JP2004192826A - Fuel cell system and vehicle mounting the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell system and a vehicle mounting the same capable of maintaining effect of a regenerative brake for a long time and securing a stable output state of a fuel cell. <P>SOLUTION: The vehicle mounting the fuel cell 3 controls an operation of storing regenerated energy generated at a traction motor 36 in a capacitor 32 and an operation of storing reaction gas in an accumulator 24 by compressing it with an air compressor 28 with the use of the regenerated energy. Therefore, the regenerated energy can be stored in the capacitor 32 as well as utilized for gas compression, and the effect of the regenerated brake can be maintained for a long time. Further, by supplying the compressed gas to the fuel cell 30, an electrochemical reaction at the fuel cell 30 is accelerated, and a stable output state can be maintained without apprehension of a gas shortage. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel cell system and a vehicle equipped with a fuel cell system.
[0002]
2. Description of the Related Art
2. Description of the Related Art Conventionally, for example, Patent Document 1 proposes a power supply device that uses a fuel cell and an electric double layer capacitor (hereinafter, capacitor) connected in parallel to a load as a fuel cell system. If the battery has been charged to near its rated capacity, the generated regenerative energy cannot be sufficiently stored in the capacitor, and the effect of the regenerative brake cannot be maintained for a long time. In addition, there is a problem in that it is not possible to cope with a case where the reaction gas is excessively required, and the gas becomes insufficient, and the voltage of the fuel cell is reduced, so that a stable output state cannot be secured. Also, for example, Patent Document 2 proposes a vehicle equipped with a fuel cell system in which a reaction gas supplied to a fuel cell using regenerative energy is stored in a gas tank as a gas pressure. In this case, the generated regenerative energy cannot be used to sufficiently accumulate the reaction gas in the gas tank, so that there is a problem that the regenerative braking cannot be maintained for a long period of time. In addition, Patent Literature 2 describes an auxiliary secondary battery, but it is used for starting a reaction gas compression system and is not used for storing regenerative energy.
[0003]
[Patent Document 1]
JP-A-2002-216818
[Patent Document 2]
JP-A-6-203846
[0004]
SUMMARY An advantage of some aspects of the invention is to provide a fuel cell system and a vehicle equipped with a fuel cell system that can maintain the regenerative braking effect for a long period of time. Another object of the present invention is to provide a fuel cell system and a vehicle equipped with a fuel cell system capable of ensuring a stable output state of the fuel cell.
[0005]
[Means for Solving the Problems and Their Functions and Effects]
In order to achieve at least a part of the above objects, a first aspect of the present invention is to supply power to a load from at least one of a fuel cell that generates power by an electrochemical reaction of a reaction gas and a power storage unit that stores electric energy. A fuel cell system,
Gas compression means for compressing the reaction gas,
Pressure accumulating means for storing the gas compressed by the gas compressing means in a state in which the gas can be supplied to the fuel cell;
Regenerative control means for controlling an operation of storing regenerative energy generated in the load in the power storage means and an operation of compressing the reaction gas by the gas compression means using the regenerative energy and accumulating the reaction gas in the pressure accumulator means;
It is provided with.
[0006]
In this fuel cell system, the operation of storing the regenerative energy generated at the load in the power storage means and the operation of compressing the reaction gas by the gas compression means using the regenerative energy and storing the pressure in the pressure storage means are controlled. Therefore, the regenerative energy can be stored in the power storage means or used for gas compression, so that the effect of the regenerative brake can be maintained for a long time. Further, by supplying the compressed gas to the fuel cell, an electrochemical reaction in the fuel cell is promoted, and a stable output state can be secured without fear of running out of gas.
[0007]
Here, the reaction gas includes a fuel gas and an oxidizing gas, and the gas compressing means may compress the fuel gas, may compress the oxidizing gas, or may compress both gases. When the gas compression means compresses the fuel gas, the compressed fuel gas is stored, when the oxidizing gas is compressed, the compressed oxidizing gas is stored, and when both gases are compressed, each compressed gas is stored separately. May be stored.
[0008]
In the fuel cell system of the present invention, determining means for determining whether or not the time change rate of the supply amount of the reaction gas to the fuel cell falls within a predetermined increasing area; and The fuel cell may further include a gas supply control unit that supplies the gas stored in the pressure accumulating unit to the fuel cell when it is determined that the gas enters. By doing so, when the rate of change of the supply amount of the reaction gas with time changes suddenly, it is possible to prevent the gas shortage by supplying the accumulated reaction gas to the fuel cell, and to stably supply the power from the fuel cell to the load. Can be supplied.
