Hydrogen production system, hydrogen production method, and program

Abstract

To provide a hydrogen production system, a hydrogen production method, and a program that can continuously produce a sufficient amount of hydrogen. [Solution] The hydrogen production system 1 comprises an electrolytic device 2, a plurality of power converters 3 that convert three-phase AC power into DC power and supply DC power to the electrolytic device 2, and a control device 4 that controls the power converters. The plurality of power converters 3 are connected to the electrolytic device 2 in parallel with each other. The control device 4 is configured to correct at least one of the voltage and current of the power converters 3 that continue to supply power to the electrolytic device 2 so that the amount of hydrogen produced by the electrolytic device 2 thereafter reaches a predetermined target amount when the power supply from some of the power converters 3 to the electrolytic device 2 stops.

Description

[Technical Field]

[0001] The present invention relates to a hydrogen production system, a hydrogen production method, and a program. [Background Art]

[0002] As an apparatus for producing hydrogen, there is a hydrogen production system that generates hydrogen by electrolyzing a raw material such as water. Such a hydrogen production system includes, for example, as described in Patent Document 1, an electrolytic cell stack for electrolyzing a raw material to take out hydrogen, and a power source that supplies electric power to the electrolytic cell stack. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent No. 6704998 [Summary of the Invention] [Problems to be Solved by the Invention]

[0004] However, such a hydrogen production system has the following problems. That is, when electric power is actually supplied from a power source to an electrolytic cell stack, for example, AC power supplied from an AC power source is converted into DC power by a power converter. When an abnormality is detected in the power converter or the power converter needs to be replaced, and thus the power supply from the power converter to the electrolytic cell stack is stopped, the entire hydrogen production system has to be stopped. That is, there is a problem that hydrogen generation cannot be continued.

[0005] The present invention has been made in view of such problems, and an object of the present invention is to provide a hydrogen production system and a hydrogen production method capable of continuing sufficient hydrogen generation. [Means for Solving the Problems]

[0006] One aspect of the present invention is an electrolytic apparatus (2, 21, 22, 23) that generates hydrogen by electrolyzing a raw material, Multiple power converters (3, 31, 32, 33, 34, 35, 36, 37, 38, 39) convert three-phase AC power into DC power and supply the DC power to the electrolytic device, The system includes a control device (4) for controlling the power converter, Multiple power converters are connected to the electrolytic device in parallel with each other. The control device is located in a hydrogen production system (1) and is configured to correct at least one of the voltage and current of the power converters that continue to supply power to the electrolytic device, so that when the power supply from some of the power converters to the electrolytic device is stopped, the amount of hydrogen produced by the electrolytic device thereafter reaches a predetermined target amount.

[0007] Another aspect of the present invention is a hydrogen production system (1) comprising an electrolytic apparatus (2, 21, 22, 23) that electrolyzes a raw material to produce hydrogen, and a plurality of power converters (3, 31, 32, 33, 34, 35, 36, 37, 38, 39) that convert three-phase AC power into DC power and supply the DC power to the electrolytic apparatus, wherein the electrolytic apparatus is connected to a plurality of the power converters connected in parallel with each other, and the hydrogen is produced by this hydrogen production system (1). The hydrogen production method includes, in the event that the power supply to the electrolytic device from some of the power converters among the multiple power converters stops, correcting at least one of the voltage and current of the power converters that continue to supply power to the electrolytic device so that the amount of hydrogen produced by the electrolytic device thereafter reaches a predetermined target amount, and setting the corrected value to the corrected value.

[0008] A further aspect of the present invention is a program for controlling the control device of a hydrogen production system comprising an electrolytic apparatus (2, 21, 22, 23) that electrolyzes a raw material to produce hydrogen, a plurality of power converters (3, 31, 32, 33, 34, 35, 36, 37, 38, 39) that convert three-phase AC power into DC power and supply the DC power to the electrolytic apparatus, and a control device (4) that controls the power converters, wherein the electrolytic apparatus is connected to a plurality of the power converters connected in parallel with each other. The control device is programmed to correct at least one of the voltage and current of the power converters that continue to supply power to the electrolytic device, so that when the power supply from some of the power converters to the electrolytic device is stopped, the amount of hydrogen produced by the electrolytic device thereafter reaches a predetermined target amount. [Effects of the Invention]

[0009] In the hydrogen production system described above, the electrolytic device is connected to multiple power converters that are connected in parallel to each other. This allows power to continue to be supplied to the electrolytic device from other power converters even if the power supply from some power converters to the electrolytic device is stopped.

[0010] Furthermore, the control device is configured to correct at least one of the voltages and currents of the power converters that continue to supply power to the electrolytic device, so that if the power supply from some of the power converters to the electrolytic device stops, the amount of hydrogen produced by the electrolytic device thereafter reaches a predetermined target amount. Therefore, even if the power supply from some of the power converters to the electrolytic device stops, the power supplied to the electrolytic device by the power converters that continue to supply power can compensate for the decrease in the amount of hydrogen produced by the entire hydrogen production system. In other words, a hydrogen production system that can continue to produce sufficient hydrogen can be obtained.

[0011] Further, according to the hydrogen production method described above, even if power supply from some of the power converters to the electrolysis device is stopped, the amount of hydrogen produced can be compensated. In other words, a hydrogen production method capable of continuing sufficient hydrogen production can be obtained.

[0012] As described above, according to the above aspect, a hydrogen production system, a hydrogen production method, and a program that can continue sufficient hydrogen production can be provided. Note that the reference numerals in parentheses described in the claims and the means for solving the problems indicate the corresponding relationship with the specific means described in the embodiments below, and do not limit the technical scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] [Figure 1] An explanatory diagram of the hydrogen production system in Embodiment 1. [Figure 2] A control flow diagram in Embodiment 1. [Figure 3] A diagram showing an example of temporal changes in current of a plurality of power converters in Embodiment 1. [Figure 4] An explanatory diagram of the hydrogen production system in Embodiment 2. [Figure 5] A control flow diagram in Embodiment 2. [Figure 6] A diagram showing an example of temporal changes in hydrogen production amount of a plurality of electrolysis devices in Embodiment 2. [Figure 7] A control flow diagram in Embodiment 3. [Figure 8] A diagram showing an example of temporal changes in hydrogen production amount of a plurality of electrolysis devices in Embodiment 3. [Figure 9] An explanatory diagram of the hydrogen production system in Embodiment 4. [Figure 10] An explanatory diagram of the hydrogen production system while some electrolysis devices are stopped in Embodiment 4. [Figure 11] A control flow diagram in Embodiment 4. [Figure 12] A circuit explanatory diagram of the power converter in Embodiment 5. [Figure 13] Circuit explanatory diagram of the power converter in Embodiment 6. MODE FOR CARRYING OUT THE INVENTION

[0014] (Embodiment 1) Embodiments related to a hydrogen production system, a hydrogen production method, and a program will be described with reference to FIGS. 1 to 3. As shown in FIG. 1, the hydrogen production system 1 of the present embodiment includes an electrolysis device, a plurality of power converters 3, a control device 4, and power supply wirings 5 and 50. The power converter 3 of the hydrogen production system 1 is connected to a three-phase AC power supply 11.

