JP2007250359A - Power supply unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-reliability power supply unit using the fuel cell for an auxiliary power supply, which detects any fault of a fuel cell. <P>SOLUTION: The power supply unit determines whether a fuel cell 10 is faulty by generating power using the fuel cell 10 under a predetermined condition after supplying hydrogen to the fuel cell 10, under the normal condition of a main power supply 1 and under the predetermined condition. The power supply unit determines whether the fuel cell 10 is faulty by monitoring the normal power generation capability while operating the fuel cell 10 actually. This assures the power generation using the fuel cell 10 even in the event of fault in the main power supply 1, resulting in the achieved extremely high-reliability power supply unit. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power supply apparatus that continuously supplies power to a load in response to an abnormality of a main power supply.

  Conventionally, when an abnormality occurs in the main power source (for example, AC power source) due to a power failure or the like, power is continuously supplied to an electrical load (hereinafter abbreviated as a load) such as an emergency light or a computer system that handles important data. Therefore, a stationary power supply device called an uninterruptible power supply system is commercially available. This makes it possible to ensure safety in the dark and to prevent economic loss due to data loss. Especially with the remarkable spread of computers in recent years, the importance of the uninterruptible power supply system for the latter has become extremely large. .

  In recent years, the development of fuel-efficient and low-pollution hybrid vehicles and idling stop vehicles has been rapidly progressing. In both cases, vehicle braking energy is regenerated and stored in the power storage unit, and supplied to vehicle drive motors and starter motors. This effectively utilizes the braking energy that has been discarded. Various proposals have been made for such braking of vehicles from conventional mechanical hydraulic control to electrical hydraulic control.

  However, generally, if the power source (battery) for electrically controlling the hydraulic pressure of the vehicle cannot supply power for some reason, there is a possibility that the vehicle cannot be braked. Also, for idling stop vehicles, if the power supplied from the battery to the loads of various electrical components is cut off during idling stop, there is a possibility that loads indispensable for safety such as lights at night will stop. is there.

  Therefore, for example, an emergency power backup unit that supplies driving power to an important load such as an electrical hydraulic control unit in the event of a battery by installing a large-capacity capacitor as an auxiliary power source separately from the battery is proposed. Has been.

  As described above, in recent years, a power supply device represented by a stationary uninterruptible power supply system and an emergency power backup unit for automobiles has come to be regarded as extremely important.

  As such a power supply device, an example of a stationary uninterruptible power supply system as shown in Patent Document 1 will be described. FIG. 10 is a block diagram of a conventional power supply device. A portion indicated by a thick line indicates a power system wiring, a portion indicated by a thin line indicates a control system wiring, and a portion indicated by a dotted arrow indicates a pipe.

  In FIG. 10, a main power source 1 is composed of an AC power source 2 and a rectifying device 3, and generates a DC power source. This is supplied to the load 4.

  Normally, power is supplied as described above. However, when a power failure occurs, the power failure detection unit 6 incorporated in the auxiliary power source 5 indicates that a power failure has occurred. ). Alternatively, since the power supply may be interrupted due to a failure of the rectifier 3, the rectifier failure detector 8 notifies the controller 7 of the failure of the rectifier 3 in this case.

  In any case, when the power supply to the load 4 is cut off, the power is instantaneously supplied from the auxiliary power source 5. Specifically, since the power storage unit 9 composed of a secondary battery built in the auxiliary power supply 5 is connected to the output of the rectifier 3, power is supplied from the power storage unit 9 to the load 4. Thereby, the load 4 can be used continuously.

  However, since the power storage unit 9 is composed of a secondary battery, the power supply to the load 4 is stopped if the remaining power is exhausted. In order to reduce this possibility, a large number of secondary batteries may be used, but in this case, an increase in the size of the entire power supply device is inevitable.

  In view of this, a power supply device has been proposed in which a fuel cell 10 is used in addition to the power storage unit 9. As a result, the power failure starts and power is supplied from the power storage unit 9 to the load 4 and the fuel cell 10 is activated at the same time. When the activation is completed, power can be continuously supplied from the fuel cell 10 to the load 4 for a long time.

When the power failure recovers, the hydrogen tank 11 is replenished with hydrogen of fuel used by the fuel cell 10 during the power failure. The replenishment amount is appropriately controlled while the controller 7 monitors the output of the pressure sensor 12 attached to the hydrogen tank 11. Since the hydrogen generated by the hydrogen generator 13 is used for hydrogen replenishment, it is not necessary to replace the hydrogen tank 11, and a power supply device that can be easily maintained can be realized.
JP 2004-112871 A

  The power supply apparatus as described above can certainly drive the load 4 for a long time even when the main power supply 1 is abnormal, and the maintenance is easy and easy to handle. Reliability is important. Considering the configuration of the power supply device of FIG. 10 from this viewpoint, since the failure of the rectifier 3 is also detected in addition to the detection of the power failure, the power from the fuel cell 10 is supplied even when the rectifier 3 fails. It can be seen that it is configured to improve reliability.

  However, it is not configured to detect any failure or abnormality of the fuel cell 10 itself. Therefore, there is a problem that when the sudden failure of the main power supply 1 occurs at a low frequency such as a power failure, the fuel cell 10 may not be able to generate power if the fuel cell 10 is in an abnormal state. there were.

  An object of the present invention is to solve the above-mentioned conventional problems, and to provide a highly reliable power supply device capable of detecting an abnormality of the fuel cell 10.

  In order to solve the above-described conventional problems, the power supply apparatus of the present invention supplies the hydrogen to the fuel cell when the main power supply is normal and the predetermined condition is satisfied, and causes the fuel cell to generate power under the predetermined condition, thereby The abnormal judgment is performed.

  According to this configuration, the abnormality is determined by monitoring whether the fuel cell can be actually operated to generate power normally. As a result, the object can be achieved.

  According to the power supply device of the present invention, the abnormality of the fuel cell is judged while the main power supply is normal, so that it is possible to reliably generate power with the fuel cell even when the main power supply is abnormal, and an extremely reliable power supply device is provided. It can be realized.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block configuration diagram of a power supply device according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view of the hydrogen generator of the power supply device according to Embodiment 1 of the present invention. FIG. 3 is a flowchart showing the operation of the power supply apparatus according to Embodiment 1 of the present invention.

  In the first embodiment, an example of a power supply device as a stationary uninterruptible power supply system will be described. In FIG. 1, as shown in FIG. 10, a portion indicated by a thick line indicates a power system wiring, a portion indicated by a thin line indicates a control system wiring, and a portion indicated by a dotted arrow indicates a pipe.

  In the configuration of the power supply device according to the first embodiment, the same components as those in the conventional configuration (FIG. 10) are denoted by the same reference numerals.

  In FIG. 1, a main power source 1 is a load 4 such as an emergency light or a computer device that needs to rectify an AC power source 2 which is commercial power into a direct current by a rectifier 3 and continuously supply power during a power failure or the like. Is supplying power. Note that the load 4 is not limited to the one driven by a DC power source, and the load 4 driven by the AC power source may be supplied by returning the output of the rectifier 3 to an AC by an inverter (not shown). Further, the rectifier 3 may incorporate a DCDC converter so as to generate a necessary voltage of the load 4.

  In normal times, power is supplied from the main power supply 1 to the load 4 through the above-described wiring system.

