in the required power is set to not exceed according to The relationship within the range of the predetermined value determined by the output response of the fuel cell; the target output value setting unit refers to the storage unit and sets the target output value based on the required power; the fuel cell control unit, based on the target output value The operation of the fuel cell is controlled; a charging and discharging unit performs charging and discharging of the power storage unit based on the required power and the target output value.

In the present invention, the target output value of the fuel cell is set within a range that does not exceed a predetermined value determined based on the output responsiveness of the fuel cell. In other words, it is set so that the output of the fuel cell can track changes in the required power. In the range. Therefore, the fuel cell can track the target output value and output power stably. As a result, the output of the fuel cell can be smoothly controlled, and excessive charge and discharge of the power storage unit can be suppressed.

If the target output value is set to exceed the range that the fuel cell can track, the operation of the fuel cell will change to an arbitrary state, and therefore, control cannot be actually performed. In the present invention, by limiting the setting range of the target output value, the control of the fuel cell can be maintained. Therefore, the capacity of the fuel cell can be fully utilized. As a result, it is possible not only to suppress excessive charging and discharging of the power storage unit, but also to output electric power with good responsiveness.

Power requirements can be entered with various parameters. For example, when the present invention is applied to a vehicle, for example, the accelerator opening degree may be used as a parameter.

In the power supply device of the present invention, the charging and discharging unit preferably performs control to compensate for the difference between the required power and the power supplied by the fuel cell.

As the power storage unit, for example, a secondary battery or a capacitor can be used. The so-called compensation means that when at least the output of the fuel cell cannot meet the required power, the insufficient part is supplemented by the discharge of the power storage unit. At the same time, it is more ideal that when the output of the fuel cell exceeds the required power, the remaining power can be used for charging.

In the above power supply device, the above relationship may be set such that the target output value is greater than the required power in the first predetermined area where the required power is low. In the second predetermined area where the required power is high, it may be set so that the target output value is smaller than the required power.

Through the above settings, the average operating efficiency of the fuel cell can be improved.

For fuel cells, the power generation efficiency varies with the required power. In most cases, the operating efficiency is high when the required power is low, and the operating efficiency is low when the required power is high. By setting the target output value based on the above relationship, when the required power is low, the remaining power can be output from the fuel cell to charge the power storage unit. When the required power is high, the output of the fuel cell can be suppressed and the output of the power storage unit can make up for the insufficient power. In this way, the fuel cell can be operated in a high efficiency range, and the energy conversion efficiency of the power supply device can be improved.

The first and second regions can be appropriately set in consideration of the power generation efficiency of the fuel cell, the charging efficiency of the power storage unit, the standard average value of the required power during the entire operation period, and the like. If the first area is too wide, the power storage unit will be overcharged. If the second area is too wide, it will cause insufficient charging of the power storage unit. In both cases, the overall energy conversion efficiency of the power supply device will be reduced. When setting the first and second regions, considering the average value of the standard, the charge and discharge of the power storage unit can be balanced and the energy conversion efficiency can be improved.

In addition, in the power supply device of the present invention, it is preferable to further include a detection unit that detects the remaining capacity of the power storage unit. The above relationship is preferably set for each remaining capacity. The target output value setting unit, It is better to consider the above-mentioned remaining capacity when setting the target output value.

For example, the above relationship is preferably a relationship in which the smaller the remaining capacity, the larger the target output value is set.

In this way, when the remaining capacity of the power storage unit decreases, it can be charged by the fuel cell. Since the charge amount of the power storage unit can be easily maintained within a predetermined range, it is possible to reduce the size of the power storage unit and the size of the power supply device.

The second power supply device of the present invention uses a fuel cell and a chargeable and dischargeable power storage unit as a power source to supply power. The power supply device is characterized in that it includes a fuel cell control unit that is based on a predetermined target output value. Control the operation of the fuel cell; a charging and discharging unit that performs charging and discharging of the power storage unit to compensate for the difference between the required power and the power that the fuel cell can output; a rate of change detection unit that detects the rate of change of the required power; target The output value setting unit changes the target output value based on the required power when the absolute value of the rate of change exceeds a predetermined value.

The second power supply device corresponds to a form of limiting the set time of the target output value. By avoiding frequent changes in the target output value, stable operation of the fuel cell can be achieved.

That is, in the present invention, a new target output value is set when the rate of change of the requested power exceeds a predetermined value. When the rate of change is small, the target output value is maintained. In this way, the sensitivity of the setting of the target output value of the fuel cell with respect to small changes in the required power can be reduced. As a result, the fuel cell can be controlled stably. The excess and deficiency of the output of the fuel cell caused by the small change in the required power can be compensated by the power storage unit. Therefore, like the first power supply device, not only can the output response to the requested power be ensured, but also the effective use of the fuel cell can be realized.

The second power supply device also has the advantage of being able to improve the energy conversion efficiency of the entire device. It is assumed that the output of the fuel cell is a constant value, and the power storage unit considers the control for compensating for the excess and deficiency corresponding to the required power. In this case, the larger the difference between the output of the fuel cell and the required electric power, the more electric power compensated by the power storage unit. The power supply in this state can easily lead to unbalanced charging and discharging of the power storage unit. In addition, due to the energy loss that accompanies the charge and discharge process, it will also lead to a decrease in energy conversion efficiency. In the second power supply device, since the target output value of the fuel cell is updated at a predetermined time, the output of the fuel cell can be maintained at a value close to the required power, and thus the power to be compensated by the power storage unit can be suppressed. As a result, the above-mentioned drawbacks can be eliminated, and energy conversion efficiency can be improved.

In the second power supply device, it is preferable that the above-mentioned target output value is corrected based on the change in the remaining capacity. In this way, the remaining capacity of the power storage unit can be kept within the prescribed range relatively easily.

The third power supply device of the present invention uses a fuel cell and a chargeable and dischargeable power storage unit as a power source to supply power. The power supply device is characterized in that it is equipped with a requested power input unit that inputs requested power at any time; The power forecasting unit predicts the future required power after a predetermined time; the target output value setting unit sets the target output that the fuel cell should output at the current time based on the future required power, the current required power, and the output responsiveness of the fuel cell The fuel cell control unit controls the operation of the fuel cell based on the target output value; the charge and discharge unit performs charging and discharging of the power storage unit to compensate for the difference between the current required power and the power that the fuel cell can output.