[0015] The electrolysis device 2 electrolyzes a raw material to generate hydrogen. The plurality of power converters 3 convert three-phase AC power into DC power and supply the DC power to the electrolysis device 2. The control device 4 controls the power converters 3. A plurality of power converters 3 connected in parallel to each other are connected to the electrolysis device 2.

[0016] The control device 4 is configured to, when power supply from some of the plurality of power converters 3 to the electrolysis device 2 is stopped, correct at least one of the voltage and current of the power converter 3 that continues power supply to the electrolysis device 2 to obtain a corrected value, so that the subsequent hydrogen production amount of the electrolysis device 2 becomes a predetermined target amount. In the present embodiment, while power supply from some of the power converters 3 to the electrolysis device 2 is stopped, at least one of the voltage and current of the power converter 3 that continues power supply to the electrolysis device 2 is set to the corrected value in advance.

[0017] Note that, unless otherwise specified, the "voltage of the power converter 3" means the voltage of DC power output from the power converter 3, and the "current of the power converter 3" means the current of DC power output from the power converter 3. Unless otherwise specified, the hydrogen production amount of the electrolysis device 2 means the amount of hydrogen produced by the electrolysis device 2 per unit time.

[0018] In this embodiment, as shown in Figure 1, the hydrogen production system 1 will be described in a case where it has one electrolytic device 2 and three power converters 31, 32, and 33. However, the number of power converters 3 connected in parallel to each other is not particularly limited.

[0019] The three power converters 31, 32, and 33 are connected in parallel to each other. This parallel configuration of the three power converters 31, 32, and 33 is connected to the electrolytic device 2. Furthermore, the three power converters 31, 32, and 33 are connected to a three-phase AC power supply 11. Power converter 3 converts the three-phase AC power into DC power. This converted DC power is then supplied to the electrolytic device 2.

[0020] Each of the three power converters 31, 32, and 33 is connected to the electrolytic device 2 by power supply wiring 5 and 50. Power supply wiring 5 is the wiring on the high potential side, and power supply wiring 50 is the wiring on the low potential side. Power supply wiring 5 has a common wiring 54 connected to the electrolytic device 2, and three branch wirings 51 that branch off from the common wiring 54 and are connected to each of the three power converters 31, 32, and 33. Each of the three branch wirings 51 is provided with a relay 52. ​​That is, each power converter 31, 32, and 33 can switch between disconnecting and connecting to the electrolytic device 2 by opening and closing the relay 52. ​​Under normal conditions, these relays 52 are in the ON state. The relays 52 can be configured as, for example, electromagnetic relays.

[0021] Furthermore, the power supply wiring 50, like the power supply wiring 5, has a common wiring 540 connected to the electrolytic device 2, and three branch wirings 510 that branch off from the common wiring 540 and are connected to the three power converters 31, 32, and 33, respectively.

[0022] Furthermore, current sensors 53 are provided in each of the branch wirings 51 and 510 of the power supply wirings 5 ​​and 50. In other words, each current sensor 53 can detect the current output from each power converter 3.

[0023] The electrolytic device 2 has a cell stack formed by stacking multiple electrolytic cells 20. In this embodiment, the electrolytic cells 20 are SOECs (i.e., Solid Oxide Electrolysis Cells). Each electrolytic cell 20 has an air electrode and a hydrogen electrode, and further comprises an electrolyte interposed between the hydrogen electrode and the air electrode. Multiple electrolytic cells 20 are connected in series to form a cell stack.

[0024] In this configuration, a gas containing water vapor is supplied to the hydrogen electrode, and air is supplied to the air electrode. In other words, water as a raw material is supplied to the hydrogen electrode in the form of water vapor. The water vapor is introduced into the electrolytic device 2 through the raw material supply channel 121 and supplied to the hydrogen electrode of each electrolytic cell 20. The air is introduced into the electrolytic device 2 through the air supply channel 131 and supplied to the air electrode of each electrolytic cell 20.

[0025] The electrolyte of electrolytic cell 20 is made of solid oxide ceramic, and oxide ions (O 2- It has conductivity of ). The electrolyte can be made using, for example, yttria-stabilized zirconia, perovskite-type oxide, etc. Then, the electrolyte is heated to a high temperature, for example, 600°C to 800°C, and electricity is supplied between the air electrode and the hydrogen electrode to cause an electrolytic reaction of water vapor. This produces hydrogen at the hydrogen electrode and oxygen at the oxygen electrode.

[0026] In other words, the water vapor supplied to the electrolytic cell 20 reacts at the hydrogen electrode with "H2O + 2e - →H2+O 2- The electrolytic reaction of "" takes place at the air electrode. 2- → 1 / 2O2 + 2e - The following reaction takes place: At the hydrogen electrode, water vapor is electrolyzed, producing hydrogen gas and oxide ions (O 2- Oxide ions are produced. These oxide ions move through the electrolyte to the air electrode, where they are oxidized to oxygen gas.

[0027] The hydrogen-containing gas produced by this electrolytic reaction is discharged from the hydrogen electrode to the outside of the electrolytic cell 20 and out of the electrolytic device 2 through the hydrogen discharge channel 122. The oxygen-containing gas produced is also discharged from the air electrode to the outside of the electrolytic cell 20 and out of the electrolytic device 2 through the air discharge channel 132.

[0028] In this configuration, the power converter 3 supplies power to the electrolytic device 2. Specifically, the power converter 3 converts the three-phase AC power supplied from the three-phase AC power source 11 into DC power and supplies the DC power to the cell stack of the electrolytic device 2. This DC power is supplied between the air electrode and the hydrogen electrode of each electrolytic cell 20, as described above.

[0029] The control device 4 includes a microcomputer equipped with a processor, memory, and other peripheral circuits. The control device 4 may be composed of multiple microcomputers and their peripheral devices. The control device 4 controls the drive of the power converters 3. That is, the control device 4 controls at least one of the currents and voltages of the multiple power converters 3. In this embodiment, the control device 4 controls the current of the power converters 3. More specifically, the control device 4 is configured to correct at least one of the voltages and currents of the power converters 3 that continue to supply power to the electrolytic device 2 so that the amount of hydrogen produced by the electrolytic device 2 reaches a predetermined target amount while the power supply from some of the multiple power converters 3 to the electrolytic device 2 is stopped.

[0030] The control device 4 determines whether the power supply from some of the power converters 3 to the electrolytic device 2 has been stopped. Whether the power supply from some of the power converters 3 to the electrolytic device 2 has been stopped can be determined, for example, based on the detected value of the current sensor 53.

[0031] Furthermore, the control device 4 can also control the opening and closing of the relay 52. ​​For example, when an abnormality is detected in one of the power converters 31 among the multiple power converters 3, the control device 4 opens the relay 52 provided in the branch wiring 51 connected to the power converter 31, thereby stopping the power supply from the power converter 31 to the electrolytic device 2. An abnormality in a power converter 31 can be detected, for example, based on the detected value of the current sensor 53. Examples of abnormalities in a power converter include output overvoltage and output overcurrent, and these abnormalities can be detected by voltage sensors, current sensors, etc.