  On the other hand, when the main power source 1 becomes a predetermined voltage or less due to a power failure or a failure of the rectifier 3, power is supplied from the auxiliary power source 5 to the load 4. That is, the power failure detection unit 6 built in the auxiliary power source 5 detects the power failure. The power failure detection unit 6 is composed of, for example, a voltmeter, and when a voltage drop due to a power failure is detected, the power failure detection unit 6 notifies the control unit 7 that controls the entire auxiliary power supply 5 of the power failure.

  As for the failure of the rectifier 3, the rectifier failure detector 8 monitors the output voltage of the rectifier 3, and notifies the controller 7 of the failure signal if the voltage drops below a predetermined voltage at which the load 4 cannot continue to be driven. It is configured.

  When a power failure or a failure of the rectifier 3 occurs, the control unit 7 immediately supplies power to the load 4 from the power storage unit 9 that is built in the auxiliary power source 5 and is constituted by, for example, a secondary battery. Since the power storage unit 9 has a built-in charge / discharge circuit (not shown), the control unit 7 is configured to instruct the charge / discharge circuit to discharge. At the same time, the control unit 7 starts up the fuel cell 10. Therefore, the power storage unit 9 plays a role of supplying power to the load 4 and driving auxiliary equipment such as a blower described later for starting the fuel cell 10 until the fuel cell 10 is started.

  The fuel cell 10 is a hydrogen direct supply type that uses hydrogen as a fuel, and its structure is equivalent to that for a fuel cell vehicle, for example. That is, although not shown, an electrode carrying a noble metal catalyst so that the respective flow paths are opposed to each other between plate separators that form air flow paths through which air flows and hydrogen flow paths through which hydrogen flows. Has a structure in which a single cell having a structure in which a proton conductive polymer membrane formed on both sides is sandwiched with a sealing material for preventing gas leakage is laminated in a number corresponding to the voltage and current characteristics required by the load 4. .

  In order to start up such a fuel cell 10, the control unit 7 supplies hydrogen from the hydrogen tank 11 and air from the blower 14 using a part of the electric power of the power storage unit 9.

  Whether or not the fuel cell 10 has been activated is detected by the voltage detector 15. That is, the fuel cell switch 16 connected to the power output of the fuel cell 10 is off until the fuel cell 10 is completely started up, so that the load 4 is not connected. The electromotive voltage of the fuel cell 10 at this time is detected by the voltage detection unit 15, and if the predetermined voltage is reached, the control unit 7 turns on the fuel cell switch 16 assuming that the start-up is completed. As a result, the electric power of the fuel cell 10 is supplied to the load 4.

  When the power failure is recovered or the rectifier 3 is repaired, power is again supplied from the main power source 1 to the load 4. At this time, the power storage unit 9 is charged from the main power source 1 and the control unit 7 detects the internal pressure attached to the hydrogen tank 11 in order to fill the hydrogen tank 11 with the hydrogen consumed by the fuel cell 10. While monitoring the output of the sensor 12, the hydrogen generated in the hydrogen generator 13 is filled to an appropriate amount. The hydrogen charging is performed when the main power supply 1 is normal because the operating power of the hydrogen generator 13 is supplied based on the power of the main power supply 1.

  A cross-sectional structure of the hydrogen generator 13 is shown in FIG. The main body of the hydrogen generator 13 is composed of a stainless steel sealed box 17. An oxygen pipe 18 for discharging oxygen generated in the hydrogen generator 13 and a hydrogen pipe 19 for discharging hydrogen are connected to the sealed box 17. Since both are made of stainless steel tubes, they are connected to the sealed box 17 by welding. The hydrogen pipe 19 is connected to the hydrogen tank 11 as shown by the dotted arrow in FIG. 1, but the oxygen pipe 18 does not require oxygen, so it may be opened in the air or connected to the blower 14. Then, it may be supplied to the fuel cell 10 together with air.

  Pure water 20 is stored inside the hydrogen generator 13. The pure water 20 generates hydrogen and oxygen by electrolysis, and the storage amount thereof decreases. Therefore, a water amount upper limit sensor 21 is provided in the hydrogen generation unit 13 so that the amount of pure water 20 is always full. Thus, the pure water 20 is always supplied so that the water level reaches the position of the water amount upper limit sensor 21. The pure water 20 may be supplied from a pure water production apparatus that produces pure water from ordinary tap water using an ion exchange resin or the like, or supplied from a pure water tank (not shown) provided with commercially available distilled water. You may do it.

  Here, since the oxygen pipe 18 and the hydrogen pipe 19 have a length up to a position where they do not contact the water surface of the pure water 20, the generated oxygen and hydrogen are always discharged via the space 22. Therefore, the pure water 20 does not enter the oxygen pipe 18 and the hydrogen pipe 19 and can be prevented from being clogged.

  Inside the hydrogen generator 13, an integrally formed water electrolysis element 24 sandwiched between two resin partition plates 23 is disposed. Therefore, the inside of the hydrogen generator 13 is partitioned by the partition plate 23, and the pure water 20 is stored on both sides thereof. In order to supply and store pure water 20 on both sides of the partition plate 23, although not shown in FIG. 2, the bottom of the sealed box 17 on the oxygen tube 18 side and the bottom of the sealed box 17 on the hydrogen tube 19 side are connected by a pipe. It is. Accordingly, when the pure water 20 is supplied to the closed box 17 on the oxygen pipe 18 side, the pure water 20 is also supplied to the hydrogen pipe 19 side through the pipe.

  The detailed configuration of the water electrolysis element 24 will be described later. Further, in FIG. 2, the thickness of the partition plate 23 and the water electrolysis element 24 is shown larger than the actual thickness for the sake of easy understanding.

  Since the lattice-shaped opening 25 is provided in the vicinity of the bottom of the hydrogen generation unit 13 in the partition plate 23, the water electrolysis element 24 is securely held by the partition plate 23, and pure water only in the opening 25. 20 is in contact. Furthermore, since the opening 25 is disposed in the vicinity of the bottom, the electrolysis can be continued even when the storage amount of the pure water 20 decreases.

  The amount of pure water 20 on the hydrogen pipe 19 side is smaller than the amount of pure water 20 on the oxygen pipe 18 side. This is because the pure water 20 on the oxygen tube 18 side is mainly electrolyzed during electrolysis. The reason why pure water 20 is stored also on the hydrogen pipe 19 side and the water electrolysis element 24 is submerged in the pure water 20 is to prevent the water electrolysis element 24 from drying.

  With the above structure, the partition plate 23 separates the oxygen pipe 18 side and the hydrogen pipe 19 side, so that the generated hydrogen and oxygen are not mixed.

  The structure of the water electrolysis element 24 is almost the same as that of a single-cell fuel cell. That is, although not shown in the figure, an electrode made of carbon paper carrying a noble metal catalyst (platinum fine particles are used in the first embodiment) on both sides of the proton conductive polymer membrane is thermocompression-bonded, and there is an electrode. A portion where the gas sealing resin is disposed is provided in the portion not to be used. A mesh-like metal electrode for supplying electric power from the outside is disposed on the electrode, and is integrally formed with the partition plate 23. The mesh-like metal electrode is electrically insulated from the sealed box 17 and connected to the external wiring in an airtight state. The external wiring is wired so that the hydrogen pipe 19 side is a negative electrode (ground) and the oxygen pipe 18 side is a positive electrode.

  The schematic operation of the electrolysis of pure water 20 by the hydrogen generator 13 is as follows.

  When electric power is supplied between the mesh metal electrodes through the external wiring, the pure water 20 is decomposed into oxygen, protons and electrons on the positive electrode catalyst. Among these, oxygen is gasified as it is and is discharged from the oxygen pipe 18 via the space 22.