The third power supply device can change the target output value of the fuel cell based on the prediction for the future, so that the responsiveness can be improved. Furthermore, it is possible to suppress the amount of charge and discharge of the power storage unit.

For the setting of the target output value, for example, it is possible to adopt a form in which the target output value increases with an increase in the future required power, or a form in which the target output value decreases with a decrease in the future required power.

Preferably, the third power supply device also corrects the above-mentioned target output value based on the change in the remaining capacity.

For the prediction of electric power, for example, a load information storage unit that prestores load information defining the future operating state of a load to which electric power is supplied from the electric power supply device may be provided, and the prediction may be made based on the load information.

The load information is, for example, information corresponding to the future operation plan. When the power supply device of the present invention is installed in a vehicle, route information provided from a navigation system can be used as load information.

The route information contains information such as the slope of the road on which the vehicle is traveling. For example, in the case of applying the present invention to an automobile, when there is an uphill in front of the vehicle or when entering a highway, by using the route information, the target output value of the fuel cell can be increased in advance to increase the output.

In addition, power forecasts can also be made using various information such as past history.

The present invention may be configured as a control method of the power supply device in addition to the above-mentioned power supply device. It is also possible to form a power output device by combining a power supply device with a motor that uses it as a power source. Furthermore, it may be configured as an electric vehicle or a dual-power vehicle using the electric motor as a driving force source.

Brief Description of the Drawings Fig. 1 is a schematic configuration diagram of a dual power vehicle according to a first embodiment.

Fig. 2 is an explanatory diagram showing a schematic configuration of the fuel cell system.

FIG. 3 is an explanatory diagram showing the wiring of input and output signals to the control unit 70.

Fig. 4 is an explanatory diagram showing the relationship between the running state of the vehicle and the power source.

FIG. 5 is a flowchart of a power output processing routine in the area MG.

Fig. 6 is an explanatory diagram showing the relationship among remaining capacity SOC, accelerator opening, and target output value.

FIG. 7 is a time chart showing changes in the target output value, actual output, and output of the battery 50 of the fuel cell 60.

FIG. 8 is a time chart as a comparative example showing changes in the target output value, actual output, and output of the battery 50 of the fuel cell 60.

Fig. 9 is a flowchart of a target output value setting process in the second embodiment.

FIG. 10 is a time chart showing changes in the target output value, actual output, and output of the battery 50 of the fuel cell 60.

Fig. 11 is a schematic configuration diagram of a dual power vehicle according to a third embodiment.

Fig. 12 is a flowchart of a power output processing routine of the third embodiment.

Fig. 13 is a flowchart of target output value correction processing.

FIG. 14 is a time chart showing changes in the target output value, actual output, and output of the battery 50 of the fuel cell 60.

Fig. 15 is a schematic configuration diagram of an electric vehicle.

The best mode for carrying out the invention The embodiment of the present invention will be explained based on an example of application to a dual-power vehicle.

(1) Structure of the device: Fig. 1 is a schematic structural diagram of the dual-powered vehicle of the first embodiment. The power sources of the dual-power vehicle in this embodiment are the engine 10 and the electric motor 20. As shown in the figure, the power system of the dual power vehicle of this embodiment has a structure in which the engine 10, the input clutch 18, the electric motor 20, the torque converter 30, and the transmission 100 are connected in series from the upstream side. That is, the crankshaft 12 of the engine 10 is connected to the electric motor 20 through the input clutch 18. By connecting and disconnecting the input clutch 18, the power from the engine 10 can be transmitted intermittently. The rotating shaft 13 of the electric motor 20 is also connected to a torque converter 30. The output shaft 14 of the torque converter 30 is connected to the transmission 100. The output shaft 15 of the transmission 100 is connected to the axle 17 via a differential gear 16. Hereinafter, each component will be described in order.

The engine 10 is a normal gasoline engine. However, the engine 10 has a mechanism that can adjust the opening and closing timing of an intake valve for sucking a mixture of gasoline and air into the cylinder and an exhaust valve for discharging burned exhaust gas from the cylinder with respect to the vertical movement of the piston ( Hereinafter, such a mechanism is referred to as a VVT mechanism). Since the VVT mechanism is well known, its detailed description will be omitted here. In the engine 10, the so-called pumping loss can be reduced by adjusting the opening and closing timing with respect to the up and down movement of the piston to delay the closing of each valve. As a result, when the engine 10 is connected to the electric motor, the torque to be output from the electric motor 20 can be reduced. When gasoline is burned to output power, the VVT mechanism is controlled according to the number of revolutions of the engine 10 so that the valves are opened and closed at the timing when the combustion efficiency is the best.

The electric motor 20 is a three-phase synchronous motor, and includes a rotor 22 provided with a plurality of permanent magnets on the outer peripheral surface, and a stator 24 wound with three-phase coils for forming a rotating magnetic field. The electric motor 20 is driven to rotate by the interaction between the magnetic field generated by the permanent magnet provided in the rotor 22 and the magnetic field formed by the three-phase coil of the stator 24. When the motor 20 is rotated by means of an external force, an electromotive force is generated at both ends of the three-phase coil due to the interaction of the above-mentioned magnetic fields. In addition, a sine wave excitation motor in which the magnetic flux density between the rotor 22 and the stator 24 is distributed sinusoidally in the circumferential direction can also be used for the motor 20, but in this embodiment, a non-sine wave that can output a larger torque is used. Excitation motor.

As a power source for the electric motor 20, a battery 50 and a fuel cell system 60 are provided. However, the main power source is the fuel cell system 60. When the fuel cell system 60 fails, or when it is in a transient operation state that cannot output sufficient power, the storage battery 50 is used as a power source for supplying electric power to the electric motor 20 to make up for the lack of electric power. The electric power of the storage battery 50 is mainly supplied to electric equipment such as the control unit 70 and lighting devices that mainly control the dual-power vehicle.