[0032] When the power supply from some of the power converters 31 to the electrolytic device 2 is stopped, the power supply from the other power converters 32 and 33 to the electrolytic device 2 is increased. Specifically, the current flowing from the other power converters 32 and 33 to the electrolytic device 2 is increased. This makes it possible to compensate for the decrease in hydrogen production due to the stopping of some of the power converters 31 by increasing the amount of hydrogen produced by the increased output of the other power converters 32 and 33, thereby maintaining the amount of hydrogen produced in the electrolytic device 2 at a predetermined target amount.

[0033] Alternatively, when replacing some of the power converters 31, it is possible to open some of the relays 52 to stop the power supply from the power converters 31 to the electrolyzer 2. For example, to prevent malfunctions in the power converters 31, they may be replaced with new ones after a predetermined period of operation. In this case, the power converters 31 will be disconnected from the hydrogen production system 1. In this case as well, the power supply from the other power converters 32 and 33 to the electrolyzer 2 will be increased to maintain the amount of hydrogen produced in the electrolyzer 2 at a predetermined target amount.

[0034] An example of a specific control method performed by the control device 4 will be explained using the flowchart in Figure 2. First, in step S1, it is determined whether it has become necessary to stop the power supply from any of the power converters 3 to the electrolytic device 2. This determination is made, for example, by determining whether an abnormality has occurred in any of the power converters 3 and whether a replacement will be performed, as described above. For example, whether an abnormality has occurred in a power converter 3 can be determined by whether the control device 4 has received an abnormality detection signal from the power converter 3, or by the current value detected by the current sensor 53 described above. Furthermore, whether a power converter 3 will be replaced can be determined, for example, by determining whether a signal indicating that the power converter 3 is being replaced is input to the control device 4 from an external source in conjunction with the operation of a replacement worker or other person during the replacement.

[0035] In step S1, if it is determined that it is necessary to stop the power supply from any of the power converters 3 (e.g., power converter 31) to the electrolytic device 2, the power converter 3 (e.g., power converter 31) is disconnected from the electrolytic device 2 (step S2). That is, the relay 52 provided on the output side of the power converter 3 (e.g., power converter 31) is switched off.

[0036] Next, the target amount of hydrogen to be produced in the electrolytic device 2 (referred to as "target hydrogen production amount" as appropriate) is obtained (step S3). The target hydrogen production amount can be obtained, for example, by reading information on the target amount of hydrogen stored in the memory of the control device 4, or by obtaining it from an external device of the hydrogen production system 1. This target hydrogen production amount can be, for example, equivalent to the amount of hydrogen that was normally produced by the electrolytic device 2 before some of the power converters 3 (e.g., power converter 31) were disconnected from the electrolytic device 2. Alternatively, the target hydrogen production amount may be less than the amount of hydrogen that was normally produced by the electrolytic device 2 before some of the power converters 3 (e.g., power converter 31) were disconnected from the electrolytic device 2, and more than the amount of hydrogen that the electrolytic device 2 was producing with the power supplied by the power converters 3 other than the power converter 3 that is being shut off (e.g., power converters 32, 33). More specifically, in this embodiment, the target hydrogen production amount may be set to an amount less than the amount of hydrogen that the electrolytic device 2 would have produced with the total power supplied by the three power converters 31, 32, and 33, and greater than the amount of hydrogen that the electrolytic device 2 would have produced with the total power supplied by the two power converters 32 and 33 that continue to operate. Either target hydrogen production amount can be set as a target value to suppress the decrease in the amount of hydrogen produced by the hydrogen production system 1 when some of the power converters 3 stop.

[0037] Based on the acquired target hydrogen production amount, the current to be supplied to the electrolytic device 2 is calculated (step S4). The output current of each power converter 3 (for example, power converters 32 and 33) is corrected so that the current supplied to the electrolytic device 2 is the current calculated in step S4 (step S5). Then, power supply from the power converters 3 (for example, power converters 32 and 33) to the electrolytic device 2 is continued with this corrected current value (i.e., the corrected value). Power supply with the corrected current continues until the power converter 3 (for example, power converter 31) that had stopped supplying power is restored (step S6).

[0038] Here, "the power converter 3 is restored" means that the power converter 3 is able to supply power normally, or that the replacement of the power converter 3 with a new power converter 3 is completed.

[0039] Then, in step S6, when it is determined that the power converter 3 (for example, power converter 31) has been restored, the restored power converter 3 (for example, power converter 31) is reconnected to the electrolytic device 2. That is, for example, relay 511 is turned on. At the same time, in step S8, the output currents of the three power converters 31, 32, and 33 are returned to their pre-correction values, and power supply is continued (step S8). Then, the control flow is returned to step S1.

[0040] Figure 3 shows an example of how the current supplied from the three power converters 31, 32, and 33 to the electrolytic device 2 is changed. For example, when power converter 31 is stopped between time t1 and t2, the current values ​​of power converters 32 and 33 during this period are increased to be greater than the normal current values. When power converter 32 is stopped between time t3 and t4, the current values ​​of power converters 31 and 33 during this period are increased to be greater than the normal current values. When power converter 33 is stopped between time t5 and t6, the current values ​​of power converters 31 and 32 during this period are increased to be greater than the normal current values. Here, "normal" means when the three power converters 3 are operating normally.

[0041] In this way, even if the power supply from one of the power converters 3 (for example, power converter 31) is stopped, the decrease in the total current supplied to the electrolytic device 2 can be suppressed by increasing the current from the other power converters 3 (for example, power converters 32 and 33). As a result, even if the power supply from one of the power converters 3 (for example, power converter 31) is stopped, hydrogen production can be continued while maintaining the amount of hydrogen produced in the electrolytic device 2 at a predetermined target amount.

[0042] Next, the effects and benefits of the hydrogen production system 1 and hydrogen production method of this embodiment will be explained. In the hydrogen production system 1 described above, the electrolytic device 2 is connected to a plurality of power converters 3 that are connected in parallel to each other. As a result, even if the power supply from some of the power converters 3 (for example, power converter 31) to the electrolytic device 2 is stopped, the power supply from the other power converters 3 (for example, power converters 32, 33) to the electrolytic device 2 can continue.

[0043] Furthermore, the control device 4 is configured to correct the current of the power converters 3 (e.g., power converters 32, 33) that continue to supply power to the electrolytic device 2 so that the amount of hydrogen produced by the electrolytic device 2 reaches a predetermined target amount, even when the power supply from some of the power converters 3 (e.g., power converter 31) to the electrolytic device 2 is stopped. Therefore, even if the power supply from some of the power converters 3 (e.g., power converter 31) to the electrolytic device 2 is stopped, the power supplied to the electrolytic device 2 can be supplemented by the power converters that continue to supply power (e.g., power converter 31), thereby suppressing the decrease in the amount of hydrogen produced by the entire hydrogen production system and maintaining the amount of hydrogen produced at a predetermined target amount. In other words, a hydrogen production system 1 can be obtained that can suppress the decrease in the amount of hydrogen produced due to the cessation of power supply from some of the power converters 3 to the electrolytic device 2 and continue to produce a sufficient amount of hydrogen.