  On the other hand, protons pass through the proton conducting polymer membrane and electrons pass through the external circuit to reach the negative electrode. In the negative electrode, both react on the catalyst to generate hydrogen. Hydrogen is discharged from the hydrogen pipe 19 via the space 22.

  The pure water 20 is electrolyzed as described above.

  A temperature sensor 26 is provided in the vicinity of the bottom of the hydrogen generator 13. Thereby, freezing of the pure water 20 is monitored. That is, if the output of the temperature sensor 26 is equal to or lower than a predetermined temperature (5 ° C. in the first embodiment), the pure water 20 cannot be electrolyzed because there is a possibility of freezing. Accordingly, the hydrogen tank 11 is controlled not to be replenished with hydrogen, and a heat generating circuit component (such as an FET) (not shown) is in contact with the outer surface of the hydrogen generator 13 so that the temperature of the hydrogen generator 13 can be raised as quickly as possible. Are arranged to be. As a result, not only the temperature of the hydrogen generating unit 13 is raised but also the heat of the heat generating circuit component is absorbed by the hydrogen generating unit 13 having a large heat capacity, so that heat generation is suppressed and stable circuit driving is possible, contributing to high reliability.

  Here, the predetermined temperature is set to 5 ° C. because the density of the pure water 20 is the highest when the density is 4 ° C. That is, when the pure water 20 frozen in the hydrogen generator 13 melts and becomes liquid, the density increases and reaches the bottom of the hydrogen generator 13. Therefore, the bottom of the hydrogen generation unit 13 is always around 4 ° C. while the pure water 20 is deicing. Eventually, when all the pure water 20 is melted, the water temperature at the bottom of the hydrogen generator 13 rises. From these points, it can be seen that if the output of the temperature sensor 26 disposed near the bottom of the hydrogen generator 13 is higher than, for example, 5 ° C., the pure water 20 is entirely liquid. Therefore, the predetermined temperature was set to 5 ° C.

  With the above configuration, a highly reliable hydrogen generation unit 13 can be configured.

  A constant current source 27 is connected to the hydrogen generator 13 in order to electrolyze the pure water 20. The operation of the constant current source 27 is controlled by a hydrogen generator switch 28. The constant current source 27 is supplied with power from the AC power source 2, and this is internally converted to a DC power source to supply a DC constant current to the hydrogen generator 13.

  Next, the most characteristic part of the first embodiment will be described.

  In the power supply device according to the first embodiment, when the main power supply 1 is normal and at a predetermined condition (for example, every predetermined time interval such as once a day), the control unit 7 supplies hydrogen from the hydrogen tank 11 to the fuel cell 10. By supplying air from the blower 14, the fuel cell 10 is actually generated under predetermined conditions. At this time, whether or not the fuel cell 10 is abnormal is determined by detecting the output voltage by the voltage detection unit 15 as to whether or not normal power generation is possible. If abnormal, the control unit 7 issues a warning.

  In a specific configuration, a constant current load 29 is connected to the output of the fuel cell 10 so that the electric power generated by the fuel cell 10 is consumed with a predetermined constant current. In addition, since the constant current load switch 30 is provided between them, the constant current load switch 30 is controlled to be turned on when the above-described abnormality determination default condition of the fuel cell 10 is satisfied. With such a configuration, the fuel cell 10 can operate normally even if a sudden power outage or the like occurs, so that an extremely reliable power supply device can be realized.

  Next, an operation example of the power supply device according to the first embodiment will be specifically described with reference to the flowchart of FIG. 3 is executed by the control unit 7.

  First, the failure determination of the rectifier 3 is performed based on the output of the rectifier failure detector 8 (step number S1). If there is a failure (Yes in S1), the controller 7 issues a rectifier abnormality warning (S2) to notify the user. The user performs processing such as repair of the rectifier 3 in accordance with this warning. After issuing the warning, the process jumps to S18 described later.

  On the other hand, if the rectifier 3 is normal (No in S1), the presence / absence of a power failure is determined based on the output of the power failure detection unit 6 (S3). If a power failure has occurred (Yes in S3), the routine jumps to a routine (after S18) for switching to power supply by the power storage unit 9 and the fuel cell 10 described later.

  If there is no power failure (No in S3), the main power supply 1 is normal. Next, the output of the temperature sensor 26 of the hydrogen generator 13 is read, and below a predetermined temperature (here, 5 ° C.). That is, the possibility of freezing the pure water 20 is determined (S4). If it is equal to or lower than the predetermined temperature (Yes in S4), there is a possibility of freezing. Therefore, it is impossible to replenish the hydrogen used for the abnormality determination of the fuel cell 10 after the determination. Therefore, there is a possibility that the time during which the fuel cell 10 can generate power in the event of an abnormality in the main power supply 1 may be shortened. In this case, the abnormality determination of the fuel cell 10 is not performed and the process returns to S1. By repeating the operation of returning to S1 in this way, it waits for the temperature of the pure water 20 to rise, and the abnormality determination is made only when the temperature becomes higher than the predetermined temperature.

  On the other hand, if the temperature is higher than the predetermined temperature (No in S4), the abnormality determination of the fuel cell 10 is performed next. That is, it is first determined whether a predetermined time (in this case, every day) for determining abnormality of the fuel cell 10 has elapsed (S5). If it has not elapsed (No in S5), the process returns to S1 again, and the operations after the failure determination of the rectifier 3 are repeated.

  When the predetermined time has elapsed (Yes in S5), the valve (not shown) of the hydrogen tank 11 is opened to supply hydrogen to the fuel cell 10 and the blower 14 is turned on to supply air. The constant current load switch 30 Is turned on (S6). Thereby, the fuel cell 10 starts power generation, and the power generated by the constant current load 29 is consumed.

  Next, the voltage detector 15 detects the output voltage of the fuel cell 10 when the constant current load 29 is consuming the generated power. The constant current load 29 is set to consume power determined in advance such as average power and maximum power consumed by the load 4. Therefore, by detecting the output voltage of the fuel cell 10 under the same conditions as when the fuel cell 10 is actually generating power when the main power source 1 is abnormal, it is possible to make a more accurate abnormality determination and further increase the reliability. can get.

  If the voltage of the fuel cell 10 is abnormal (No in S7), the fuel cell 10 is abnormal. In this case, first, the constant current load switch 30 is turned off to stop the power consumption of the fuel cell 10, and a fuel cell abnormality warning is issued (S8). As a result, the user can take measures such as repairing the fuel cell 10.

  Further, the hydrogen supply to the fuel cell 10 is stopped (here, the valve of the hydrogen tank 11 is closed), and the blower 14 is turned off to stop the air supply (S9). Further, since the auxiliary power supply 5 cannot function normally as it is, the flowchart is ended, but the warning continues to be issued to prompt repair.

  On the other hand, returning to S7, if the voltage of the fuel cell 10 is normal (Yes in S7), it has been found that the fuel cell 10 is operating normally. The constant current load switch 30 is turned off, the hydrogen supply to the fuel cell 10 is stopped, the blower 14 is turned off, and the air supply is also stopped (S10). Thereby, the power generation operation of the fuel cell 10 is stopped.

  Next, since the hydrogen in the hydrogen tank 11 is consumed in connection with the abnormality determination of the fuel cell 10, the pressure in the hydrogen tank 11 is equal to or lower than a predetermined pressure (for example, about 10 MPa which is a full filling pressure of a general hydrogen cylinder). If so (Yes in S11), hydrogen is charged until a predetermined pressure is reached.

