System and method for driving railroad vehicle

Abstract

To enable a railroad vehicle loaded with a fuel battery to efficiently store hydrogen generated by electrolyzing water to reuse the hydrogen for enabling the fuel battery to generate power.SOLUTION: A system for driving a railroad vehicle, which drives a railroad vehicle using a fuel battery as a power source, is provided with: a high-pressure hydrogen storage device that stores hydrogen filled at high pressure; a fuel battery that generates power using hydrogen as fuel; a water storage device that stores water generated when the fuel battery generates power; an electrolyzing device that electrolyzes water stored in the water storage device, using surplus power; and an auxiliary hydrogen storage device that stores hydrogen generated by electrolyzing water, at pressure lower than pressure for storing hydrogen in the high-pressure hydrogen storage device, where hydrogen stored in the auxiliary hydrogen storage device is reused for the fuel battery to generate power.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technique for driving a railway vehicle (hereinafter also simply referred to as a "vehicle"). [Background technology]

[0002] In recent years, the reduction of the burden on the global environment has become an urgent issue for the entire industrial world, and in the rail transport industry, the practical application of rail vehicles equipped with fuel cells as a new power source to replace internal combustion engines such as diesel engines that use light oil as fuel is being promoted. Fuel cells are a type of battery that generates electricity by supplying fuel such as hydrogen together with an oxidizer from the outside, and since they can significantly reduce the environmental burden compared to internal combustion engines that use fossil fuels, they are also highly anticipated as a power source for rail vehicles.

[0003] In relation to these efforts to install fuel cells as a power source in railway vehicles, for example, JP2019-527012A (hereinafter referred to as "Patent Document 1") states that "when the braking energy recycling system is applied to hybrid railway transportation, based on the characteristic that hybrid railway transportation vehicles have hydrogen gas tanks, only an electrolytic cell is added to the structure, and the existing on-board hydrogen gas tank is used as is to store hydrogen, resulting in a simple structure, reduced vehicle weight, high energy conversion efficiency, and at the same time reduced need for hydrogen gas refueling, thereby reducing operating costs" (see paragraph

[0013] ).

[0004] Furthermore, in relation to a general fuel cell that uses hydrogen as fuel, for example, International Publication No. 2018 / 096713 (hereinafter referred to as "Patent Document 2") describes that "the hydrogen storage tank and the oxygen storage tank store hydrogen or oxygen at a high pressure of, for example, 1 to 30 MPa, respectively" (see paragraph

[0039] ), and that "When pressurizing hydrogen generated in the water electrolysis device, the switching valve is closed while the water electrolysis device is generating and discharging hydrogen. In this state, the hydrogen is gradually pressurized in the piping upstream of the switching valve. Therefore, by measuring the hydrogen pressure using a separate sensor or the like and opening the switching valve when the hydrogen pressure becomes higher than the pressure in the hydrogen storage tank, the hydrogen generated in the water electrolysis device can be suitably introduced into the hydrogen storage tank" (see paragraph

[0040] ). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2019-527012 [Patent Document 2] International Publication No. 2018 / 096713 Summary of the Invention [Problem to be solved by the invention]

[0006] As part of an effort to install fuel cells on railway vehicles, the inventors conducted extensive research into a railway vehicle drive system equipped with a fuel cell that generates electricity from hydrogen fuel, a hydrogen storage device, and a water electrolysis device, and as a result, arrived at the following insight.

[0007] First, in the technology described in Patent Document 1, hydrogen gas generated by electrolysis is stored as is in an existing hydrogen gas tank on board the vehicle. The pressure in this existing hydrogen gas tank is usually higher than atmospheric pressure because a sufficient amount of hydrogen gas is usually stored in the hydrogen gas tank in a compressed state. Therefore, the technology described in Patent Document 1 has a problem in that hydrogen generated by electrolysis of water at atmospheric pressure cannot be stored in the hydrogen gas tank as is without being compressed.

[0008] Secondly, in the technology described in Patent Document 2, hydrogen is introduced into a hydrogen storage tank that stores hydrogen at a high pressure of 1 to 30 MPa by appropriately opening and closing a switching valve provided in a hydrogen piping system. However, the pressure inside a hydrogen storage tank mounted on a railway vehicle is almost always higher than 30 MPa because the volume of the hydrogen storage tank is usually relatively small compared to that of a land-based tank. Therefore, the switching valve described in Patent Document 2 has a problem in that it is difficult to pressurize hydrogen to a sufficient pressure and send it into the hydrogen storage tank mounted on the railway vehicle.