[0044] Furthermore, according to the above hydrogen production method, even if the power supply from some of the power converters 3 (for example, power converter 31) to the electrolytic device 2 is stopped, the amount of hydrogen produced can be maintained at a predetermined target amount. In other words, a hydrogen production method that can continue to produce sufficient hydrogen can be obtained.

[0045] As described above, this embodiment provides a hydrogen production system, a hydrogen production method, and a program that can continuously produce sufficient hydrogen.

[0046] (Embodiment 2) As shown in Figures 4 to 6, the hydrogen production system 1 in this configuration has multiple electrolytic devices 2. Multiple power converters 3 are connected in parallel to each of the multiple electrolytic devices 2. The control device 4 is configured to correct at least one of the voltages or currents of the multiple power converters 3 so that the total amount of hydrogen produced by the multiple electrolytic devices 2 reaches a predetermined target amount.

[0047] In this embodiment, as shown in Figure 4, we will describe an example in which the hydrogen production system 1 has three electrolytic devices 21, 22, and 23, and three power converters 3 are connected to each of the electrolytic devices 21, 22, and 23. However, the number of power converters 3 connected in parallel to each other is not particularly limited.

[0048] Specifically, as shown in Figure 4, three power converters 31, 32, and 33 are connected to the electrolytic device 21, three power converters 34, 35, and 36 are connected to the electrolytic device 22, and three power converters 37, 38, and 39 are connected to the electrolytic device 23.

[0049] The control device 4 controls the nine power converters 3. The power converters 3 receive signals from current sensors that detect the current of each power converter 3, and send control signals to relays 52 installed between each power converter 3 and the electrolytic device 2. These signal lines and current sensors are omitted from the diagram in Figure 4.

[0050] An example of a specific control method for the control device 4 in this embodiment will be explained using the flowchart in Figure 5. First, in step S21, it is determined whether or not it has become necessary to stop the power supply from any of the power converters 3 to the electrolyzer 2.

[0051] In step S21, if it is determined that it is necessary to stop the power supply from any of the power converters 3 (e.g., power converter 31) to the electrolytic device 2, the power converter 3 (e.g., power converter 31) is disconnected from the electrolytic device 2 (step S22). That is, the relay 52 provided on the output side of the power converter 3 (e.g., power converter 31) is shut off.

[0052] Next, the sum of the target amounts of hydrogen produced by the three electrolyzers 2 (referred to as the "target total hydrogen production amount") is obtained (step S23). This target amount can be, for example, equivalent to the total amount of hydrogen produced by the three electrolyzers 2 before some of the power converters 3 (e.g., power converter 31) are disconnected from the electrolyzers 2. Then, based on this target total hydrogen production amount, the target hydrogen production amount for each electrolyzer 2 is calculated (step S24).

[0053] For example, if the power converter 31 stops, the target hydrogen production amounts for each electrolytic device 21, 22, and 23 can be calculated so that the decrease in hydrogen production by the electrolytic device 21 due to the stoppage of the power converter 31 is compensated for by the increase in hydrogen production by the electrolytic devices 22 and 23. This example may be referred to as Calculation Example 1.

[0054] Alternatively, the target hydrogen production amount of the electrolytic device 21 could be set so as to limit the decrease in hydrogen production by the electrolytic device 21 due to the shutdown of the power converter 31 to less than one-third, and the target hydrogen production amounts of the other electrolytic devices 22 and 23 could be set so as to compensate for any shortfall.

[0055] Alternatively, the target hydrogen production amount can be calculated so as to maintain the hydrogen production amount of the electrolytic device 21 at the same level as before the power converter 31 was shut down. In this case, there is no need to change the target hydrogen production amounts of each electrolytic device 21, 22, and 23. Furthermore, the method for determining the target hydrogen production amounts of each electrolytic device 21, 22, and 23 is not limited to these methods, and various other methods can be employed.

[0056] Based on the acquired target hydrogen production amount, the current to be supplied to each electrolytic device 21, 22, and 23 is calculated (step S25). The current of each power converter 3 (for example, power converters 32 to 39) is corrected so that the current supplied to each electrolytic device 2 is the current calculated in step S25 (step S26). Then, power supply from power converter 3 (for example, power converters 32 to 39) to electrolytic devices 21, 22, and 23 is continued with this corrected current value. Power supply with the corrected current continues until power converter 3 (for example, power converter 31) that had stopped supplying power is restored (step S27).

[0057] Then, in step S27, when it is determined that the power converter 3 (for example, power converter 31) has been restored, the restored power converter 3 (for example, power converter 31) is reconnected to the electrolytic device 21 (step S28). That is, the relay 52 on the output side of the restored power converter 3 is turned on. At the same time, in step S29, the currents of the nine power converters 31 to 39 are returned to their pre-correction values, and power supply is continued. Then, the control flow returns to step S21.

[0058] Figure 6 shows an example of how to change the target hydrogen production amount for the three electrolytic devices 21, 22, and 23. This example is based on the method for determining the target hydrogen production amount using Calculation Example 1 described above. In other words, for example, if the power converter 31 is stopped between times t21 and t22, the amount of hydrogen produced by the electrolytic device 21 decreases. During this time, the target hydrogen production amounts of the other electrolytic devices 22 and 23 are increased. This allows hydrogen production to continue while maintaining the total amount of hydrogen produced by the three electrolytic devices 21, 22, and 23 at the target amount.

[0059] Otherwise, it is the same as in Embodiment 1. Note that, among the reference numerals used in Embodiment 2 and later, those that are the same as those used in the previously described embodiments represent the same components, etc., as in the previously described embodiments, unless otherwise specified.

[0060] In this configuration, if the power supply from one power converter 3 is interrupted, there are more variations in how the decrease in the total amount of hydrogen produced can be suppressed. Therefore, the redundancy of the entire system can be further improved. Furthermore, it has the same effects and advantages as Embodiment 1.

[0061] (Embodiment 3) The hydrogen production system 1 in this embodiment also has multiple electrolytic devices 2. The system configuration itself in this embodiment is the same as that shown in Figure 4 of Embodiment 2. In this embodiment, as shown in Figures 7 and 8, the method of control by the control device 4 differs from that of Embodiment 2.

[0062] If the operation of some of the electrolytic devices 2 (e.g., electrolytic device 21) among the multiple electrolytic devices 2 is stopped, at least one of the voltages and currents of the multiple power converters 3 (e.g., power converters 34-39) is corrected so that the total amount of hydrogen produced by the other electrolytic devices 2 (e.g., electrolytic devices 22, 23) that continue to operate reaches a predetermined target amount. In this embodiment, while the operation of some of the electrolytic devices 2 (e.g., electrolytic device 21) is stopped, at least one of the voltages and currents of the power converters 3 is set to at least one of the corrected voltages and currents (i.e., the corrected value).

[0063] An example of a specific control method for the control device 4 in this embodiment will be explained using the flowchart in Figure 7. First, in step S31, it is determined whether or not it is necessary to stop the operation of some of the electrolytic devices 2 (for example, electrolytic device 21).