Between the electric motor 20 and each power source, a switch 84 for switching the connection state is provided. The switch 84 can arbitrarily switch the connection state of the battery 50, the fuel cell system 60, and the electric motor 20. The stator 24 is electrically connected to the battery 50 through the changeover switch 84 and the drive circuit 51. In addition, it is also connected to the fuel cell system 60 through the changeover switch 84 and the drive circuit 52. The drive circuits 51 and 52 are each composed of a transistor inverter, and for each of the three phases of the motor 20, a plurality of transistors are provided in which two of the power supply side and the bus side are set as a set. The driving circuits 51 and 52 are electrically connected to the control unit 70. When the control unit 70 performs PWM (Pulse Width Modulation) control on the turn-on and turn-off times of the transistors of the drive circuits 51 and 52, the three-phase coil of the stator 24 flows through the battery 50 and the fuel cell system 60 as power sources. Simulate three-phase AC to form a rotating magnetic field. As described above, the electric motor 20 functions as a motor or a generator as described above by virtue of the action of the rotating magnetic field. The fuel cell system 60, the storage battery 50, the drive circuits 51, 52, the control unit 70, and the changeover switch 84 function as a power supply device. In addition, the above-mentioned parts, together with the electric motor 20 and the engine 10, will function as a power output device.

Fig. 2 is an explanatory diagram showing a schematic configuration of a fuel cell system. The main components of the fuel cell system 60 are a methanol tank 61 that stores methanol, a water tank 62 that stores water, a combustor 63 that generates combustion gas, a compressor 64 that compresses air, and the combustor 63 and the compressor 64 are arranged in parallel The evaporator 65, the reformer 66 that generates combustion gas through the reforming reaction, the CO reduction unit 67 that reduces the concentration of carbon monoxide (CO) in the combustion gas, and the fuel cell 60A that obtains electromotive force through the electrochemical reaction. The operations of the above-mentioned parts are controlled by the control unit 70.

The fuel cell 60A is a solid polymer electrolyte fuel cell, and is configured by stacking a plurality of battery cells composed of an electrolyte membrane, a cathode, an anode, and a separator. The electrolyte membrane is, for example, a proton conductive ion exchange membrane made of a solid polymer material such as a fluorine-based resin. Both the cathode and the anode are formed of a carbon fabric woven from carbon fibers. The separator is formed of an air-impermeable conductive member such as an air-impermeable dense carbon film formed by compressing carbon powder. Between the cathode and the anode, a flow path for combustion gas and oxidizing gas is formed.

The components of the fuel cell system 60 are connected as follows. The methanol tank 61 is connected to the evaporator 65 through a pipe. The pump P2 provided in the middle of the piping supplies methanol as a raw fuel to the evaporator 65 while adjusting the flow rate. The water tank 62 is also connected to the evaporator 65 by piping in the same manner. The pump P3 provided in the middle of the pipe supplies water to the evaporator 65 while adjusting the flow rate. The piping for methanol and the piping for water merge on the downstream side of the pumps P2 and P3, respectively, and are connected to the evaporator 65.

The evaporator 65 vaporizes the supplied methanol and water. The combustor 63 and the compressor 64 are arranged in parallel with the evaporator 65. The evaporator 65 uses the combustion gas supplied from the burner 63 to boil and vaporize methanol and water. The fuel of the burner 63 is methanol. The methanol tank 61 is connected to the burner 63 through a pipe in addition to the evaporator 65. Methanol is supplied to the combustor 63 by the pump P1 provided in the middle of the pipe. The remaining fuel exhaust gas in the fuel cell 60A that is not consumed in the electrochemical reaction is also supplied to the combustor 63. The burner 63 mainly burns the latter of methanol and fuel exhaust gas. The combustion temperature of the burner 63 is controlled based on the output of the sensor T1, and is maintained at approximately 800°C to 1000°C. When the combustion gas of the combustor 63 is delivered to the evaporator 65, the turbine is rotated, thereby driving the compressor 64. The compressor 64 takes in air from the outside of the fuel cell system 60, compresses it, and supplies the compressed air to the anode side of the fuel cell 60A.

The evaporator 65 and the reformer 66 are connected to each other by pipes. The raw gas fuel obtained by the evaporator 65, that is, the mixed gas of methanol and water, is sent to the reformer 66. The reformer 66 reforms the raw gaseous fuel composed of methanol and water to generate a hydrogen-rich gaseous fuel. In addition, a temperature sensor T2 is installed in the middle of the delivery pipe from the evaporator 65 to the reformer 66 to control the amount of methanol supplied to the burner 63 so that the temperature is usually a predetermined value of about 250°C. In the reforming reaction of the reformer 66, oxygen needs to be added. In order to supply oxygen required for the reforming reaction, a blower 68 for supplying air to the reformer 66 from the outside is also provided in parallel.

The reformer 66 and the CO reduction unit 67 are connected by piping. The hydrogen-rich gas fuel obtained by the reformer 66 is supplied to the CO reduction unit 67. During the reaction process in the reformer 66, a certain amount of carbon monoxide (CO) is usually contained in the gas fuel. The CO reduction unit 67 can reduce the concentration of carbon monoxide in the gas fuel. In the solid polymer fuel cell, the carbon monoxide contained in the gas fuel will affect the reaction of the anode, which is a factor that causes the performance of the fuel cell to decrease. The CO reduction unit 67 can reduce the concentration of carbon monoxide by oxidizing carbon monoxide in the gas fuel to carbon dioxide.

The CO reduction unit 67 and the anode of the fuel cell 60A are connected by piping. The gas fuel in which the concentration of carbon monoxide is reduced is used for the cell reaction on the cathode side of the fuel cell 60A. In addition, as described above, the piping for feeding compressed air is connected to the cathode side of the fuel cell 60A. This air is used as an oxidizing gas for the cell reaction on the anode side of the fuel cell 60A.

The fuel cell system 60 having the above structure can supply electric power by using a chemical reaction of methanol and water. In this embodiment, a fuel cell system 60 using methanol and water is installed, but the fuel cell system 60 is not limited to this, and various structures using reformed gasoline and natural gas, or pure hydrogen, etc. may be adopted. In addition, in the following description, the fuel cell system 60 is collectively referred to as a fuel cell 60.

The torque converter 30 (FIG. 1) is a well-known power transmission mechanism using fluid. The input shaft of the torque converter 30, that is, the output shaft 13 of the electric motor 20 and the output shaft 14 of the torque converter 30, are not mechanically connected, but can be rotated while keeping sliding with each other. In addition, the torque converter 30 is also provided with a lock-up clutch that connects the two under prescribed conditions so that no slippage occurs between the two rotating shafts. The connection and disconnection of the lock-up clutch is controlled by the control unit 70.