[0009]
In the fuel cell system of the present invention, the regenerative control unit stores the regenerative energy in the power storage unit rather than using the regenerative energy to compress the reaction gas by the gas compression unit and accumulate the pressure in the accumulator unit. The operation of storing power may be performed with priority. In this case, the regenerative energy is preferentially stored in the power storage means and supplied to the load, which contributes to improving fuel efficiency.
[0010]
In the fuel cell system of the present invention, the regenerative control unit compresses the reaction gas by the gas compression unit using the regenerative energy to accumulate the pressure in the accumulator, and stores the regenerative energy in the power storage unit. The operation of storing power may be performed in parallel. By doing so, the regenerative energy is stored in the power storage means and supplied to the load, which helps to improve fuel efficiency. In addition, the reaction gas can be stored in pressure in case of a sudden increase in the supply of the reaction gas to the fuel cell. it can.
[0011]
In the fuel cell system in which the power storage unit, the fuel cell, and the load are connected in parallel, a shutoff unit that cuts off / non-blocks the connection between the power storage unit and the fuel cell, and a voltage of the power storage unit is predetermined. The fuel cell may further include cut-off control means for cutting off the connection between the power storage means and the fuel cell by the cut-off means when the operating voltage of the fuel cell deviates. With this configuration, when the allowable operating voltage is deviated, the fuel cell is disconnected from the power storage means, thereby protecting the fuel cell and preventing a reduction in fuel efficiency. For example, if the voltage is higher than the allowable operating voltage range, a voltage exceeding the open voltage of the fuel cell may be applied between both electrodes of the fuel cell. In the case of (1), since an excessive electrochemical reaction is required for the fuel cell, the fuel cell is disconnected from the power storage means.
[0012]
A fuel cell system in which the power storage means, the fuel cell, and the load are connected in parallel, a shutoff means for shutting off / non-interruption of the connection between the power storage means and the fuel cell, and the fuel cell being connected to the fuel cell by the shutoff means. When the connection to the power storage means is interrupted and power is supplied to the load only from the power storage means and the voltage of the power storage means enters a predetermined low voltage region, the power storage means And disconnection control means for supplying power from the fuel cell to the load while disconnecting the connection with the fuel cell and supplying the reaction gas compressed from the pressure accumulating means to the fuel cell. Good. When the connection between the power storage means and the fuel cell is not interrupted, if the supply amount of the reaction gas of the fuel cell is insufficient with respect to the voltage of the power storage means, the voltage of the fuel cell will further decrease. By supplying gas to the fuel cell, gas shortage can be avoided, and voltage drop of the fuel cell due to gas shortage can be prevented. Therefore, even when the power storage means and the fuel cell are connected, power can be stably supplied from the fuel cell to the load. Note that the cutoff control means is configured to disconnect the connection between the power storage means and the fuel cell by the cutoff means and supply power from the fuel cell to the load. Control may be performed so that the reaction gas compressed from the accumulator is supplied to the fuel cell when entering the increase region.
[0013]
A fuel cell system including a shut-off unit and a shut-off control unit stops the operation of the fuel cell when the connection between the fuel cell and the power storage unit is cut off by the shut-off unit, and the fuel cell and the power storage unit A fuel cell operation control means for operating the fuel cell when the connection to the fuel cell is not interrupted. In this way, it is possible to save the power of the auxiliary equipment required for operating the fuel cell, and to improve the energy efficiency of the entire fuel cell system.
[0014]
In the fuel cell system according to the present invention, the power storage means may be a capacitor. A capacitor has higher charge / discharge efficiency than a secondary battery, but the rated capacity of the capacitor may be smaller than that of the secondary battery even if the size of the secondary battery and the capacitor are the same, In such a case, it is highly necessary that the regenerative energy exceeding the rated capacity of the capacitor be compressed by the gas compressing means by the gas compressing means and accumulated in the pressure accumulating means.
[0015]
According to a second aspect of the present invention, there is provided a vehicle equipped with the above-described fuel cell system, wherein the load is a running motor. According to this vehicle equipped with a fuel cell system, the same effects as those of the above-described fuel cell system can be obtained.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory diagram illustrating a fuel cell system according to an embodiment of the present invention.