[0064] In step S31, if it is determined that it is necessary to stop the operation of any of the electrolytic devices 2 (e.g., electrolytic device 21), the electrolytic device 2 (e.g., electrolytic device 21) is disconnected from the multiple power converters 3 (e.g., power converters 31, 32, 33) (step S32). That is, the relay 52 between the electrolytic device 2 (e.g., electrolytic device 21) and the power converters 3 (e.g., power converters 31, 32, 33) is shut off.

[0065] Next, the total target amount of hydrogen produced by the two electrolyzers 2 that continue to operate (e.g., electrolyzers 22 and 23) is obtained (step S33). This target amount can be, for example, equivalent to the total amount of hydrogen produced by the three electrolyzers 2 immediately before some of the electrolyzers 2 (e.g., electrolyzer 21) are disconnected. Then, the target amount of hydrogen produced by each of the two electrolyzers 2 that continue to operate (e.g., electrolyzers 22 and 23) is calculated (step S34).

[0066] Based on the acquired target hydrogen production amount, the current to be supplied to each electrolytic device 2 (e.g., electrolytic devices 22 and 23) is calculated (step S35). The output current of each power converter 3 (e.g., power converters 34 to 39) is corrected so that the current supplied to each electrolytic device 2 is the current calculated in step S35 (step S36). Then, power supply from power converter 3 (e.g., power converters 34 to 39) to electrolytic devices 22 and 23 is continued with this corrected current value (i.e., corrected value). Power supply with the corrected current continues until the electrolytic device 2 that was stopped (e.g., electrolytic device 21) is restored (step S37). Note that "electrolytic device 2 is restored" means that the electrolytic device 2 is in a state where normal hydrogen production is possible, or that the replacement of the electrolytic device 2 with a new electrolytic device 2 is completed.

[0067] Then, in step S37, when it is determined that the electrolytic device 2 (e.g., electrolytic device 21) has recovered, the recovered electrolytic device 2 (e.g., electrolytic device 21) is reconnected to the three power converters 3 (e.g., power converters 31, 32, and 33) (step S38). That is, the relay 52 between the recovered electrolytic device 2 (e.g., electrolytic device 21) and the power converters 3 (e.g., power converters 31, 32, and 33) is turned on. At the same time, in step S39, the output currents of the nine power converters 31 to 39 are returned to their pre-correction values, and power supply is continued. Then, the control flow is returned to step S31.

[0068] Figure 8 shows an example of how to change the target hydrogen production amount for the three electrolytic devices 21, 22, and 23. In other words, for example, if electrolyzer 21 is stopped between times t31 and t32, the amount of hydrogen produced by electrolyzer 21 will be zero. During this time, the target hydrogen production amounts of the other electrolyzers 22 and 23 are increased. This allows hydrogen production to continue while maintaining the total amount of hydrogen produced by the two electrolyzers 22 and 23 that continue to operate at the target amount. Other aspects are the same as in Embodiment 1.

[0069] In this configuration, even when the operation of some of the multiple electrolytic devices 2 is stopped, hydrogen production can be continued while maintaining the hydrogen production amount at the target level. Furthermore, it has the same effects and advantages as Embodiment 1.

[0070] Furthermore, it is also possible to have a system that performs both the control method shown in Embodiment 2 and the control method shown in Embodiment 3. That is, the system can be configured to perform the control method of Embodiment 2 when the power supply from some of the power converters 3 stops, and to perform the control method of Embodiment 3 when the operation of some of the electrolytic devices 2 stops.

[0071] (Embodiment 4) In this embodiment of the hydrogen production system 1, as shown in Figure 9, a switching relay 55 and a connecting wire 56 are provided in the power supply wiring 5 connected to each of the multiple electrolytic devices 2. Specifically, a switching relay 55 is provided on the common wiring 54 of the power supply wiring 5 connected to the electrolytic device 2. The other end of a connecting wiring 56, one end of which is connected to the common wiring 54 of another power supply wiring 5, is also connected to this switching relay 55. Normally, the switching relay 55 does not connect the connecting wiring 56 to the common wiring 54, but rather connects the path of the common wiring 54 as shown in Figure 9.

[0072] When hydrogen production by some of the electrolytic devices 2 (for example, electrolytic device 21) stops, the control device 4 switches the switching relay 55 connected to that electrolytic device 2 to the connecting wiring 56 side. Figure 10 shows this state. In the figure, arrow P represents the power supply path to electrolytic devices 22 and 23.

[0073] In other words, the power converter 3 that was connected to electrolytic device 2 (e.g., electrolytic device 21) is connected to one of the other electrolytic devices 2 (e.g., electrolytic device 22). Then, the currents of the multiple power converters 3 are corrected so that the total amount of hydrogen produced by the electrolytic devices 2 that continue to produce hydrogen (e.g., electrolytic devices 22, 23) reaches a predetermined target amount. In this embodiment, while hydrogen production by some of the electrolytic devices 2 (e.g., electrolytic device 21) is stopped, the switching relay 55 connected to that electrolytic device 2 is connected to the connecting wiring 56 side. During this time, the currents of the multiple power converters 3 are kept at the corrected value.

[0074] An example of a specific control method for this embodiment will be explained using the flowchart in Figure 11. First, in step S41, it is determined whether or not it is necessary to stop the operation of some of the electrolytic devices 2 (for example, electrolytic device 21).

[0075] In step S41, if it is determined that it is necessary to stop the operation of any of the electrolytic devices 2 (e.g., electrolytic device 21), the connection destination of the multiple power converters 3 (e.g., power converters 31, 32, 33) that were connected to the electrolytic device 2 (e.g., electrolytic device 21) is switched to another electrolytic device 2 (e.g., electrolytic device 22) (step S42). That is, the switching relay 55 between the electrolytic device 2 (e.g., electrolytic device 21) and the power converters 3 (e.g., power converters 31, 32, 33) is switched. This disconnects the power converters 3 (e.g., power converters 31, 32, 33) from the electrolytic device 2 (e.g., electrolytic device 21) and connects them to another electrolytic device 2. This allows, for example, power converters 31 to 36 to be connected to electrolytic device 22 (see Figure 10).

[0076] Next, the total target amount of hydrogen produced in the two electrolyzers 2 that continue to operate (e.g., electrolyzers 22 and 23) is obtained (step S43). Then, the target amount of hydrogen produced in each of the two electrolyzers 2 that continue to operate (e.g., electrolyzers 22 and 23) is calculated (step S44).

[0077] Based on the acquired target hydrogen production amount, the current to be supplied to each electrolytic device 2 (for example, electrolytic devices 22 and 23) is calculated (step S45). The current of each power converter 3 is corrected so that the current supplied to each electrolytic device 2 is the current calculated in step S45 (step S46).

[0078] Then, power supply from power converter 3 (for example, power converters 34-39) to electrolytic devices 22 and 23 continues at this corrected current value (i.e., the corrected value). Power supply with the corrected current continues until electrolytic device 2 (for example, electrolytic device 21), which had stopped operating, is restored (step S47).

[0079] Then, in step S47, when it is determined that the electrolytic device 2 (e.g., electrolytic device 21) has been restored, the restored electrolytic device 2 (e.g., electrolytic device 21) is reconnected to the three power converters 3 (e.g., power converters 31, 32, and 33) (step S48). That is, the switching relay 55 between the restored electrolytic device 2 (e.g., electrolytic device 21) and the power converters 3 (e.g., power converters 31, 32, and 33) is switched to the side of the restored electrolytic device 2 (e.g., electrolytic device 21) (see Figure 9). At the same time, in step S49, the output currents of the nine power converters 31 to 39 are returned to their pre-correction values, and power supply is continued. Then, the control flow returns to step S41. Otherwise, it is the same as in Embodiment 3.