The transmission 100 is equipped with multiple gears, clutches, one-way clutches, brakes, etc., which can convert the torque and the number of revolutions of the output shaft 14 of the torque converter 30 by switching the gear ratio and transmit it to the output shaft 15 Structure. In this embodiment, a transmission that can realize five forward shift stages and one reverse shift stage is adopted. The gear stage of the transmission 100 is set by the control unit 70 according to the vehicle speed and the like. The driver manually manipulates the gear lever provided in the car and selects the shift position to change the range of gears used.

In the dual power vehicle of the present embodiment, the operation of the engine 10, the electric motor 20, the torque converter 30, the transmission 100, the auxiliary machine drive motor 80, and the like are controlled by the control unit 70 (refer to FIG. 1). The control unit 70 is a single-chip microcomputer equipped with a CPU, RAM, ROM, etc., and the CPU performs various control processes described later in accordance with a program recorded in the ROM. The control unit 70 is connected with various input and output signals for realizing the above-mentioned control. FIG. 3 is an explanatory diagram showing the wiring of input and output signals to the control unit 70. The signal input to the control unit 70 is shown on the left side of the figure, and the signal output from the control unit 70 is shown on the right side.

The signals input to the control unit 70 are signals from various switches and sensors. Among these signals, for example, there are fuel cell temperature, fuel cell remaining fuel amount, battery remaining capacity SOC, battery temperature, water temperature of engine 10, ignition switch, engine 10 revolutions, ABS computer, mist eliminator, air compressor The opening, stopping, vehicle speed, the oil temperature of the torque converter 30, the shift position, the opening and closing of the side brakes, the amount of pedal brake stepping, the temperature of the catalyst that purifies the exhaust of the engine 10, and the accelerator pedal The operation amount of 55 corresponds to the throttle opening, cam angle sensor, driving force source brake switch, resolver signal, etc. In addition to this, many signals are also input to the control unit 70, and their illustration is omitted here.

The signal output from the control unit 70 is a signal for controlling the engine 10, the electric motor 20, the torque converter 30, the transmission 100, and the like. Among these signals, for example, there are a signal for controlling an electronic throttle valve, an ignition signal for controlling the ignition cycle of the engine 10, a fuel injection signal for controlling fuel injection, a motor control signal for controlling the operation of the electric motor 20, and a control signal for a deceleration device. , The control signal of the ABS transmission device, the control signal of the power switch 84 of the electric motor 20, the control signal of the battery 50, the control signal of the fuel cell system 60, and so on. In addition to this, many signals are also output from the control unit 70, and their illustration is omitted here.

(2) General operation: The general operation of the dual-power vehicle of this embodiment will be described below. As described in FIG. 1 above, the dual-power vehicle of this embodiment includes an engine 10 and an electric motor 20 as power sources. The control unit 70 uses the two separately according to the traveling state of the vehicle, that is, the vehicle speed and torque during traveling. The separate use of the two is set in advance according to the conversion map and stored in the ROM in the control unit 70.

Fig. 4 is an explanatory diagram showing the relationship between the running state of the vehicle and the power source. The area MG in the figure is an area where the electric motor 20 is used as a power source for driving. The area outside the area MG is an area where the engine 10 is used as a power source (area EG). Hereinafter, the former is referred to as EV driving, and the latter is referred to as engine driving. According to the structure of FIG. 1, it is also possible to drive with both the engine 10 and the electric motor 20 as power sources, but in this embodiment, such a region is not set.

As shown in the figure, when the dual-power vehicle of this embodiment starts running with the ignition switch 88 turned on, it first starts in the EV running mode. In this area, the input clutch 18 is disconnected to drive. When the vehicle starting in the EV driving mode reaches the driving state near the boundary between the area MG and the area EG in the transition diagram of FIG. 4, the control unit 70 engages the input clutch 18 and starts the engine 10 at the same time. When the input clutch 18 is engaged, the engine 10 is driven by the electric motor 20 to rotate. When the number of revolutions of the engine 10 increases to a predetermined value, the control unit 70 causes fuel to be injected and ignited. After the engine 10 is started in this way, only the engine 10 is used as a power source to travel in the area EG. When starting to drive in this area, the control unit 70 turns off all the transistors of the drive circuits 51 and 52. As a result, the electric motor 20 is only idling.

The control unit 70 performs such a control for switching the power source according to the traveling state of the vehicle, and also performs processing for switching the gear stage of the transmission 100. The switching of the gear stage, like the switching of the power source, is performed according to a conversion map preset in accordance with the driving state of the vehicle. The shift map also varies with the shift position. FIG. 5 shows conversion diagrams corresponding to the D position, the 4 position, and the 3 position. As shown in this conversion diagram, the control unit 70 executes the switching of the gear stage so that the gear ratio decreases as the vehicle speed increases.

(3) Power output processing: The power output processing in the area MG will be described below. FIG. 5 is a flowchart of the power output processing routine in the area MG of the first embodiment. This is the processing executed when the vehicle is in the operating state, that is, when the ignition switch 88 is in the on state. When the ignition switch 88 is in the off state, the operation of the entire vehicle is stopped, so this processing is not executed. When this processing is started, the CPU inputs signals from various sensors and switches (step S100). Then, the CPU judges whether the fuel cell (FC: Fuel Cell) 60 is in a state capable of generating electricity (step S110).

The determination is made based on the fuel cell temperature input to the control unit 70 and the remaining fuel amount of the fuel cell. If it is determined that the fuel cell 60 is capable of generating electricity, the target output value to be output by the fuel cell 60 is set (step S120). This processing uses the remaining capacity SOC and the accelerator opening degree of the battery 50 in the signal input in step S100. In addition, the table stored in the ROM described later is also referred to, and the target output value of the fuel cell 60 is set based on these parameters. Here, the accelerator opening degree is a parameter related to the required power to the power supply device including the fuel cell 60 and the battery 50, and is determined by the operation amount of the accelerator pedal 55.

6 is an explanatory diagram showing the relationship between the remaining capacity SOC of the battery 50, the accelerator opening degree, and the target output value of the fuel cell 60 in the first embodiment. In addition, the required power of the power supply device corresponding to the accelerator opening degree is indicated by a thin line L. In this embodiment, the target output value of the fuel cell 60 is set based on the accelerator opening degree and the remaining capacity SOC of the battery 50. The line L1 shown by the solid line, the line L2 shown by the broken line, and the line L3 shown by the one-dot lock line, the remaining capacity SOC of the battery 50 is different from each other, and decreases in the order. These relationships are stored in the ROM in the control unit 70 in the form of a graph. In addition, in this embodiment, the target output value of the fuel cell 60 is set in three levels based on the remaining capacity SOC of the battery 50, but it may be set to more levels or be continuously changed.