[0017]
The fuel cell system 20 includes a fuel cell 30 that generates power using hydrogen gas as a fuel gas supplied from a hydrogen high-pressure tank 22 and oxygen in the air supplied from an air compressor 28 or an accumulator 24, and a circuit breaker for the fuel cell 30. It includes a capacitor 32 connected in parallel via 56, an inverter 34 for converting DC power into AC power suitable for driving the driving motor 36, and a controller 70 for controlling running of the entire system and the vehicle. As described above, in the fuel cell system 20, the fuel cell 30, the capacitor 32, and the traveling motor 36 are connected in parallel, and power is supplied from the fuel cell 30 to the traveling motor 36, and the traveling motor 36 is supplied from the capacitor 32. Power supply. Further, the fuel cell system 20 has three states: a state in which the air compressor 28 communicates with the fuel cell 30, a state in which the air compressor 28 communicates with the accumulator 24, and a state in which the accumulator 24 communicates with the fuel cell 30. A switching valve 50 for switching the state is provided. When the air compressor 28 and the fuel cell 30 are in communication with each other by the switching valve 50, air can be pumped from the air compressor 28 to the fuel cell 30. In the state where the air compressor 28 and the accumulator 24 are in communication, the air compressor can be used. Air can be pumped from the accumulator 24 to the accumulator 24, and when the accumulator 24 is in communication with the fuel cell 30, air can be pumped from the accumulator 24 to the fuel cell 30. The hydrogen discharged from the fuel cell 30 without being reacted is circulated again by the gas circulation pump 26 that supplies the hydrogen to the fuel cell 30 again.
[0018]
Although not shown, the fuel cell 30 is configured by a fuel cell stack in which a plurality of electrolyte membranes, a single cell including an anode electrode and a cathode electrode sandwiched between the electrolyte membranes, and a separator forming a partition between cells are stacked. In addition, power is generated with the generation of water by an electrochemical reaction between the hydrogen gas supplied to the anode electrode and the air supplied to the cathode electrode through a gas flow path formed in the separator. Although not shown, a circulation path through which a cooling medium (for example, cooling water) can circulate is formed in the fuel cell 30, and the temperature inside the fuel cell 30 is adjusted to an appropriate temperature by circulating the cooling medium in the circulation path. (For example, 65 ° C. to 85 ° C.).
[0019]
A flow control valve (not shown) for adjusting the flow rate of the exhaust gas is attached to the exhaust gas (oxygen system) discharged from the fuel cell 30, and the actuator of the flow control valve is driven to adjust the flow rate of the exhaust gas. By doing so, the pressure inside the fuel cell 30 can be adjusted.
[0020]
The traveling motor 36 is configured as, for example, a well-known synchronous generator motor that functions as a motor and also functions as a generator, and has an output shaft 39 connected to the wheels 12 via a differential gear 14 on a rotation shaft thereof. Are linked. Therefore, the power output from the traveling motor 36 is transmitted to the wheels 12 via the differential gear 14, and the propulsion of the vehicle is obtained.
[0021]
1 indicates that the output terminal of the inverter 92 and the input terminal of the air compressor 28 are connected. AC power to the built-in motor of the air compressor 28 is supplied by an inverter 92 that converts DC current and DC voltage from the fuel cell 30 or the capacitor 32 into AC power suitable for driving the air compressor 28. The DC power to the auxiliary equipment such as the switching valve 50 and the circuit breaker 56 adjusts the DC current and DC voltage from the fuel cell 30 or the capacitor 32 by the DC / DC converter 54, and stores the adjusted DC power. It is supplied by the next battery 60.
[0022]
The controller 70 is configured as a microprocessor centering on the CPU 72 as a controller for controlling the fuel cell system 20 and for controlling the running of the vehicle equipped with the fuel cell system 20, and stores a processing program and the like. A ROM 74, a RAM 76 for temporarily storing data, and an input / output port (not shown) are provided. The controller 70 includes a power supply voltage Vp from a voltage sensor 52 attached in parallel between the capacitor 32 and the inverter 34, a shift position from a shift position sensor 82 for detecting the position of the shift lever 81, An accelerator opening AP from an accelerator pedal position sensor 84 for detecting the amount of depression, a brake opening BP from a brake pedal position sensor 86 for detecting the amount of depression of the brake pedal 85, and a vehicle speed sensor 88 for detecting the traveling speed of the vehicle. The vehicle speed V and the like are input via the input port. Further, from the controller 70, a drive signal to the gas circulation pump 26, a drive signal to the air compressor 28, a switching signal to the inverters 34 and 92, a DC power conversion signal to the DC / DC converter 54, and a And a switching signal to the switching valve 50 are output via the output port.