[0080] In this configuration, even if hydrogen production in some of the electrolytic devices 2 is stopped, multiple power converters 3 can be effectively utilized. For example, if it is not possible to switch the connections of the power converters 3 while hydrogen production by the electrolytic device 21 is stopped, then power converters 31, 32, and 33 that were connected to the electrolytic device 21 cannot be used.

[0081] In contrast, in this embodiment, for example, if hydrogen production by the electrolytic device 21 is stopped, the power converters 31, 32, and 33 can be switched and connected to other electrolytic devices 22. Then, the power from power converters 31, 32, and 33 can be supplied to the electrolytic device 22 in addition to the power from power converters 34, 35, and 36. In this way, in this embodiment, the redundancy of the power supply can be improved while effectively utilizing multiple power converters 3. Furthermore, it has the same effects and advantages as Embodiment 3.

[0082] (Embodiment 5) In this embodiment, as shown in Figure 12, an example of the configuration of multiple power converters 3 provided in the hydrogen production system 1 will be described. In the figure, only one power converter 3 is shown, but the hydrogen production system 1 is equipped with multiple power converters 3, and the multiple power converters 3 are connected in parallel to each other. This point is the same as in Embodiment 1.

[0083] The power converter 3 includes a first power converter 3A that converts three-phase AC power to DC power, and a second power converter 3B that converts the DC power converted by the first power converter 3A to DC power of a different voltage. The first power converter 3A and the second power converter 3B are connected by a high-potential side wiring 63H and a low-potential side wiring 63L.

[0084] The first power conversion unit 3A has three or more legs (hereinafter referred to as "first legs 641") connected in parallel to each other between the high-potential side wiring 63H and the low-potential side wiring 63L. Each first leg 641 consists of an upper arm switch (hereinafter referred to as "first upper arm switch 651u") connected to the high-potential side wiring 63H and a lower arm switch (hereinafter referred to as "first lower arm switch 651d") connected to the low-potential side wiring 63L, connected in series.

[0085] The connection point between the first upper arm switch 651u and the first lower arm switch 651d in the first leg 641 is connected to the input wiring 601 into which three-phase AC power is input. A DC link capacitor 661 is connected between the high-potential side wiring 63H and the low-potential side wiring 63L between the first power conversion unit 3A and the second power conversion unit 3B.

[0086] The second power conversion unit 3B has a second leg 642 and a reactor 662 connected between the high-potential side wiring 63H and the low-potential side wiring 63L. The second leg 642 consists of a second upper arm switch 652u connected to the high-potential side wiring 63H and a second lower arm switch 652d connected to the low-potential side wiring 63L, connected in series. On the electrolytic device 2 side of the reactor 662, a filter capacitor 663 is connected between a pair of power supply wirings 5 ​​and 50.

[0087] Reactor 662 is connected between the connection point of the second upper arm switch 652u and the second lower arm switch 652d in the second leg 642 and the power supply wiring 5. The low-potential side wiring 63L is connected to the power supply wiring 50. Power supply wiring 5 is connected to the positive electrode of the electrolytic device 2, and power supply wiring 50 is connected to the negative electrode of the electrolytic device 2.

[0088] The input wiring 601 is connected to the supply wiring 151 for three-phase AC power from the three-phase AC power supply 11. The supply wiring 151 is provided with a precharge circuit 152 and a filter circuit 153. The precharge circuit 152 includes, for example, a switch and a resistor to prevent inrush current from flowing from the three-phase AC power supply 11 to the power converter 3. The filter circuit 153 includes, for example, an inductor and a capacitor to remove noise components from the three-phase AC power supplied from the three-phase AC power supply 11. The three-phase AC power supply 11 can be, for example, a power grid.

[0089] In the first power conversion unit 3A of the power conversion device 3, the input three-phase AC power is converted to DC power by appropriate switching operations of a plurality of first upper arm switches 651u and a plurality of first lower arm switches 651d. This DC power is charged to the DC link capacitor 661. Then, in the second power conversion unit 3B, this DC power is converted to DC power of an appropriate voltage by appropriate switching operations of the second upper arm switch 652u and the second lower arm switch 652d and output. This output DC power is supplied to the electrolytic device 2.

[0090] Each of the switches, the first upper arm switch 651u, the first lower arm switch 651d, the second upper arm switch 652u, and the second lower arm switch 652d, has a freewheeling diode connected in antiparallel. The switching operation of the first upper arm switch 651u, the first lower arm switch 651d, the second upper arm switch 652u, and the second lower arm switch 652d is controlled by a drive signal from the control device 4. The first upper arm switch 651u, the first lower arm switch 651d, the second upper arm switch 652u, and the second lower arm switch 652d can be constructed using, for example, IGBTs (i.e., insulated gate bipolar transistors), MOSFETs (MOS-type field-effect transistors), etc. Other aspects are the same as in Embodiment 1.

[0091] In this configuration, three-phase AC power can be easily converted to desired DC power. Furthermore, the power converter 3 can be a power converter for vehicles such as electric vehicles that has been adapted for use in the hydrogen production system 1. In other words, the vehicle power converter is connected between the vehicle's drive battery and drive motor. By connecting the electrolytic device 2 to the side where the drive battery is connected and the three-phase AC power supply 11 to the side where the drive motor is connected, the power converter can be used as a power converter for the hydrogen production system 1. Furthermore, it has the same effects and advantages as Embodiment 1.

[0092] (Embodiment 6) As shown in Figure 13, this embodiment is a variation of Embodiment 5 and is another example of the configuration of the multiple power converters 3 provided in the hydrogen production system 1. In this embodiment, the second power conversion unit 3B in the power conversion device 3 has a plurality of second legs 642. In particular, this embodiment shows an example in which the second power conversion unit 3B has three second legs 642.

[0093] Furthermore, output wires 643 are connected to the connection points of the second upper arm switch 652u and the second lower arm switch 652d in the three second legs 642. Two of these three output wires 643 are connected to the power supply wire 5, which is connected to the positive electrode of the electrolytic device 2, via the reactor 664. The remaining one of the three output wires 643 is idle.

[0094] Furthermore, the low-potential wiring 63L is connected to the power supply wiring 50, which is connected to the negative electrode of the electrolytic device 2, via the extraction wiring 631L. A filter capacitor 665 is connected between the power supply wiring 5 and the power supply wiring 50. Although the high-potential wiring 63H is also connected to the extraction wiring 631H, this extraction wiring 631H is idle wiring.

[0095] The second power conversion unit 3B converts DC power to DC power of an appropriate voltage and outputs it by the appropriate switching operation of multiple second upper arm switches 652u and multiple second lower arm switches 652d. However, the second upper arm switches 652u and second lower arm switches 652d of the second leg 642 to which the idle output wiring 643 is connected are not switched and are both left open (i.e., disconnected). Otherwise, it has the same configuration and effects as Embodiment 5.