In this embodiment, as shown in FIG. 6, the gradient of the amount of change in the target output value corresponding to the amount of change in the accelerator opening degree is set to not exceed a predetermined maximum gradient. This maximum value is a value at which the output of the fuel cell 60 can follow the target output value even if the accelerator opening degree changes abruptly.

In the area where the throttle opening is small (area X in the figure), set the target output value higher than the required power, and in the area where the throttle opening is large (area Y in the figure), set the target output value Power is lower than required. That is, the output of the fuel cell 60 is limited to the area A shown in the figure. The fuel cell 60 of this embodiment has a high power generation efficiency in the region A shown in the figure. Therefore, by setting the target output value in the above manner, the fuel cell 60 can be used with high efficiency.

For example, when the remaining capacity SOC of the battery 50 is in the normal state (line L1), if a small value P is input as the accelerator opening degree, the target value Dp1 higher than the required power Di is set. According to this setting, it is possible to output power from the fuel cell 60 that is greater than the required power. The surplus power among the power output from the fuel cell 60 charges the battery 50.

In addition, when the remaining capacity SOC of the battery 50 is in a low state (line L2), if the value P is still input as the accelerator opening, set a value higher than the target output value Dp1 when the remaining capacity SOC of the battery 50 is in the normal state. Target output value Dp2. According to this setting, the fuel cell 60 can output more power than normal. The surplus power among the power output from the fuel cell 60 charges the storage battery 50 whose remaining capacity SOC has been reduced.

In this embodiment, the lower the remaining capacity SOC of the battery 50, the higher the target output value of the fuel cell 60 is set. According to this setting, when the remaining capacity SOC of the battery 50 is low, the charging can be performed more quickly, and the remaining capacity SOC of the battery 50 can be restored more quickly.

When the target output value of the fuel cell 60 is set, the fuel cell 60 outputs electric power corresponding to the value (step S130 in FIG. 5). At the same time, the battery 50 is charged and discharged to compensate for the difference between the output of the fuel cell 60 and the required power corresponding to the accelerator opening (step S140). These controls are performed based on the control signal of the power switch 84 output from the control unit 70. That is, when the battery 50 needs to be charged and discharged, the connection between the battery 50, the electric motor 20, and the fuel cell 60 is switched by the changeover switch 84, and the charge and discharge corresponding to the voltage difference are performed.

In the foregoing, the output of electric power when the fuel cell 60 is in a power-generating state is explained. If it is determined in step S110 of FIG. 5 that the fuel cell 60 is in a state where power generation cannot be generated, it is determined whether the remaining capacity SOC of the battery 50 is greater than or equal to its lower control limit LoS% (step S150). If the remaining capacity SOC of the battery 50 is lower than LoS%, the engine 10 is started and power is output (step S160). When the remaining capacity SOC of the battery 50 is LoS% or more, the battery 50 is output as the main power source (step S170).

The above-mentioned processing is performed by sampling the accelerator opening degree and the remaining capacity SOC of the battery 50 at regular intervals.

Hereinafter, a specific control example of the first embodiment will be given. FIG. 7 is a time chart showing, as an example, the target output value of the fuel cell 60 corresponding to the accelerator opening degree, the actual output of the fuel cell 60, and the output of the battery 50 in the first embodiment.

From time 0 to t2, the throttle opening is 0. During this period, the target output value of the fuel cell 60, the output of the fuel cell 60, and the output of the battery 50 are all zero. On the other hand, when the ignition switch 88 is turned on at time t1, although the fuel cell 60 actually needs to be operated for warm-up, both the fuel cell 60 and the battery 50 are in a state capable of outputting.

Assume that the accelerator opening degree is increased sharply at time t2. Therefore, the target output value of the fuel cell 60 also sharply increases according to the graph (see FIG. 6). In addition, it can be seen from FIG. 6 that the target output value does not necessarily coincide with the required power. The target output value at time t2 is set to a value greater than the required power required for traveling. The output of the fuel cell 60 cannot follow the sharp increase in the target output value due to its low responsiveness, so it increases at the maximum slope. At this time, the battery 50 is made to output electric power to compensate for the insufficient output of the fuel cell 60. Therefore, the remaining capacity SOC of the battery 50 decreases.

It is assumed that the accelerator opening degree is gradually increased at time t2 to t4. Therefore, the target output value of the fuel cell 60 also gradually increases according to the graph. In addition, it can be seen from FIG. 6 that the rate of change of the target output value of the fuel cell 60 is smaller than the rate of change of the required power corresponding to the accelerator opening. It is assumed that the control unit 70 detects a decrease in the remaining capacity SOC of the battery 50 at time t3. Therefore, the target output value is increased to be greater than the normal target output value according to its decrease. The output of the fuel cell 60 increases at the maximum slope before reaching the target output value of the fuel cell 60 at time t3'. At time t3' to t4, since the rate of change of the target output value is smaller than the output responsiveness of the fuel cell 60 and thus can be tracked, the output of the fuel cell 60 increases with the target output value. Before the output of the fuel cell 60 reaches the target output value at time t3', the battery 50 is made to output electric power to compensate for the insufficient output of the fuel cell 60. Since the output of the fuel cell 60 after time t3' is greater than the required power, the battery 50 is charged with the surplus power. At time t3' to t4, since the required power can be output only with the output of the fuel cell 60, the battery 50 does not output.

Assume that the accelerator opening degree is sharply reduced at time t4. Therefore, the target output value of the fuel cell 60 also sharply decreases according to the graph. In addition, at time t4, the control unit 70 detects that the remaining capacity SOC of the storage battery 50 has been sufficiently charged, and therefore returns to the normal target output value. Since the rate of change of the target output value is smaller than the output responsiveness of the fuel cell and thus can be tracked, the output of the fuel cell 60 decreases with the target output value. Since only the output of the fuel cell 60 can output the required power corresponding to the accelerator opening degree, the battery 50 does not output.

After time t4, it is assumed that the accelerator opening degree is increased at time t4 to t5, decreased at time t5 to t6, and increased after time t6. During this period, the target output value of the fuel cell 60 also increases or decreases according to the graph at a rate of change smaller than the rate of change of the accelerator opening, so that the output of the fuel cell 60 increases or decreases following the target output value. Since only the output of the fuel cell 60 can output the required power corresponding to the accelerator opening degree, the battery 50 does not output.