[0023]
The ROM 74 obtains, in addition to the processing program, the relationship among the accelerator opening AP from the accelerator pedal position sensor 84, the brake opening BP from the brake pedal position sensor 86, the vehicle speed V from the vehicle speed sensor 88, and the required power Po. An operating point for determining whether the driving state of the driving motor 36 is a driving state or a driving state of regenerative control based on the relationship between the accelerator opening AP, the brake opening BP, and the vehicle speed V is stored. The ROM 74 also stores a map that defines the relationship between the output power of the fuel cell 30 and the amount of reactant gas supplied.
[0024]
When driving the traveling motor 36 by supplying electric power from the fuel cell 30, the controller 70 controls the output shaft 39 based on the accelerator opening AP from the accelerator pedal position sensor 84 and the vehicle speed V from the vehicle speed sensor 88. The required power Po is derived from the map of the ROM 74, the current value of the fuel cell 30 is obtained from the current-voltage characteristic of the fuel cell 30 based on the required power Po, and the reaction of the fuel cell 30 corresponding to the current value is performed. By deriving the gas supply amount from the map of the ROM 74, the reaction gas supply amount to the fuel cell 30 is controlled.
[0025]
Next, the operation of the fuel cell system 20 of the present embodiment will be described. FIG. 2 is a flowchart of the main control of the fuel cell system 20, and this process is read out every several msec and repeatedly executed. FIG. 3 is an explanatory diagram illustrating a power storage transition of power with time of the capacitor 32.
[0026]
When the main control process is executed, the CPU 72 of the controller 70 calculates the accelerator opening AP from the accelerator pedal position sensor 84, the brake opening BP from the brake pedal position sensor 86, and the vehicle speed V from the vehicle speed sensor 88. Reading (step S100), it is determined whether to perform drive control or regenerative control based on the read accelerator opening AP, brake opening BP, and vehicle speed V (step S110). When regenerative control is performed (for example, when the brake pedal 85 is depressed). When the brake opening BP exceeds a predetermined opening or when the accelerator pedal opening AP is zero and the vehicle speed V exceeds a predetermined speed, such as when the vehicle is running downhill, the circuit breaker 56 controls the capacitor 32 and the fuel cell 30. Is disconnected (step S120), the driving motor 36 is set to the power generation state, and the voltage sensor 5 Supply voltage measured by Vp (voltage of the capacitor 32) is equal to or smaller than a predetermined upper limit voltage Vmax (step S130). When Vp is smaller than the predetermined upper limit voltage Vmax, this process ends. Here, when Vp is smaller than the upper limit voltage Vmax (see the hatched area in FIG. 3), the connection between the fuel cell 30 and the capacitor 32 is cut off by the circuit breaker 56, so that the electric power generated from the traveling motor 36 Is stored. On the other hand, when the power supply voltage Vp is equal to or higher than the predetermined voltage Vmax in step S130, the drive signal to the air compressor 28 is turned on to operate the air compressor 28, and the switching valve 50 switches the air compressor 28 to the state where the accumulator 24 is communicated. (Step S140), the electric power generated from the traveling motor 36 is supplied to the air compressor 28 to accumulate the air in the accumulator 24 (Step S150), and this processing ends. On the other hand, when it is determined in step S110 that the vehicle is in the traveling state in which the driving of the traveling motor 36 is controlled, the required power Po is calculated based on the accelerator opening AP and the vehicle speed V read in step S100, and the traveling motor 36 is activated. The process proceeds to a driving routine (step S160), and after the process ends, the main control process ends.
[0027]
Subsequently, a case will be described in which the driving motor 36 of the vehicle is drive-controlled using the electric energy stored in the capacitor 32. This control is executed as one of the drive controls (step S160) of the traveling motor 36 of the main control. Here, for convenience of explanation, the connection to the fuel cell 30 is cut off by the circuit breaker 56, and the capacitor The following description is based on the premise that the vehicle travels using only the electric energy stored in the battery 32.