[0096] In the above embodiment, a control method for correcting the current of the power converter was described, but it is also possible to use a control method for correcting the voltage of the power converter. Alternatively, it is also possible to use a control method for correcting both the voltage and current of the power converter.

[0097] The present invention is not limited to the embodiments described above, and can be applied to various embodiments without departing from its spirit.

[0098] The features of this invention are as follows. [1] Electrolytic devices (2, 21, 22, 23) that produce hydrogen by electrolyzing raw materials, Multiple power converters (3, 31, 32, 33, 34, 35, 36, 37, 38, 39) convert three-phase AC power into DC power and supply the DC power to the electrolytic device, The system includes a control device (4) for controlling the power converter, Multiple power converters are connected to the electrolytic device in parallel with each other. Hydrogen production system (1), wherein the control device is configured to correct at least one of the voltage and current of the power converters that continue to supply power to the electrolytic device, so that when the power supply from some of the power converters to the electrolytic device is stopped, the amount of hydrogen produced by the electrolytic device thereafter reaches a predetermined target amount. [2] The power converter includes a first power converter (3A) that converts the three-phase AC power into DC power, and a second power converter (3B) that converts the DC power converted by the first power converter into DC power of a different voltage, and the first power converter and the second power converter are connected by a high-potential side wiring (63H) and a low-potential side wiring (63L). The first power conversion unit has three or more legs (641) connected in parallel to each other between the high-potential side wiring and the low-potential side wiring, and each leg consists of an upper arm switch (651u) connected to the high-potential side wiring and a lower arm switch (651d) connected to the low-potential side wiring connected in series. The hydrogen production system according to [1], wherein the connection point between the upper arm switch and the lower arm switch in the leg is connected to the input wiring (601) into which the three-phase AC power is input. [3] The hydrogen production system according to [1] or [2], comprising a plurality of electrolytic devices, each of which is connected in parallel to the plurality of power converters, and the control device is configured to correct at least one of the voltages or currents of the plurality of power converters so that the total amount of hydrogen produced by the plurality of electrolytic devices reaches a predetermined target amount. [4] The control device is configured to correct at least one of the voltages and currents of the multiple power converters so that when the operation of some of the multiple electrolytic devices stops, the total amount of hydrogen produced by the other electrolytic devices that continue to operate reaches a predetermined target amount, as described in [3]. [5] The control device is configured such that, when hydrogen production by some of the electrolytic devices stops, it connects the power converter that was connected to the electrolytic device to one of the other electrolytic devices, and corrects at least one of the voltages and currents of the multiple power converters so that the total amount of hydrogen produced by the electrolytic devices that continue to produce hydrogen reaches a predetermined target amount, as described in [3] or [4]. [6] The control device is configured to stop supplying power from some of the power converters to the electrolytic device when an abnormality is detected in some of the power converters among the plurality of power converters, according to any one of [1] to [5]. [7] The control device is configured to stop supplying power from the power converter to the electrolytic device when replacing some of the power converters among the plurality of power converters, according to any one of [1] to [6]. [8] The hydrogen production system according to any one of [1] to [7], wherein the control device sets at least one of the voltage and current of the power converters that continue to supply power to the electrolytic device to the electrolytic device while the power supply from some of the power converters to the electrolytic device is stopped. [9] A hydrogen production system (1) comprising an electrolytic device (2, 21, 22, 23) that electrolyzes raw materials to produce hydrogen, and a plurality of power converters (3, 31, 32, 33, 34, 35, 36, 37, 38, 39) that convert three-phase AC power into DC power and supply the DC power to the electrolytic device, wherein the electrolytic device is connected to a plurality of the power converters connected in parallel with each other, a method for producing hydrogen by a hydrogen production system (1), A hydrogen production method comprising, when the power supply to the electrolytic device from some of the power converters among the plurality of power converters is stopped, correcting at least one of the voltage and current of the power converters that continue to supply power to the electrolytic device so that the amount of hydrogen produced by the electrolytic device thereafter reaches a predetermined target amount, and setting the corrected value to the corrected value.

[10] The power converter includes a first power converter (3A) that converts the three-phase AC power into DC power, and a second power converter (3B) that converts the DC power converted by the first power converter into DC power of a different voltage, and the first power converter and the second power converter are connected by a high-potential side wiring (63H) and a low-potential side wiring (63L). The first power conversion unit has three or more legs (641) connected in parallel to each other between the high-potential side wiring and the low-potential side wiring, and each leg consists of an upper arm switch (651u) connected to the high-potential side wiring and a lower arm switch (651d) connected to the low-potential side wiring connected in series. The hydrogen production method according to [9], wherein the connection point between the upper arm switch and the lower arm switch in the leg is connected to the input wiring (601) into which the three-phase AC power is input.

[11] The hydrogen production system comprises a plurality of electrolytic devices, each of the plurality of electrolytic devices is connected to a plurality of power converters connected in parallel with each other, and at least one of the voltages or currents of the plurality of power converters is corrected so that the total amount of hydrogen produced by the plurality of electrolytic devices is a predetermined target amount, the hydrogen production method according to claim [9] or

[10] .

[12] The hydrogen production method according to

[11] , wherein if the operation of some of the electrolytic devices among the plurality of electrolytic devices is stopped, at least one of the voltages and currents of the plurality of power converters is corrected so that the total amount of hydrogen produced by the other electrolytic devices that continue to operate reaches a predetermined target amount.

[13] The hydrogen production method according to

[11] , wherein when hydrogen production by some of the electrolytic devices among the plurality of electrolytic devices stops, the power converter that was connected to the electrolytic device is connected to one of the other electrolytic devices, and at least one of the voltages and currents of the plurality of power converters is corrected so that the total amount of hydrogen produced by the electrolytic devices that continue to produce hydrogen reaches a predetermined target amount.

[14] A hydrogen production method according to any one of [9] to

[13] , wherein when an abnormality is detected in some of the power converters among the plurality of power converters, the power supply from the power converter to the electrolytic device is stopped.

[15] A hydrogen production method according to any one of [9] to

[14] , wherein when some of the power converters among the plurality of power converters are replaced, the power supply from the power converters to the electrolytic device is stopped.

[16] A hydrogen production method according to any one of [9] to

[14] , wherein, while the power supply from some of the power converters to the electrolytic device is stopped, at least one of the voltage and current of the power converter that continues to supply power to the electrolytic device is set to the corrected value.