In order to clarify the control effect of the first embodiment described above, the conventional control of the fuel cell 60 and the storage battery 50 is shown as a comparative example. FIG. 8 is a time chart showing, as an example, the target output value of the fuel cell 60 corresponding to the accelerator opening degree, the actual output of the fuel cell 60, and the output of the battery 50 of the comparative example. The throttle opening is the same as shown in Figure 7. The target output value of the fuel cell 60 of the comparative example is set to the same value as the required power corresponding to the accelerator opening degree.

From time 0 to t2, the throttle opening is 0. During this period, the target output value of the fuel cell 60, the output of the fuel cell 60, and the output of the battery 50 are all zero.

At time t2, the accelerator opening is increased sharply. Therefore, the target output value of the fuel cell 60 also sharply increases with the accelerator opening. The output of the fuel cell 60 cannot follow the sharp increase in the target output value due to its low responsiveness, so it increases at the maximum slope. At this time, the battery 50 is made to output electric power to compensate for the insufficient output of the fuel cell 60. Therefore, the remaining capacity SOC of the battery 50 decreases.

At time t2 to t4, the accelerator opening is gradually increased. Therefore, the target output value of the fuel cell 60 also gradually increases with the accelerator opening. The output of the fuel cell 60 increases at a maximum slope before reaching the target output value of the fuel cell 60 at time t3. Before the output of the fuel cell 60 reaches the target output value at time t3, the battery 50 is made to output electric power to compensate for the insufficient output of the fuel cell 60. At times t3 to t4, since the rate of change of the target output value is smaller than the output responsiveness of the fuel cell 60 and therefore tracking can be performed, the output of the fuel cell 60 increases in accordance with the target output value. At times t3 to t4, since the required electric power can be output only with the output of the fuel cell 60, the battery 50 does not output.

At time t4, the accelerator opening is sharply reduced. Therefore, the target output value of the fuel cell 60 also sharply decreases with the accelerator opening. At this time, the output of the fuel cell 60 can track the target output value, and thus decreases with the target output value. Since only the output of the fuel cell 60 can output the required power corresponding to the accelerator opening degree, the battery 50 does not output.

At time t4 to t5, the accelerator opening is increased. During this period, the target output value of the fuel cell 60 increases with the accelerator opening. Since the rate of change of the target output value of the fuel cell 60 is greater than that of the first embodiment, the output of the fuel cell 60 cannot follow the target output value, but increases at a maximum slope. The battery 50 outputs electric power to compensate for the insufficient output of the fuel cell 60. Therefore, the remaining capacity SOC of the battery 50 decreases.

At time t5 to t6, the accelerator opening is reduced. During this period, the target output value of the fuel cell 60 increases with the accelerator opening. The output of the fuel cell 60 still increases at the maximum slope before the time t5' when the target output value is reached, and decreases with the target output value after reaching the target output value. Before the time t5' when the output of the fuel cell 60 reaches the target output value, the battery 50 is made to output electric power to compensate for the insufficient output of the fuel cell 60. The required power corresponding to the opening degree, so the battery 50 no longer outputs.

After time t6, the accelerator opening is increased. During this period, the target output value of the fuel cell 60 increases with the accelerator opening. Since the rate of change of the target output value is smaller than the output responsiveness of the fuel cell, the output of the fuel cell 60 increases and decreases following the target output value. Since only the output of the fuel cell 60 can output the required power corresponding to the accelerator opening, the battery 50 does not output.

As described above, in the comparative example, the battery 50 can output electric power to compensate for the insufficient output of the fuel cell 60 as in the first embodiment, so the responsiveness can be ensured. However, since the target output value of the fuel cell 60 is set to the same value as the required electric power, when the throttle opening varies greatly, the output of the fuel cell 60 cannot track the target output value, and therefore it will not be possible to match the target output value. Corresponding to the stable control situation. In addition, since the target output value corresponding to the remaining capacity SOC of the battery 50 is not set, the remaining capacity SOC cannot be ensured. When the remaining capacity SOC falls below the predetermined value, charging will occur and the engine 10 has to be operated. Case.

On the other hand, according to the first embodiment, even when the throttle opening varies greatly, since the target output value of the fuel cell 60 varies less than the output responsiveness, the output of the fuel cell 60 can be stably controlled. As a result, not only can the output responsiveness corresponding to the accelerator opening degree be ensured, but also the fuel cell 60 can be effectively used as a power supply source. In addition, since the target output value corresponding to the remaining capacity SOC of the battery 50 is set, the battery 50 can be quickly charged with high efficiency. Therefore, the capacity of the battery 50 can be reduced, and the power supply device can be reduced in size and weight.

(4) Second embodiment: In the first embodiment, the remaining capacity SOC and the accelerator opening of the battery 50 are sampled at regular intervals, and the target output value of the fuel cell 60 is set at any time based on the sampling result. In the second embodiment, a case is shown in which the rate of change of the accelerator opening degree is calculated from the accelerator opening degree sampled at regular intervals, and the target output value setting process of the fuel cell 60 is changed based on the calculation result. The structure of the device is the same as that of the first embodiment. In addition, the flow of the power output processing routine other than the target output value setting processing of the fuel cell 60 is also the same.

FIG. 9 is a flowchart showing the target output value setting process of the fuel cell 60 in the second embodiment. When this processing is started, the CPU first reads the accelerator opening degree (step S200). Then, the rate of change r of the accelerator opening is calculated based on the accelerator opening degree read last time, the accelerator opening degree read this time, and the sampling time (step S210). The absolute value |r| of the rate of change of the accelerator opening degree is compared with the threshold value Rth of the rate of change previously stored in the ROM (step S220). If the absolute value |r| of the rate of change of the accelerator opening degree exceeds the threshold Rth, a new target output value is set according to the accelerator opening degree (step S230). The target output value set here is the target output value when the remaining capacity SOC of the battery 50 in the first embodiment shown in FIG. 6 is in a normal state. However, the graph (see FIG. 6) storing the relationship between the accelerator opening and the target output value of the fuel cell 60 can be set arbitrarily. If the absolute value of the rate of change of the throttle opening |r| is smaller than the threshold Rth, the new target output value is not set, but the original target output value before then is maintained. That is, when the rate of change of the accelerator opening degree is large, it is changed to a new target output value, and when the rate of change is small, control is performed that does not change the target output value at any time.