[0028]
FIG. 4 is a flowchart showing a motor drive control routine at that time. When this routine is executed, CPU 72 of controller 70 reads power supply voltage (voltage of capacitor 32) Vp detected by voltage sensor 52 (step S200), and determines whether power supply voltage Vp is higher than predetermined lower limit voltage Vmin. It is determined whether or not it is (step S210). FIG. 5 is a graph showing how the output voltage of the capacitor 32 not connected to the fuel cell 30 changes over time. When the power supply voltage Vp is greater than Vmin in step S210, the drive control of the traveling motor 36 is performed using only the electric energy stored in the capacitor 32 while the connection between the fuel cell 30 and the capacitor 32 is cut off by the circuit breaker 56. (Step S270), this routine ends.
[0029]
On the other hand, when the power supply voltage Vp is equal to or lower than Vmin in step S210, the connection between the fuel cell 30 and the capacitor 32 is not interrupted by the circuit breaker 56 (step S220). FIG. 6 is a graph showing current-voltage characteristics of the fuel cell 30. The fuel cell 30 connected to the capacitor 32 of the power supply voltage Vp is required to output a current corresponding to the power supply voltage Vp. For this reason, the controller 70 reads the reaction gas supply amounts (hydrogen supply amount Qh and air supply amount Qa) such that an electrochemical reaction commensurate with the current is read from the map stored in the ROM 74 and stores it in a predetermined area of the RAM 76 ( Step S230). Here, even if the current hydrogen supply amount Qh suddenly increases as compared with the previous time, the hydrogen can be promptly dealt with because the hydrogen is supplied from the hydrogen high-pressure tank 22, but if the air supply amount Qa increases rapidly, the air compressor Since the physique of 28 is not so large for the convenience of mounting on a vehicle, it is not possible to respond quickly. For this reason, the controller 70 calculates the difference ΔQa between the previous air supply amount Qa and the current air supply amount Qa, and determines whether ΔQa has exceeded the threshold value C, that is, the previous time so that the capacity of the air compressor 28 cannot quickly respond. In comparison, it is determined whether or not the current air supply amount Qa has increased rapidly (step S240). This routine is executed as one of the drive controls of the traveling motor 36 of the main control (step S160). Since the time interval between the previous time and the current time is several milliseconds, ΔQa corresponds to the time change rate. When ΔQa exceeds the threshold value C in step S240, the switching valve 50 is switched to a state in which the fuel cell 30 communicates with the accumulator 24 (step S250) because the capacity of the air compressor 28 cannot cope quickly. End the routine. In the subsequent motor drive control, a routine (not shown) for controlling the traveling motor 36 while operating the fuel cell 30 is executed instead of this routine, but for a while, the cathode electrode of the fuel cell 30 is controlled. The air is pressure-fed from the accumulator 24, and thereafter, at an appropriate timing (for example, after a lapse of a predetermined time or when the rotation speed of the air compressor 28 reaches the current air gas supply amount Qa), the switching valve 50 is set to the fuel cell 30. The air compressor 28 is switched to a state in which the air compressor 28 communicates with the air compressor 28 so that air is pumped from the air compressor 28 to the cathode electrode of the fuel cell 30.
[0030]
On the other hand, when ΔQa does not exceed the threshold value C in step S240, the switching valve 50 is switched to a state in which the fuel cell 30 communicates with the air compressor 28 because the capacity of the air compressor 28 can promptly respond (step S260). This routine ends. In executing this routine, it was assumed that the connection between the capacitor 32 and the fuel cell 30 was cut off by the circuit breaker 56, and the vehicle was running using only the electric energy stored in the capacitor 32. Occasionally, the operation of the accessories (including the air compressor 28) of the fuel cell 30 is suspended, and the operation of these accessories is restarted when the capacitor 32 and the fuel cell 30 are connected by the circuit breaker 56. Therefore, immediately after the operation is resumed, ΔQa generally exceeds the threshold value C.
[0031]
According to the present embodiment described above, the operation of storing the regenerative energy generated by the traveling motor 36 in the capacitor 32 and the operation of using the regenerative energy to compress the reaction gas by the air compressor 28 and accumulate the pressure in the accumulator 24. By controlling the regenerative braking, the regenerative energy can be stored in the capacitor 32 or gas can be compressed and stored in the accumulator 24, so that the regenerative braking effect can be maintained for a long time. Further, by supplying the compressed gas stored in the accumulator 24 to the fuel cell 30, the electrochemical reaction in the fuel cell 30 is promoted, and a stable output state can be secured without fear of running out of gas.