  That is, first, if the output of the temperature sensor 26 of the hydrogen generation unit 13 is equal to or lower than the predetermined temperature (5 ° C.) (Yes in S12), the pure water 20 may be frozen, so hydrogen cannot be replenished. In this case, the process returns to S1 without replenishment.

  On the other hand, if the temperature is higher than the predetermined temperature (No in S12), the hydrogen generator switch 28 is turned on (S13). As a result, the AC power supply 2 is supplied to the constant current source 27, converted into a DC constant current, and supplied to the hydrogen generator 13. Thereby, hydrogen is generated.

  Although the generated hydrogen is filled in the hydrogen tank 11, the method is not particularly shown, but a general method in which a pressure higher than the pressure in the hydrogen tank 11 is generated by combining a compressor, a reservoir tank, or the like may be used. Absent.

  Then, it returns to S11 and performs the operation | movement after the judgment whether the pressure of the hydrogen tank 11 reached predetermined pressure.

  If the pressure in the hydrogen tank 11 has reached the predetermined pressure (No in S11), the hydrogen generator switch 28 is turned off (S14), and the hydrogen supply is stopped. Thereafter, it is determined whether or not the water amount upper limit sensor 21 provided in the hydrogen generator 13 is on (S15). The water amount upper limit sensor 21 has a characteristic that it is turned on when the pure water 20 reaches the water amount upper limit sensor 21 and is turned off when it has not reached. Therefore, if the water amount upper limit sensor 21 is off (No in S15), pure water is supplied to the hydrogen generator 13 by opening a pure water valve (not shown) (S16). Then, it returns to S15 and continues water supply until it becomes full.

  If the water amount upper limit sensor 21 is turned on (Yes in S15), the pure water 20 is full in the hydrogen generator 13, so the supply of the pure water 20 is stopped (S17), and the process returns to S1. .

  The above is the operation when the main power supply 1 is normal. Next, the operation when there is an abnormality will be described.

  When a power failure is detected in S3 after issuing an abnormality warning of the rectifier 3 in S2, first, the power of the power storage unit 9 is output to the load 4 and hydrogen is supplied from the hydrogen tank 11 to the fuel cell 10. At the same time, the blower 14 is turned on to supply air (S18). Thereby, the fuel cell 10 is started. Note that the power of the power storage unit 9 is first supplied to the load 4 even though the fuel cell 10 is of a direct hydrogen supply type and the abnormality is determined once a day and the activation is confirmed in advance. This is because it takes several seconds to complete.

  Next, the electromotive voltage of the fuel cell 10 is detected by the voltage detector 15 (S19). In this case, since the fuel cell switch 16 is off, the fuel cell 10 is in a no-load state. Therefore, it is determined whether or not the startup is performed using the electromotive voltage at the completion of startup as the default voltage, instead of the voltage at the time of power generation, which is a determination criterion at the time of abnormality determination.

  If the electromotive voltage of the fuel cell 10 has not reached the predetermined voltage (No in S19), the process returns to S19 again to wait for the predetermined voltage. If the predetermined voltage is reached (Yes in S19), the fuel cell switch 16 is turned on to switch the power from the power storage unit 9 to the fuel cell 10 (S20).

  Thereafter, it is determined whether or not the power failure has been recovered by the output of the power failure detection unit 6 (S21). If the power failure has not yet recovered (No in S21), the pressure in the hydrogen tank 11 is monitored while continuing to supply power from the fuel cell 10 to the load 4. If the pressure does not drop to a predetermined pressure (here, 2 kPa, for example, in which there is almost no residual pressure in the hydrogen tank 11) (No in S22), the hydrogen still remains in the hydrogen tank 11, so the process returns to S21. Continue the operation after the power failure recovery decision. If the predetermined pressure is set to 0, gas other than hydrogen may be mixed in the hydrogen tank 11, so that the predetermined voltage is set to about 2 kPa in order to leave a slight residual pressure.

  On the other hand, if the pressure in the hydrogen tank 11 becomes equal to or lower than the predetermined pressure and there is almost no hydrogen in the hydrogen tank 11 (Yes in S22), the fuel cell 10 cannot generate any more power, so the fuel cell switch 16 is turned off. Then, a hydrogen shortage warning is issued (S23). Thereafter, the process jumps to S9 to stop the supply of hydrogen and air, and the flowchart is ended.

  By performing such an operation, power cannot be supplied to the load 4. However, when the main power supply 1 is abnormal, most of the electric power is always supplied by the fuel cell 10 in a state where the hydrogen tank 11 is fully filled with hydrogen. Therefore, the power storage unit 9 has the same volume as the first embodiment. Compared with a power supply device that supplies power to the load 4 alone, it can be supplied for a long time, and the reliability when the main power supply 1 is abnormal is improved.

  Now, returning to S21, if the power failure of the main power supply 1 is recovered (Yes in S21), the failure of the rectifier 3 is determined (S24). If the power failure is detected (Yes in S24), Since power cannot be supplied from the main power source 1 to the load 4, in order to continue supplying power from the fuel cell 10 to the load 4, the process jumps to S <b> 22 and performs operations after the pressure determination of the hydrogen tank 11. This operation corresponds to the case where the failure of the rectifier 3 and a power failure occur at the same time. In this case, since the rectifier device 3 remains broken even if the power failure is recovered, the operation continues from the fuel cell 10. Continue to supply power.

  On the other hand, if the rectifier 3 is normal (No in S24), power can be supplied from the main power supply 1 and power generation by the fuel cell 10 is not required. Therefore, the supply of hydrogen from the hydrogen tank 11 is immediately stopped. Then, the blower 14 is turned off to stop the air supply, the fuel cell switch 16 is turned off, and the power supply to the load 4 is stopped (S25). Thereafter, in order to replenish the hydrogen tank 11 with hydrogen consumed during the power failure, the operations after S11 are performed.

  The above is the basic operation of the power supply device according to the first embodiment. Actually, more detailed operations (for example, charging operation after discharging the power storage unit 9 and control of various valves not shown) are performed, but are omitted here. Although not shown in the flowchart of FIG. 3, an interrupt routine that always performs abnormality determination of the main power source 1 such as power failure and failure monitoring of the rectifier 3 is executed separately from FIG. 3, for example, after S6 of FIG. If an abnormality of the main power supply 1 is detected during the fuel cell abnormality determination, etc., processing such as abnormality determination of the fuel cell 10 is immediately stopped, and a jump is made to the operation routine of the auxiliary power supply 5 after S18. As a result, no matter what processing the control unit 7 is executing, it is possible to quickly respond to the abnormality of the main power supply 1, thereby realizing a highly reliable power supply apparatus.

  With the above-described configuration and operation, abnormality determination (startup confirmation) is performed by monitoring whether the fuel cell 10 can be actually operated under normal conditions to generate power normally. It is possible to generate power with the fuel cell 10 and to realize a highly reliable power supply device.

  In the first embodiment, the hydrogen generation unit 13 is configured by an electrolysis type of pure water 20, but is not limited to this. For example, city gas, propane gas, kerosene or the like is reformed by a reformer. After that, only hydrogen may be extracted and purified with a palladium membrane or the like.

(Embodiment 2)
FIG. 4 is a block configuration diagram of a power supply device according to Embodiment 2 of the present invention. FIG. 5 is a flowchart showing the operation of the power supply apparatus according to Embodiment 2 of the present invention.

  In the second embodiment, an example of a power supply device as a stationary uninterruptible power supply system will be described. In addition, the meanings of thick lines, thin lines, and dotted arrows in FIG. 4 are the same as those in the first embodiment.