In addition, the threshold Rth can be arbitrarily set. For example, the threshold Rth may be a fixed value. In addition, it may be changed at any time according to the driver's judgment on the operating tendency of the accelerator pedal 55, and the past operating conditions of the fuel cell 60 and the battery 50. In addition, the threshold value Rth may be different when the rate of change r of the accelerator opening degree is positive and when it is negative.

Next, the remaining capacity SOC of the battery 50 is read (step S240), and it is determined whether the remaining capacity SOC is greater than or equal to the predetermined value LO% (step S250). If the remaining capacity SOC is greater than or equal to the predetermined value LO%, it is determined that the battery 50 has a sufficient remaining capacity SOC, and the process ends. If the remaining capacity SOC is lower than the predetermined value LO%, a correction value for increasing the target output value is set (step S260) so that the battery 50 can be charged with the output of the fuel cell 60. After the correction value is added, it is set as a new target output value (step S270).

In addition, the predetermined value LO can be set arbitrarily. However, if LO is set too high, the correction of the target output values of steps S260 and S270 will be frequently performed, and therefore, the operation of the fuel cell 60 may not be stable in some cases. On the other hand, if the LO is set too low, the storage battery 50 will be used more, which may prevent the fuel cell 60 from being used efficiently.

Hereinafter, a specific control example of the second embodiment will be given. 10 is a time chart showing, as an example, the target output value of the fuel cell 60 corresponding to the accelerator opening degree, the actual output of the fuel cell 60, and the output of the battery 50 in the second embodiment. The throttle opening is the same as shown in Figure 7.

From time 0 to t2, the throttle opening is 0. During this period, the target output value of the fuel cell 60, the output of the fuel cell 60, and the output of the battery 50 are all zero.

At time t2, the accelerator opening is increased sharply. At this time, it is assumed that the absolute value of the throttle opening change rate exceeds the threshold Rth. Therefore, the target output value of the fuel cell 60 also sharply increases with the accelerator opening. The output of the fuel cell 60 cannot follow the sharp increase in the target output value due to its low responsiveness, so it increases at the maximum slope. At this time, the battery 50 is made to output electric power to compensate for the insufficient output of the fuel cell 60.

At time t2 to t4, the accelerator opening is gradually increased. During this period, it is assumed that the absolute value of the rate of change of the accelerator opening is smaller than the threshold value Rth. The target output value of the fuel cell 60 is maintained at the value set at time t2. The output of the fuel cell 60 increases at the maximum slope before reaching the target output value at time t3. At times t3 to t4, a certain amount of electric power is output according to the target output value. The battery 50 is made to output electric power to compensate for the insufficient output of the fuel cell 60.

At time t4, the accelerator opening is sharply reduced. At this time, it is assumed that the absolute value of the throttle opening change rate exceeds the threshold Rth. Therefore, the target output value of the fuel cell 60 also sharply decreases with the accelerator opening. The output of the fuel cell 60 decreases following the target output value. Since only the output of the fuel cell 60 can output the required power corresponding to the accelerator opening degree, the battery 50 does not output.

At time t4 to t5, the accelerator opening is increased. During this period, it is assumed that the absolute value of the rate of change of the accelerator opening is smaller than the threshold value Rth. Then, the target output value of the fuel cell 60 is maintained at the value set at time t4. The fuel cell 60 outputs a certain amount of electric power based on the target output value. The battery 50 is made to output electric power to compensate for the insufficient output of the fuel cell 60.

At time t5 to t6, the accelerator opening is reduced. During this period, it is assumed that the absolute value of the rate of change of the accelerator opening is smaller than the threshold value Rth. Therefore, the target output value of the fuel cell 60 maintains the value at time t4 (or time t5) until time t5' when the control unit 70 detects that the remaining capacity SOC of the battery 50 is lower than LO%. The fuel cell 60 outputs according to the target output value before time t5'. The battery 50 is made to output electric power to compensate for the insufficient output of the fuel cell 60.

Assume that the control unit 70 detects that the remaining capacity SOC of the battery 50 is lower than LO% at time t5'. Therefore, at this time, although the accelerator opening is reduced, the target output value of the fuel cell 60 can be corrected to be higher so that the battery 50 can be quickly charged. The output of the fuel cell 60 cannot follow the increase in the target output value due to its low responsiveness, and therefore increases at the maximum slope.

After time t6, the accelerator opening is gradually increased. During this period, it is assumed that the absolute value of the rate of change of the throttle opening is smaller than the threshold value Rth. Therefore, the target output value of the fuel cell 60 is maintained at the value set at time t5'. The fuel cell 60 outputs a certain amount of electric power based on the target output value. Since only the output of the fuel cell 60 can output the required power corresponding to the accelerator opening degree, the battery 50 does not output. Since the output of the fuel cell 60 after the time t5' shown in the figure is greater than the required power, the battery 50 is charged with the surplus power. In addition, although not shown in the figure, when the accelerator opening degree is increased sharply and then slowly decreased, that is, when the absolute value of the accelerator opening degree change rate is less than the threshold value Rth, since the target output value of the fuel cell 60 does not decrease, Therefore, the battery 50 can still be charged.

In the second embodiment, the fuel cell 60 with low output responsiveness to the accelerator opening degree has reduced sensitivity to the accelerator opening degree, so that stable operation control of the fuel cell 60 can be performed. In addition, a battery 50 having a good output responsiveness to sudden changes in the accelerator opening degree is used. By adopting this structure, not only the output responsiveness corresponding to the accelerator opening degree can be ensured, but also the overcharging of the battery 50 can be suppressed and the fuel cell 60 can be effectively used as a power supply source.

(5) Third embodiment: The dual power vehicle of the third embodiment is equipped with a navigation system. Fig. 11 is a schematic configuration diagram of a dual power vehicle according to a third embodiment. The navigation system 90 is connected to the control unit 70, and inputs the route information for the vehicle to travel in the future to the control unit 70. The hardware structure other than this is the same as that of the first embodiment. In addition, in the first embodiment and the third embodiment, a part of the power output processing is different.

Fig. 12 is a flowchart of a power output processing routine of the third embodiment. When this processing is started, the CPU inputs signals from various sensors and switches (step S300). Then, the CPU determines whether the fuel cell 60 is in a state capable of generating electricity (step S310).