[0032]
Also, the regenerative energy is preferentially stored in the capacitor 32, which contributes to improved fuel efficiency.
[0033]
Further, when the connection between the fuel cell 30 and the capacitor 32 is not cut off and the air supply amount of the fuel cell 30 is insufficient with respect to the voltage of the capacitor 32, the voltage of the fuel cell further decreases. By supplying the air stored in the fuel cell 24 to the fuel cell 30, gas shortage can be avoided, and voltage drop of the fuel cell 30 due to gas shortage can be prevented.
[0034]
Further, when the connection between the fuel cell 30 and the capacitor 32 is changed from the cut-off state to the non-cut-off state by the circuit breaker 56, the time of the air supply amount to the fuel cell 30 when the fuel cell 30 supplies the power to the traveling motor 36. When the change rate ΔQa exceeds the threshold value C, that is, when the capacity of the air compressor 28 is exceeded, the air accumulated in the accumulator 24 is supplied to the fuel cell 30, so that a gas shortage can be avoided. Note that even when the power of the fuel cell 30 is supplied to the traveling motor 36, when the accelerator opening AP sharply increases, the air supply amount Qa sharply increases and ΔQa exceeds the threshold C. Therefore, at that time, the air stored in the accumulator 24 is similarly supplied to the fuel cell 30 to avoid gas shortage.
[0035]
Further, when the connection between the fuel cell 30 and the capacitor 32 is interrupted by the circuit breaker 56, the controller 70 suspends the operation of the auxiliary equipment of the fuel cell 30, and the connection between the fuel cell 30 and the capacitor 32 is interrupted. When the fuel cell 30 is not operating, the intermittent operation of operating the auxiliary equipment of the fuel cell 30 is performed, so that the power of the auxiliary equipment required for operating the fuel cell 30 can be saved, and the energy efficiency of the entire fuel cell system can be improved. it can.
[0036]
It should be noted that the present invention is not limited to the above-described embodiment at all, and it goes without saying that the present invention can be implemented in various modes as long as it belongs to the technical scope of the present invention.
[0037]
In the above-described embodiment, the regenerative energy generated by the traveling motor 36 is controlled to be preferentially stored in the capacitor 32. However, the reaction gas is compressed by the air compressor 28 using the regenerative energy, and the accumulator 24 is used. And the operation of storing regenerative energy in the capacitor 32 may be performed in parallel. In this way, the regenerative energy is stored in the capacitor 32 and supplied to the traveling motor 36, which helps to improve fuel efficiency, and accumulates the reaction gas in preparation for a sudden increase in the supply of the reaction gas to the fuel cell 30. You can keep it.
[0038]
In the above-described embodiment, the allowable operating voltage of the fuel cell 30 is set in advance, and the connection between the fuel cell 30 and the capacitor 32 is cut off when the voltage of the fuel cell 30 deviates from the allowable operating voltage. The protection of the fuel cell 30 and the prevention of reduction in fuel efficiency may be achieved. FIG. 7 is an explanatory diagram illustrating a relationship between the output current and the output voltage when the operation allowable voltage of the fuel cell is set. As shown in FIG. 7, when the voltage is higher than the allowable operating voltage range, the fuel efficiency may deteriorate or a voltage exceeding the open voltage of the fuel cell 30 may be applied between both electrodes of the fuel cell. When the voltage is lower than the allowable operating voltage range, an excessive electrochemical reaction is required for the fuel cell 30, so that the fuel cell 30 is disconnected from the capacitor 32. Thereby, the fuel cell 30 can be protected.
[0039]
Further, in the above-described embodiment, even if the supply amount Qh of hydrogen is suddenly increased by adopting the hydrogen high-pressure tank 22, it is possible to respond quickly even if the supply amount Qh of hydrogen is rapidly increased. In the case where a configuration that cannot cope with the above problem is adopted, the accumulator for accumulating hydrogen, the hydrogen supply pump and the anode electrode of the fuel cell 30 are connected via a three-way switching valve, and the hydrogen accumulator is supplied by the hydrogen supply pump using regenerative energy. Compressed hydrogen may be stored in the accumulator, and the compressed hydrogen of the hydrogen accumulator may be supplied to the anode electrode of the fuel cell 30 to avoid gas shortage when the time change rate ΔQh of the hydrogen supply amount exceeds a threshold.