  In FIG. 4, the same components as those in FIG. That is, the structural feature of the second embodiment is that an electric switching valve 31 is provided in the pipe between the hydrogen generator 13 and the hydrogen tank 11 in FIG. The switching valve 31 has a three-way valve structure and supplies hydrogen generated from the hydrogen generator 13 to the hydrogen tank 11 by a built-in motor, supplies the hydrogen tank 11 directly to the fuel cell 10 or bypasses the hydrogen tank 11. Depending on the angle, the hydrogen generation unit 13 can be closed so that hydrogen does not flow in either direction.

  With such a configuration, the hydrogen generated by the hydrogen generator 13 can be supplied to both the hydrogen tank 11 and the fuel cell 10. Accordingly, when the abnormality of the fuel cell 10 is judged, the amount of hydrogen consumed by the power generation is small. Therefore, the abnormality is judged using the hydrogen generated by the hydrogen generator 13, and the main power source 1 becomes abnormal and the fuel cell 10 is operated for a long time When replenishing the hydrogen tank 11 with the hydrogen consumption due to the above, the hydrogen generated in the hydrogen generator 13 is filled in the hydrogen tank 11 as in the first embodiment.

  As a result, in the first embodiment, hydrogen is supplied from the hydrogen tank 11 at the time of abnormality determination of the fuel cell 10, so that hydrogen is replenished to the hydrogen tank 11 at each abnormality determination. Since no hydrogen in the hydrogen tank 11 is used at the time of determination, hydrogen replenishment after the abnormality determination becomes unnecessary. As a result, when the main power supply 1 becomes abnormal during hydrogen replenishment, the hydrogen tank 11 is always fully filled with hydrogen, so that the longest power supply to the load 4 is possible at any time, and the reliability is further improved. .

  Next, the basic operation of this power supply apparatus will be described with reference to the flowchart of FIG. In FIG. 5, the same step numbers are assigned to parts that perform the same operations as those in FIG. 3, and detailed descriptions thereof are omitted.

  5 differs from FIG. 3 in a routine (S26 and subsequent steps) for determining abnormality of the fuel cell 10 when the main power source 1 is normal. That is, when the conditions for determining the abnormality of the fuel cell 10 are met in S1, S3, S4, and S5, the control unit 7 first switches the switching valve 31 to the fuel cell 10 side. Next, the hydrogen generator switch 28 is turned on. As a result, a constant DC current is supplied from the constant current source 27 to the hydrogen generator 13 to generate hydrogen. This hydrogen is directly supplied to the fuel cell 10 through the bypass by the switching valve 31. At the same time, the blower 14 is turned on to supply air. Thus, since the fuel cell 10 is ready for power generation, the constant current load switch 30 is turned on to cause the fuel cell 10 to generate power (S26). The power generation conditions (load consumption conditions) at this time are the same as those in the first embodiment.

  Next, it is determined whether or not the voltage across the fuel cell 10 is normal (S7). If the voltage is abnormal (No in S7), the switching valve 31 is immediately switched to the hydrogen tank 11 side to connect to the fuel cell 10. The hydrogen supply is stopped, and at the same time, the hydrogen generation unit switch 28 is turned off to stop the hydrogen generation. Further, the constant current load switch 30 is turned off to stop the power generation by the fuel cell 10, and a fuel cell abnormality warning is issued (S27). Thereafter, the blower 14 is turned off to stop the air supply (S28), and the flowchart is ended.

  On the other hand, if the fuel cell 10 is normal in S7 (Yes in S7), there is no need to continue power generation, so the switching valve 31 is immediately switched to the hydrogen tank 11 side to stop the supply of hydrogen to the fuel cell 10. At the same time, the hydrogen generation unit switch 28 is turned off to stop hydrogen generation. Further, the blower 14 is turned off to stop air supply, and the constant current load switch 30 is turned off (S29). Thereby, the power generation by the fuel cell 10 is stopped.

  After that, as in the first embodiment, the operation after the pressure determination of the hydrogen tank 11 (S11 and subsequent steps) is performed. In the second embodiment, no hydrogen is used in the hydrogen tank 11 when the abnormality of the fuel cell 10 is determined. However, the pressure of the hydrogen tank 11 is still determined from the hydrogen tank 11 for a long time. This is because there is a possibility that hydrogen will gradually decrease within the range, and the pressure drop due to this may be monitored. Therefore, if the predetermined pressure is not reached, even if the hydrogen of the hydrogen tank 11 is not used in the abnormality determination of the fuel cell 10, hydrogen is charged until the predetermined pressure is reached. Thereby, the hydrogen tank 11 is always filled with hydrogen, and a highly reliable power supply device can be realized.

  Next, the difference from the first embodiment is when the hydrogen in the hydrogen tank 11 runs out when the main power source 1 is abnormal and power is being supplied from the fuel cell 10 to the load 4 (Yes in S22). Here, since S27 is an operation different from S8 in FIG. 3, only a difference appears in the notation of the flowchart, and the operation (S30 → S28) itself is exactly the same as in the first embodiment.

  The operation flowchart other than the above is the same as FIG.

  With the above configuration and operation, when the abnormality of the fuel cell 10 is determined, the hydrogen generation unit 13 generates hydrogen and determines the abnormality of power generation. Therefore, it is possible to determine the abnormality without reducing the hydrogen in the hydrogen tank 11. A power supply for a long time can be supplied to the load 4 at any time in the event of an abnormality, and a highly reliable power supply device can be realized.

(Embodiment 3)
FIG. 6 is a block configuration diagram of a power supply device according to Embodiment 3 of the present invention. FIG. 7 is a cross-sectional view of the hydrogen generation part of the power supply device according to Embodiment 3 of the present invention. FIG. 8 is a flowchart showing the operation of the power supply apparatus according to Embodiment 3 of the present invention. FIG. 9 is a correlation diagram of the current supplied to the hydrogen generator with respect to the temperature of the hydrogen generator as the drive condition for determining the fuel cell abnormality of the power supply device according to Embodiment 3 of the present invention.

  In the third embodiment, an emergency power supply apparatus during vehicle braking will be described as an example of in-vehicle use. The meanings of the thick line, thin line, and dotted line arrow in FIG. 6 are the same as those in the first embodiment.

  6 and 7, the same components as those in FIGS. 4 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted. That is, the third embodiment basically has the same structure as that of the second embodiment, but the following structural features will be described with reference to FIGS.

  1) Since the main power source 1 corresponds to a battery and is originally a direct current, there is no rectifier 3.

  2) Accordingly, the rectifier failure detection unit 8 is not provided, and a main power supply voltage detection unit 32 having substantially the same configuration is provided instead of the power failure detection unit 6.

  3) Since there is no supply source of pure water (such as tap water), the pure water supply to the hydrogen generator 13 is not automatically performed, and the hydrogen generator is manually operated when a water shortage warning occurs or when the vehicle is regularly checked. 13 was supplied with pure water 20.

  4) Along with this, the water amount upper limit sensor 21 was abolished.

  5) In order to detect the remaining amount of the pure water 20, the current flowing through the water electrolysis element 24 when hydrogen is generated is obtained. Therefore, a current sensor (not shown) is built in the constant current source 27.

  6) The pure water 20 stored in the hydrogen generator 13 was impregnated in a sponge-like resin 33 as shown in FIG. 7 in order to avoid fluctuations in the liquid level due to vehicle vibration.