[17] A program for controlling the control device of a hydrogen production system comprising an electrolytic apparatus (2, 21, 22, 23) that electrolyzes raw materials to produce hydrogen, a plurality of power converters (3, 31, 32, 33, 34, 35, 36, 37, 38, 39) that convert three-phase AC power into DC power and supply the DC power to the electrolytic apparatus, and a control device (4) that controls the power converters, wherein the electrolytic apparatus is connected to a plurality of the power converters connected in parallel with each other. A program that causes the control device to correct at least one of the voltage and current of the power converters that continue to supply power to the electrolytic device, so that the amount of hydrogen produced by the electrolytic device thereafter reaches a predetermined target amount, when the power supply from some of the power converters among the plurality of power converters to the electrolytic device is stopped. [Explanation of Symbols]

[0099] 1. Hydrogen production system 2, 21, 22, 23 Electrolyzer 3, 31, 32, 33, 34, 35, 36, 37, 38, 39 Power converter 4. Control device

Claims

1. Electrolytic devices (2, 21, 22, 23) that generate hydrogen by electrolyzing raw materials, Multiple power converters (3, 31, 32, 33, 34, 35, 36, 37, 38, 39) convert three-phase AC power into DC power and supply the DC power to the electrolytic device, The system includes a control device (4) for controlling the power converter, Multiple power converters are connected to the electrolytic device in parallel with each other. Hydrogen production system (1), wherein the control device is configured to correct at least one of the voltage and current of the power converters that continue to supply power to the electrolytic device, so that when the power supply from some of the power converters among the plurality of power converters to the electrolytic device is stopped, the amount of hydrogen produced by the electrolytic device thereafter reaches a predetermined target amount.

2. The power conversion device includes a first power conversion unit (3A) that converts the three-phase AC power into DC power, and a second power conversion unit (3B) that converts the DC power converted by the first power conversion unit into DC power of a different voltage, and the first power conversion unit and the second power conversion unit are connected by a high-potential side wiring (63H) and a low-potential side wiring (63L). The first power conversion unit has three or more legs (641) connected in parallel to each other between the high-potential side wiring and the low-potential side wiring, and each leg is made up of an upper arm switch (651u) connected to the high-potential side wiring and a lower arm switch (651d) connected to the low-potential side wiring connected in series. The hydrogen production system according to claim 1, wherein the connection point between the upper arm switch and the lower arm switch in the leg is connected to the input wiring (601) into which the three-phase AC power is input.

3. The hydrogen production system according to claim 1 or 2, comprising a plurality of electrolytic devices, each of which is connected in parallel to the plurality of power converters, and the control device is configured to correct at least one of the voltages or currents of the plurality of power converters so that the total amount of hydrogen produced by the plurality of electrolytic devices reaches a predetermined target amount.

4. The hydrogen production system according to claim 3, wherein the control device is configured to correct at least one of the voltages and currents of the multiple power converters so that when the operation of some of the multiple electrolytic devices stops, the total amount of hydrogen produced by the other electrolytic devices that continue to operate reaches a predetermined target amount.

5. The hydrogen production system according to claim 3, wherein the control device is configured to, when hydrogen production by some of the electrolytic devices among the plurality of electrolytic devices stops, connect the power converter that was connected to the electrolytic device to one of the other electrolytic devices, and correct at least one of the voltages and currents of the plurality of power converters so that the total amount of hydrogen produced by the electrolytic devices that continue to produce hydrogen reaches a predetermined target amount.

6. The hydrogen production system according to claim 1 or 2, wherein the control device is configured to stop supplying power from some of the power converters to the electrolytic device when an abnormality is detected in some of the power converters among the plurality of power converters.

7. The hydrogen production system according to claim 1 or 2, wherein the control device is configured to stop supplying power from the power converter to the electrolytic device when replacing some of the power converters among the plurality of power converters.

8. The hydrogen production system according to claim 1 or 2, wherein the control device sets at least one of the voltage and current of the power converters that continue to supply power to the electrolytic device to the electrolytic device to the corrected value while the power supply from some of the power converters to the electrolytic device is stopped.

9. A method for producing hydrogen using a hydrogen production system (1), comprising an electrolytic device (2, 21, 22, 23) that generates hydrogen by electrolyzing a raw material, and a plurality of power converters (3, 31, 32, 33, 34, 35, 36, 37, 38, 39) that convert three-phase AC power into DC power and supply the DC power to the electrolytic device, wherein the electrolytic device is connected to a plurality of the power converters connected in parallel with each other, A hydrogen production method comprising, when the power supply to the electrolytic device from some of the power converters among the plurality of power converters is stopped, correcting at least one of the voltage and current of the power converters that continue to supply power to the electrolytic device so that the amount of hydrogen produced by the electrolytic device thereafter reaches a predetermined target amount, and setting the corrected value to the corrected value.

10. The power conversion device includes a first power conversion unit (3A) that converts the three-phase AC power into DC power, and a second power conversion unit (3B) that converts the DC power converted by the first power conversion unit into DC power of a different voltage, and the first power conversion unit and the second power conversion unit are connected by a high-potential side wiring (63H) and a low-potential side wiring (63L). The first power conversion unit has three or more legs (641) connected in parallel to each other between the high-potential side wiring and the low-potential side wiring, and each leg is made up of an upper arm switch (651u) connected to the high-potential side wiring and a lower arm switch (651d) connected to the low-potential side wiring connected in series. The hydrogen production method according to claim 9, wherein the connection point between the upper arm switch and the lower arm switch in the leg is connected to the input wiring (601) into which the three-phase AC power is input.

11. The hydrogen production system comprises a plurality of electrolytic devices, each of which is connected in parallel to the plurality of power converters, and the method for producing hydrogen according to claim 9 or 10, wherein at least one of the voltages or currents of the plurality of power converters is corrected so that the total amount of hydrogen produced by the plurality of electrolytic devices reaches a predetermined target amount.

12. The hydrogen production method according to claim 11, wherein, when the operation of some of the electrolytic devices among the plurality of electrolytic devices is stopped, at least one of the voltages and currents of the plurality of power converters is corrected so that the total amount of hydrogen produced by the other electrolytic devices that continue to operate reaches a predetermined target amount.

13. The hydrogen production method according to claim 11, wherein, when hydrogen production by some of the electrolytic devices among the plurality of electrolytic devices stops, the power converter that was connected to the electrolytic device is connected to one of the other electrolytic devices, and at least one of the voltages and currents of the plurality of power converters is corrected so that the total amount of hydrogen produced by the electrolytic devices that continue to produce hydrogen reaches a predetermined target amount.

14. The hydrogen production method according to claim 9 or 10, wherein when an abnormality is detected in some of the power converters among the plurality of power converters, the power supply from the power converter to the electrolytic device is stopped.

15. The hydrogen production method according to claim 9 or 10, wherein when some of the power converters among the plurality of power converters are replaced, the power supply from the power converters to the electrolytic device is stopped.

16. The hydrogen production method according to claim 9 or 10, wherein, while the power supply from some of the power converters to the electrolytic device is stopped, at least one of the voltage and current of the power converters that continue to supply power to the electrolytic device is set to the corrected value.

17. A program for controlling the control device of a hydrogen production system comprising: an electrolytic apparatus (2, 21, 22, 23) that electrolyzes raw materials to produce hydrogen; a plurality of power converters (3, 31, 32, 33, 34, 35, 36, 37, 38, 39) that convert three-phase AC power into DC power and supply the DC power to the electrolytic apparatus; and a control device (4) that controls the power converters, wherein the electrolytic apparatus is connected to a plurality of the power converters connected in parallel to each other. A program that causes the control device to correct at least one of the voltage and current of the power converters that continue to supply power to the electrolytic device, so that the amount of hydrogen produced by the electrolytic device thereafter reaches a predetermined target amount, when the power supply from some of the power converters among the plurality of power converters to the electrolytic device is stopped.

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