[0040]
Furthermore, in the above-described embodiment, the fuel cell system 20 is operated intermittently, but may be continuously operated without intermittently operating.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing a vehicle equipped with a fuel cell.
FIG. 2 is a flowchart illustrating main control processing.
FIG. 3 is an explanatory diagram showing a transition of power storage with time of a capacitor.
FIG. 4 is a flowchart illustrating a drive control process.
FIG. 5 is an explanatory diagram showing an output voltage of a capacitor.
FIG. 6 is an explanatory diagram showing an output current and an output voltage of a fuel cell.
FIG. 7 is an explanatory diagram showing an operation allowable voltage.
[Explanation of symbols]
12 wheels, 14 differential gear, 20 fuel cell system, 22 hydrogen high pressure tank, 24 accumulator, 26 pump, 28 air compressor, 30 fuel cell, 32 capacitor 34 inverter, 36 motor, 39 output shaft, 50 switching valve, 52 voltage sensor , 54 DC / DC converter, 56 circuit breaker, 60 secondary battery, 70 controller, 72 CPU, 74 ROM, 76 RAM, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor, 85 brake pedal , 86 brake pedal position sensor, 88 vehicle speed sensor, 92 inverter.

Claims (9)

A fuel cell system that supplies power to a load from at least one of a fuel cell that generates power by an electrochemical reaction of a reaction gas and a power storage unit that stores electric energy,
Gas compression means for compressing the reaction gas,
Pressure accumulating means for storing the gas compressed by the gas compressing means in a state in which the gas can be supplied to the fuel cell;
Regenerative control means for controlling an operation of storing regenerative energy generated in the load in the power storage means and an operation of compressing the reaction gas by the gas compression means using the regenerative energy and accumulating the reaction gas in the pressure accumulator means; A fuel cell system comprising: The fuel cell system according to claim 1, wherein
Determining means for determining whether or not the time change ratio of the supply amount of the reaction gas to the fuel cell falls within a predetermined increase region;
A fuel cell system comprising: gas supply control means for supplying the gas stored in the pressure accumulating means to the fuel cell when it is determined by the determining means to enter the increase region. The regenerative control unit gives priority to an operation of storing the regenerative energy in the power storage unit over an operation of compressing the reaction gas by the gas compression unit using the regenerative energy and accumulating the reaction gas in the accumulator unit. The fuel cell system according to claim 1, wherein the fuel cell system is operated. The regenerative control unit performs an operation of compressing the reaction gas by the gas compression unit using the regenerative energy and accumulating the reaction gas in the accumulator, and an operation of storing the regenerative energy in the accumulator in parallel. Item 3. The fuel cell system according to Item 1 or 2. The fuel cell system according to any one of claims 1 to 4, wherein the power storage unit, the fuel cell, and the load are connected in parallel.
Blocking means for blocking / non-blocking the connection between the power storage means and the fuel cell;
A fuel cell system comprising: shutoff control means for interrupting connection between the power storage means and the fuel cell by the shutoff means when the voltage of the power storage means deviates from a predetermined allowable operating voltage of the fuel cell. The fuel cell system according to any one of claims 1 to 4, wherein the power storage unit, the fuel cell, and the load are connected in parallel.
Blocking means for blocking / non-blocking the connection between the power storage means and the fuel cell;
When the connection between the fuel cell and the power storage means is interrupted by the interrupting means and power is supplied to the load only from the power storage means, and the voltage of the power storage means enters a predetermined low voltage region. Shutting off the connection between the power storage means and the fuel cell by the interrupting means, supplying power from the fuel cell to the load, and supplying the reaction gas compressed from the pressure accumulating means to the fuel cell. A fuel cell system comprising control means. The fuel cell system according to claim 5, wherein:
The operation of the fuel cell is stopped when the connection between the fuel cell and the power storage means is interrupted by the interrupting means, and the operation of the fuel cell is stopped when the connection between the fuel cell and the power storage means is not interrupted. A fuel cell system comprising a fuel cell operation control means for performing the following. The fuel cell system according to claim 1, wherein the power storage unit is a capacitor. A vehicle equipped with the fuel cell system according to any one of claims 1 to 8, wherein the load is a running motor.

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