7) A hydrogen storage alloy (for example, LaNi ₅ ) made of an alloy containing a rare earth was built in the hydrogen tank 11. As a result, the pressure at the time of full filling of hydrogen can be lowered to about 2 MPa, which eliminates the need for a high pressure resistant design, enables downsizing of the hydrogen tank 11, and eliminates the need for a compressor, a reservoir tank, etc. Therefore, reliability is improved.

  8) In order to release hydrogen as quickly as possible when the main power supply 1 is abnormal, a hydrogen tank 11 is disposed in the vicinity of the fuel cell 10 as shown in FIG. 6, and the heat of the fuel cell 10 during power generation is transferred to the hydrogen tank 11. I communicated.

  9) The abnormality determination of the fuel cell 10 is performed every time the vehicle is started.

  10) The size of the mounted fuel cell 10 is such that it can supply enough power to drive the vehicle braking load 4 and stop the vehicle safely when the main power source 1 is abnormal.

  11) Accordingly, since the amount of hydrogen stored in the hydrogen tank 11 needs to be able to generate the above-mentioned electric power at a minimum, the size enough to store the amount of hydrogen with a safety factor of 5 times, and the amount of hydrogen storage alloy It was.

  12) The hydrogen tank 11 was not charged with hydrogen during use of the vehicle. Therefore, as shown in FIG. 6, the piping from the hydrogen generator 13 to the hydrogen tank 11 is eliminated, and the switching valve 31 is changed to a hydrogen valve 31a that only supplies and stops hydrogen. Since the hydrogen valve 31a is always closed except when the abnormality of the fuel cell 10 is judged, the backflow of hydrogen from the hydrogen tank 11 to the hydrogen generator 13 is prevented when the main power supply 1 is abnormal.

  The above are the main structural changes. Among these, the current sensor and the structure of the hydrogen generator 13 will be described in detail below.

  First, the current sensor related will be described.

  The presence or absence of pure water 20 in the hydrogen generator 13 is monitored by a current sensor (not shown) built in a constant current source 27 that supplies power to the hydrogen generator 13 in order to electrolyze the pure water 20. That is, if the pure water 20 is lost, protons cannot be conducted through the water electrolysis element 24, so that hydrogen cannot be generated, and therefore no current flows.

  Therefore, if the output of the current sensor does not reach the predetermined current, it is determined that there is no pure water 20. In this case, a water shortage warning is given to the driver and water supply of pure water 20 is urged.

  Next, the structural relationship of the hydrogen generator 13 will be described with reference to FIG.

  The greatest difference from the hydrogen generation unit 13 described in the first embodiment is that pure water 20 is impregnated in a sponge-like resin 33. Specifically, two sponge-like resins 33, that is, a sponge-like resin disposed on the hydrogen tube 19 side (hereinafter referred to as hydrogen tube-side sponge-like resin 33a) and an oxygen tube 18 side are provided inside the hydrogen generation unit 13. An arranged sponge-like resin (hereinafter referred to as oxygen tube side sponge-like resin 33b) is arranged. Both of the sponge-like resins 33 have a porosity of 80%, and are stored in a state in which the pores are impregnated with pure water 20. By storing the pure water 20 in this way, it is possible to prevent the oxygen pipe 18 and the hydrogen pipe 19 from being clogged due to scattering of water due to vibration of the vehicle.

  As described in the first embodiment, since pure water 20 on the oxygen tube 18 side is mainly consumed during electrolysis, the hydrogen tube side sponge-like resin 33a is used as the oxygen tube side sponge as shown in FIG. It is smaller than the resin 33b. Further, the pure water 20 is also impregnated into the hydrogen pipe side sponge-like resin 33a in order to prevent the water electrolysis element 24 from drying.

  Here, the oxygen pipe 18 and the hydrogen pipe 19 have a length up to a position where they do not come into contact with the oxygen pipe side sponge-like resin 33b and the hydrogen pipe side sponge-like resin 33a, respectively. As a result, the generated oxygen and hydrogen are always discharged through the space 22, and therefore, clogging of the pure water 20 contained in the sponge-like resin 33 inside the oxygen pipe 18 and the hydrogen pipe 19 can be prevented.

  The opening 25 is provided in the vicinity of the bottom of the hydrogen generator 13, and only the water electrolysis element 24 located in the opening 25 is in contact with the sponge-like resin 33, so that the remaining amount of pure water 20 is reduced. Even in the vicinity of the bottom, the pure water 20 is contained in the sponge-like resin 33 and the electrolysis can be continued.

  Further, from the result of obtaining the amount of pure water that can be used to determine the amount of hydrogen used for one abnormality determination of the fuel cell 10 under the condition that the vehicle life is 15 years and the vehicle is started twice a day, The size was set to about 1 L (liter) with a margin. Other parts not specifically described have the same structure as that of the first embodiment.

  Based on the above structural features, the operation of the power supply apparatus according to the third embodiment will be described with reference to the flowchart of FIG.

  First, when the vehicle is started, power is supplied to the control unit 7 and the flowchart of FIG. 8 is executed. Thereby, the abnormality determination flag is first turned off (S51). The abnormality determination flag is a flag indicating whether or not the abnormality determination of the fuel cell 10 has been performed after the vehicle is started. If the flag is turned on, the abnormality determination is performed. The reason for using this abnormality determination flag is to indicate that the abnormality determination of the fuel cell 10 could not be performed at the time of starting the vehicle at a low temperature or the like.

  Next, it is determined whether or not the output of the temperature sensor 26 is equal to or lower than a predetermined temperature (5 ° C.) (S52). This is for detecting the possibility of freezing of the hydrogen generator 13, and at the time of low temperature, abnormality determination of the fuel cell 10 is not performed until the temperature becomes higher than the predetermined temperature.

  If the temperature is equal to or lower than the predetermined temperature (Yes in S52), the abnormality determination is not performed and the operation after the abnormality monitoring of the main power source 1 (S61 and after) is performed. This will be described later.

  On the other hand, if the temperature is higher than the predetermined temperature (No in S52), an abnormality determination routine for the fuel cell 10 is executed. That is, first, since the condition for performing the abnormality determination is set, the abnormality determination flag is turned on. Next, the output constant current value of the constant current source 27 according to the current temperature is set. Further, the hydrogen valve 31a is opened to turn on the hydrogen generator switch 28 (S53). As a result, the constant current set from the constant current source 27 is supplied to the water electrolysis element 24 of the hydrogen generator 13 to generate hydrogen and oxygen.

  Here, the reason why the constant current value is changed according to the temperature will be described.

  Since the generated hydrogen is a gas, the amount of hydrogen generated within a predetermined time greatly varies depending on the environmental temperature when electrolyzed with a constant current. Since the amount of hydrogen to be generated is determined by the size of the fuel cell 10, if the electrolysis is simply performed at a constant current, the time for obtaining the required amount of hydrogen varies greatly depending on the temperature, and it takes time especially at low temperatures. . Therefore, in order to generate the same amount of hydrogen within a certain time, it is necessary to change the current value according to the temperature.

  Here, the electrolysis time was set to 1 minute. This is because, as a result of obtaining the amount of hydrogen that can be generated from the current value and the magnitude that can be passed through the water electrolysis element 24, it has been found that unless the water electrolysis element 24 is set to about 1 minute, the water electrolysis element 24 must be increased in size and current. It is. Although there is a possibility that the main power supply 1 becomes abnormal during electrolysis (for 1 minute) or the like, the interrupt routine monitors the abnormality of the main power supply 1 as described in the operation of the first embodiment. Like to do. Accordingly, when the main power source 1 becomes abnormal, it is possible to immediately stop processing such as abnormality determination of the fuel cell 10 and supply power to the load 4, thereby obtaining high reliability.