If the fuel cell 60 is in a power-generating state, the process of setting the target output value to be output by the fuel cell 60 is performed (step S320). This processing is the same as in the first embodiment. After the target output value of the fuel cell 60 is set, it is determined whether or not the vehicle is traveling using the navigation system 90 (step S330). Unless the navigation system 90 is used for traveling, the fuel cell 60 outputs electric power corresponding to the target output value as in the first embodiment (step S350). The storage battery 50 is charged and discharged to compensate for the difference between the output of the fuel cell 60 and the required power corresponding to the accelerator opening (step S360). When traveling using the navigation system 90, the target output value is subjected to correction processing for navigation system traveling.

In addition, it may be determined in step S330 that the navigation system 90 is not used for traveling in the case of a traffic jam or a stop due to a wait for a signal.

Fig. 13 is a flowchart of target output value correction processing for navigation system driving. When this processing is started, the CPU reads the route information from the navigation system 90 (step S400). The route information includes information about the slope of uphill or downhill, or highway information. Next, based on the route information, the required power for a predetermined time in the future is predicted (step S410). For example, when the CPU detects from the navigation system 90 that there is an upward slope ahead, it predicts the power required to turn on the upward slope. Then, the target output value for a predetermined time in the future is set based on the predicted future required power (step S420). Next, the target output is performed based on the future target output value, the target output value set in step S320 of FIG. 12, the target output value for a predetermined time in the future, and the output characteristics of the fuel cell 60 (the maximum slope that can be output). Value correction (step S430).

14 is a time chart showing, as an example, the target output value of the fuel cell 60 corresponding to the accelerator opening degree, the actual output of the fuel cell 60, and the output of the battery 50 in the third embodiment. The throttle opening is a certain value before time t2, and the required power is PW1. It becomes an upward slope at time t2 to t3, so it increases to PW2. Maintain a constant value from time t3 to t5. It becomes downhill at time t5 to t6, so it decreases to PW1. It is a constant value after time t6.

The control unit 70 can recognize that there is an upward slope before the time t2 near the upward slope based on the route information from the navigation system 90. Then, based on the current target output value PW1, the future target output value PW2, and the output characteristics of the fuel cell 60, the response time required to increase the output of the fuel cell 60 from PW1 to PW2 is calculated, and the response time is calculated. The target output value is increased to PW2 at time t1, thereby correcting the target output value. The fuel cell 60 can increase the output in advance based on the corrected target output value in order to prepare for future output increases. In FIG. 14, at time t1, the target output value of the fuel cell 60 is increased sharply from PW1 to PW2, but it may be gradually increased as the accelerator opening is approaching an upward slope so that the fuel cell 60 can output all the values. Electricity required.

In addition, the control unit 70 can recognize that there is a downhill ahead before the time t5 near the downhill based on the route information from the navigation system 90. Then, according to the current target output value PW2, the future target output value PW1, and the output characteristics of the fuel cell 60, the target output value is reduced to PW2 at time t4 to correct the target output value, and it can be recognized that although It consumes the power of the battery 50 but can be charged when going downhill. At times t4 to t6, since the output from the fuel cell 60 cannot satisfy the required power, the battery 50 outputs the insufficient portion.

In addition, in the above description, the case where the output of the fuel cell 60 is increased or decreased when going uphill and downhill is described, but for example, the same method can be used in the case of acceleration due to entering a highway, etc. Prepare for the increase in output.

In the foregoing, the power output when the fuel cell 60 is in a power-generating state has been described. If it is determined in step S310 of FIG. 12 that the fuel cell 60 is in a state where power generation cannot be generated, it is determined whether the remaining capacity SOC of the battery 50 is greater than or equal to its lower control limit LoS% (step S370). If the remaining capacity SOC of the battery 50 is lower than LoS%, the engine 10 is started and power is output (step S380). When the remaining capacity SOC of the battery 50 is LoS% or more, the battery 50 is output as the main power source (step S390).

As described above, according to the third embodiment, in the vehicle equipped with the navigation system 90, not only the output responsiveness corresponding to the accelerator opening degree can be ensured, but also the fuel cell 60 can be effectively used as a power supply source.

(6) Modifications:

As mentioned above, several embodiments of the present invention have been described, but the present invention does not limit the above-mentioned embodiments in any way, and various embodiments can be implemented without departing from the gist of the present invention. For example, the following modification examples may also be used.

In the first embodiment described above, the relationship between the remaining capacity SOC of the battery 50, the accelerator opening degree, and the target output value of the fuel cell 60 shown in FIG. 6 is stored in the form of a graph, but the remaining capacity SOC of the battery 50 may be The target output value of the fuel cell 60 is obtained by using the accelerator opening degree as a parameter.

In the second embodiment described above, it is determined whether or not to correct the target output value of the fuel cell 60 based on the rate of change of the accelerator opening. However, the fuel cell 60 may be adjusted based on the rate of change of the accelerator opening and the amount of change of the accelerator opening. The target output value is corrected. In this way, when the accelerator opening change rate is small but the accelerator opening change has exceeded the prescribed value, excessive charging and discharging of the battery 50 can be suppressed, and an appropriate target output value can be set.

In addition, in the above-mentioned second embodiment, the rate of change of the accelerator opening is calculated based on the accelerator opening sampled at certain intervals, but the rate of change of the accelerator opening may also be directly detected by a sensor.

In the above-mentioned embodiment, the case where the present invention is applied to a dual-power vehicle is exemplified, but it can also be applied to an electric vehicle that does not have an engine installed. Fig. 15 is a schematic configuration diagram of an electric vehicle. This electric vehicle is composed of a fuel cell 60B, a battery 50B, a control unit 70B, a changeover switch 84B, an inverter 52B, an electric motor 20B, an accelerator pedal 55B, a differential gear device 16B, and an axle 17B. In FIG. 15, only transmission paths of main signals, electric power, and power are shown, and the auxiliary machine driving device 82 and the transmission 100 shown in FIG. 1 are omitted.

In the above embodiment, the battery 50 is used as a chargeable and dischargeable power storage unit, but a power storage device such as a capacitor may also be used.

In the above-mentioned embodiment, a dual-power vehicle that can transmit the power of the engine 10 to the axle 17 is illustrated, that is, a parallel dual-power vehicle, but it can also be applied to a series dual-power vehicle.

In the above-mentioned embodiment, various control processes are realized by executing software by the CPU, but these processes can also be realized by hardware.

Industrial Applicability The present invention can be applied to the control of a power supply device using a fuel cell and a power storage unit as a power source.