  FIG. 9 is a graph showing the results of obtaining the electrolysis current depending on the environmental temperature under the above electrolysis conditions. In FIG. 9, the horizontal axis indicates the environmental temperature, that is, the temperature of the hydrogen generator 13 (obtained by the temperature sensor 26), and the vertical axis indicates the electrolytic current that flows through the water electrolysis element 24. As can be seen from FIG. 9, the lower the temperature, the less hydrogen is generated. However, since the maximum current is about 10 A within the operating temperature range (5 ° C. to 85 ° C.), it is not necessary to provide a wiring system corresponding to a large current.

  In addition, since the voltage applied to the water electrolysis element 24 in the current range of FIG. 9 was at least about 3V, it exceeded the voltage required for water electrolysis (about 2V), and water can be electrolyzed at any temperature. I found out that

  As described above, since the control unit 7 stores data based on the graph of FIG. 9, the control unit 7 obtains a predetermined current for electrolysis corresponding to the current temperature and transmits it to the constant current source 27.

  Here, returning to the flowchart of FIG. 8, it is detected by the current sensor built in the constant current source 27 whether the set constant current is flowing. If the predetermined current is not flowing, the pure water 20 of the hydrogen generation unit 13 is insufficient, and the process jumps to a routine for warning of water shortage (S60 and later).

  On the other hand, if the predetermined current is flowing (Yes in S54), hydrogen is normally generated and supplied to the fuel cell 10, so that the blower 14 is turned on to supply air and the constant current load switch 30 is turned on. Turn on and start power generation of the fuel cell 10 (S55). At this time, the load current condition of the constant current load 29 (power generation condition of the fuel cell 10) is set so as to be the average or maximum power condition that the load 4 actually consumes as described in the first embodiment. It is.

  Next, the voltage detector 15 detects the voltage across the fuel cell 10. If this does not reach the predetermined voltage and is an abnormal value (No in S56), it can be determined that the fuel cell 10 is abnormal. In this case, the hydrogen valve 31a is immediately closed, both the hydrogen generation unit switch 28 and the constant current load switch 30 are turned off, and an abnormality warning of the fuel cell 10 is given to the driver (S57). Thereafter, by turning off the blower 14 (S58), the fuel cell 10 is stopped and the flowchart is ended. Since the warning at this time is continuously issued, it is possible to prompt the driver to repair the fuel cell 10.

  In this case, since the electric power cannot be supplied from the fuel cell 10 even if the main power supply 1 becomes abnormal, the vehicle-side control device (not shown) switches from electrical hydraulic control to mechanical hydraulic control. Thereby, even if the main power supply 1 becomes abnormal during traveling, the vehicle can be stopped by the hydraulic pressure generated by the pedaling force although the brake pedal becomes heavy.

  Now, returning to S56 of the flowchart, if it is found that the fuel cell 10 is normal (Yes in S56), there is no need to waste the pure water 20 any more, so the hydrogen generator switch 28 is immediately turned off. Then, the generation of hydrogen is stopped, the blower 14 is turned off, the air supply is stopped, the constant current load switch 30 is turned off, and the hydrogen valve 31a is closed to stop the power generation of the fuel cell 10 (S59). Thereafter, the routine jumps to a routine (S61) after the abnormality determination of the main power source 1.

  Returning to S54, if the predetermined current is not reached (No in S54), the pure water 20 is insufficient, so the hydrogen valve 31a is immediately closed and the hydrogen generator switch 28 is turned off. Then, the operation of the hydrogen generator 13 is stopped, and the driver is warned of the lack of pure water (S60). This prompts the driver to supply the pure water 20 to the hydrogen generator 13. After this, although the pure water 20 is insufficient, the fuel cell 10 is normal and the hydrogen in the hydrogen tank 11 is not used. Therefore, even if the main power supply 1 becomes abnormal, power can be supplied to the load 4. Therefore, the normal abnormality monitoring routine for the main power supply 1 is entered next (S61 and after).

  First, the voltage of the main power supply 1 is detected by the main power supply voltage detection unit 32, and it is determined whether it is abnormal (S61). Here, since the main power source 1 is a battery in the third embodiment, the minimum output voltage of the battery, 9.5 V, is set as the default voltage, and it is determined that there is an abnormality when the voltage is lower than that due to disconnection or the like.

  If there is no abnormality (No in S61), it is determined whether the output of the temperature sensor 26 is equal to or lower than a predetermined temperature (5 ° C.) (S62). This means that when the abnormality of the fuel cell 10 cannot be determined at a low temperature, it is determined whether or not the temperature at which the abnormality can be determined has been reached at the present time. If the temperature is still below the predetermined temperature (Yes in S62), the process returns to S61 again and the operation after the monitoring of the main power supply 1 is repeated.

  On the other hand, if the temperature is higher than the predetermined temperature (No in S62), then the state of the abnormality determination flag is examined (S63). If the abnormality determination flag is on (No in S63), the abnormality determination of the fuel cell 10 has already been completed, so the process returns to S61 again and the operation after the monitoring of the main power supply 1 is repeated.

  On the other hand, if the abnormality determination flag is off (Yes in S63), the abnormality determination of the fuel cell 10 has not yet been performed, but it is known in S62 that the temperature is higher than the predetermined temperature. It can be carried out. Accordingly, the process jumps to S53, and the abnormality determination routine is executed.

  Here, returning to S61, if the voltage of the main power supply 1 is abnormal (Yes in S61), the power of the power storage unit 9 is immediately output to the load 4 and the start of the fuel cell 10 is started at the same time. Specifically, the hydrogen valve 31a is closed so that high-pressure hydrogen in the hydrogen tank 11 does not flow back to the hydrogen generator 13, and hydrogen is supplied from the hydrogen tank 11 to the fuel cell 10, and air is also supplied by turning on the blower 14. (S64). In this state, the voltage detector 15 detects the electromotive voltage of the fuel cell 10. If the electromotive voltage has not reached the predetermined voltage for driving the load 4 (No in S65), the process returns to S65 again and waits until the predetermined voltage is reached.

  When the predetermined voltage is reached (Yes in S65), the fuel cell 10 is ready for power generation, so the fuel cell switch 16 is turned on to supply power to the load 4 (S66). Next, the main power supply voltage detector 32 monitors the voltage of the main power supply 1. If the voltage of the main power supply 1 recovers for some reason (Yes in S67), the hydrogen supply to the fuel cell 10 is immediately stopped, the blower 14 is turned off, and the fuel cell switch 16 is turned off. In order to replenish the hydrogen used from the hydrogen tank 11 to the full amount, a hydrogen filling warning is issued to the driver (S68). As a result, the fuel cell 10 is stopped, and wasteful consumption of hydrogen can be suppressed. Furthermore, when the driver fills the hydrogen tank 11 with hydrogen in accordance with the hydrogen filling warning, the fuel cell 10 can be sufficiently activated even when the abnormality of the main power source 1 occurs again, and reliability is improved.

  On the other hand, if the main power source 1 has not recovered in S67, the output of the pressure sensor 12 is read, and the pressure of the hydrogen tank 11 is a predetermined pressure (2kPa, which is a lower limit pressure for preventing gas such as air from flowing into the hydrogen tank 11). It is determined whether or not the following is true (S69). If it is higher than the predetermined pressure (No in S69), there is still hydrogen, so the process returns to S67 while continuing the power generation of the fuel cell 10, and the operation after the main power supply recovery determination is performed.

  On the other hand, if the pressure is equal to or lower than the predetermined pressure (Yes in S69), the hydrogen has disappeared, so the fuel cell switch 16 is immediately turned off, the driver is warned of hydrogen shortage, and the hydrogen supply to the fuel cell 10 is stopped. (S70). Further, jumping to S58 and turning off the blower 14, the power generation of the fuel cell 10 is stopped, and the flowchart is ended. Also in this case, since the fuel cell 10 can no longer generate power while the main power supply 1 remains abnormal, the vehicle control device (not shown) switches to mechanical hydraulic control as described above, and the vehicle is hydraulically driven by the brake pedal depression force. To be able to stop.

  The above is the basic operation of the power supply device according to the third embodiment, but actually, the same detailed operation as in the first embodiment is also performed.

  With the above-described configuration and operation, the in-vehicle auxiliary power supply 5 also monitors whether the fuel cell 10 can actually be operated and can generate electric power normally under the predetermined conditions. Thus, it was possible to generate electric power at 10 and an extremely reliable power supply device could be realized.

  In the third embodiment, the emergency power supply device for braking the vehicle is described as an example of the load 4. However, this may be an auxiliary power source for an abnormality in the battery for driving electrical equipment during idling stop of the idling stop vehicle. You may apply to the power supply device as an auxiliary power supply of the in-vehicle system.

  Further, the hydrogen tank 11 containing the hydrogen storage alloy may be used in the first and second embodiments. However, since the hydrogen generated in the hydrogen generator 13 contains water vapor from the pure water 20, if the hydrogen tank 11 containing the hydrogen storage alloy is filled as it is, the water vapor contained in the hydrogen and the surface of the hydrogen storage alloy It reacts and the hydrogen storage capacity deteriorates. Therefore, in this case, it is necessary to provide a dehumidifier in the middle of the filling piping path. When using a reformer, a hydrogen purifier composed of a palladium membrane or the like that extracts only hydrogen in the reformed gas is also required for the same reason as described above.

  Since the power supply device according to the present invention has a highly reliable power supply device configuration for determining the abnormality of the fuel cell so that it can be reliably operated when the main power supply is abnormal, it is particularly suitable for an uninterruptible power supply system or a vehicle load. Useful for power backup.

1 is a block configuration diagram of a power supply device according to Embodiment 1 of the present invention. Sectional drawing of the hydrogen generation part of the power supply device in Embodiment 1 of this invention The flowchart which shows operation | movement of the power supply device in Embodiment 1 of this invention. Block configuration diagram of a power supply device according to Embodiment 2 of the present invention The flowchart which shows operation | movement of the power supply device in Embodiment 2 of this invention. Block diagram of a power supply device according to Embodiment 3 of the present invention Sectional drawing of the hydrogen generation part of the power supply device in Embodiment 3 of this invention The flowchart which shows operation | movement of the power supply device in Embodiment 3 of this invention. Correlation diagram of the current supplied to the hydrogen generator with respect to the temperature of the hydrogen generator as the fuel cell abnormality detection drive condition of the power supply device in Embodiment 3 of the present invention Block diagram of a conventional power supply

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main power supply 4 Load 5 Auxiliary power supply 7 Control part 9 Power storage part 10 Fuel cell 11 Hydrogen tank 12 Pressure sensor 13 Hydrogen generation part 18 Oxygen pipe 19 Hydrogen pipe 20 Pure water 21 Water amount upper limit sensor 23 Partition plate 24 Water electrolysis element 25 Opening part 26 Temperature Sensor 27 Constant Current Source 29 Constant Current Load 33 Sponge Resin

Claims (18)

Load,
A main power supply for supplying power to the load;
When an abnormality occurs in which the main power supply becomes a predetermined voltage or less, an auxiliary power supply that supplementarily supplies power to the load is formed.
The auxiliary power is
A fuel cell for supplying power to the load when the main power source is below a predetermined voltage;
A power storage unit that supplies power to the load until the fuel cell is started,
A control unit for controlling the entire auxiliary power source;
A hydrogen tank for supplying hydrogen to the fuel cell;
A hydrogen generation part for generating hydrogen,
The control unit supplies the hydrogen to the fuel cell when the main power supply is normal and at a predetermined condition,
By generating the fuel cell under predetermined conditions,
A power supply apparatus for determining an abnormality of the fuel cell. The power supply device according to claim 1, wherein hydrogen is supplied from a hydrogen tank when fuel cell abnormality is determined. The power supply device according to claim 2, wherein the hydrogen tank is replenished from the hydrogen generator to the hydrogen tank after the fuel cell abnormality is judged. The power supply device according to claim 1, wherein hydrogen is supplied from a hydrogen generator when an abnormality is determined in the fuel cell. The power supply apparatus according to claim 1, wherein the abnormality determination of the fuel cell is detected by a voltage across the fuel cell when a constant current load is connected in a state where hydrogen and air are supplied to the fuel cell. The power supply device according to claim 1, wherein a water electrolysis element is provided inside the hydrogen generation unit, and hydrogen is generated by passing a current from a constant current source through the water electrolysis element submerged in pure water. The constant current source has a built-in current sensor, and the output of the current sensor is connected to the control unit,
The power supply device according to claim 6, wherein the control unit does not determine the abnormality of the fuel cell unless the output of the current sensor reaches a predetermined current when determining the abnormality of the fuel cell. The power generation device according to claim 6, wherein the hydrogen generation unit is provided with a water amount upper limit sensor, and water is always supplied to a position of the water amount upper limit sensor. Inside the hydrogen generation part has a sponge-like resin arranged on both sides partitioned by a water electrolysis element,
And stored in a state where water is impregnated in the sponge-like resin,
The power supply device according to claim 6, wherein a hydrogen pipe and an oxygen pipe respectively attached to portions partitioned by the water electrolysis element have a length up to a position not in contact with the sponge-like resin. The water electrolysis element is integrally formed with a partition plate for partitioning the inside of the hydrogen generation part, and an opening is provided in the partition plate near the bottom of the hydrogen generation part, and only the water electrolysis element located in the opening is a sponge. The power supply device according to claim 9, which is in contact with the resin-like resin. The power supply device according to claim 9, wherein the sponge-like resin arranged on the hydrogen tube side is smaller than the sponge-like resin arranged on the oxygen tube side. The hydrogen generation unit is provided with a temperature sensor, and if the output of the temperature sensor is below a predetermined temperature at the time of judging the abnormality of the fuel cell, the abnormality of the fuel cell is not judged and the abnormality is not detected until the temperature becomes higher than the predetermined temperature. The power supply device according to claim 6, wherein the determination is performed. The power supply device according to claim 12, wherein the current value of the constant current load is determined according to the output of the temperature sensor. 2. The power supply device according to claim 1, wherein if the main power source becomes abnormal during determination of abnormality of the fuel cell, the determination of abnormality of the fuel cell is immediately stopped. The power supply device according to claim 1, wherein the heat generating circuit component is disposed in contact with an outer surface of the hydrogen generation unit. The hydrogen tank is provided with a pressure sensor for detecting an internal pressure, and when the output of the pressure sensor is equal to or lower than a predetermined value, the hydrogen tank is replenished with hydrogen generated in the hydrogen generation unit when the main power supply is normal. The power supply device according to 1. The power supply device according to claim 1, wherein a hydrogen storage alloy made of an alloy containing a rare earth is incorporated in the hydrogen tank. The power supply device according to claim 17, wherein the hydrogen tank is disposed in the vicinity of the fuel cell.

Images