[0009] On the other hand, for example, if a compressor is used to increase the pressure of hydrogen above that inside the hydrogen storage tank, the compressor may become too large to install on a railway vehicle, and the amount of power consumed during compression may be so large that it may actually worsen the energy efficiency inside the railway vehicle.

[0010] An object of the present invention is to efficiently store hydrogen produced by electrolysis of water in a rail vehicle equipped with a fuel cell and reuse it for power generation in the fuel cell. [Means for solving the problem]

[0011] The present invention relates to a railway vehicle drive system that drives railway vehicles using a fuel cell as a power source, and includes a high-pressure hydrogen storage device that stores hydrogen filled at high pressure, a fuel cell that generates electricity using hydrogen as fuel, a water storage device that stores water produced when the fuel cell generates electricity, an electrolysis device that electrolyzes the water stored in the water storage device using surplus electricity, and an auxiliary hydrogen storage device that stores the hydrogen produced by the electrolysis of water at a pressure lower than the hydrogen storage pressure of the high-pressure hydrogen storage device, and the hydrogen stored in the auxiliary hydrogen storage device is used to generate electricity for the fuel cell. Effect of the Invention

[0012] According to the present invention, in a railcar equipped with a fuel cell, hydrogen produced by electrolysis of water can be efficiently stored and reused for power generation by the fuel cell. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating an example of a configuration of a railway vehicle drive system according to a first embodiment. [Diagram 2] FIG. 4 is a diagram illustrating an example of another configuration of the railway vehicle drive system according to the first embodiment. [Diagram 3] 4 is a time chart showing an example of the operation of the railway vehicle drive system according to the first embodiment. [Figure 4A] FIG. 2 is a diagram showing a schematic example of an energy flow in a powered train; [Figure 4B] FIG. 2 is a diagram showing a schematic example of energy flow in a train during regeneration. [Figure 4C] FIG. 2 is a diagram showing a schematic example of energy flow in a train during regeneration. [Diagram 5] 4 is a flowchart illustrating an example of the relationship between the operating state of a train and the state of a fuel cell. [Figure 6] 4 is a flowchart illustrating an example of the relationship between the operating state of a train and the state of an electrolyzer. [Figure 7] FIG. 11 is a diagram illustrating an example of a configuration of a railway vehicle drive system according to a second embodiment. [Figure 8] 10 is a time chart showing an example of the operation of the railway vehicle drive system according to the second embodiment. [Figure 9] FIG. 11 is a diagram illustrating an example of a configuration of a railway vehicle drive system according to a third embodiment. [Figure 10] 11 is a time chart showing an example of the operation of the railway vehicle drive system according to the third embodiment. [Figure 11] FIG. 11 is a diagram illustrating an example of the configuration of a railway vehicle drive system according to a fourth embodiment. [Figure 12] 13 is a time chart showing an example of the operation of the railway vehicle drive system according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Various embodiments of the present invention will now be described in detail with reference to the drawings.

[0015] In the following description, the same or similar components will be denoted by common reference symbols to avoid repetitive description.

[0016] In addition, when there are multiple elements having the same or similar functions, the multiple elements may be described by using the same reference numerals with different subscripts in order to distinguish between them. On the other hand, when there is no need to distinguish between the multiple elements, the subscripts may be omitted. EXAMPLES

[0017] (Configuration example of railway vehicle drive system 100a) First, a configuration example of a railway vehicle traction system 100a according to a first embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram that illustrates a schematic configuration example of the railway vehicle traction system 100a.

[0018] The railway vehicle traction system 100a is a system that mainly supplies power to various devices mounted on a railway vehicle (not shown) and controls the drive of a power motor 1 for driving the railway vehicle.

[0019] Specific examples of devices to which the railway vehicle drive system 100a supplies power include various devices constituting the railway vehicle drive system 100a, and auxiliary machinery of the railway vehicle, such as air conditioners, lighting, and the like.

[0020] 1, the railway vehicle drive system 100a according to the first embodiment includes at least the above-mentioned power motor 1, a power inverter 2, a fuel cell 5, an electrolyzer 6, a high-pressure hydrogen storage device 7, an auxiliary hydrogen storage device 8, a water storage device 9, a first valve or high-pressure hydrogen storage device valve 10a, a second valve or auxiliary hydrogen storage device valve 10b, a fuel cell open switch 11, an electrolyzer open switch 12, and a controller 19. In addition to these components, the railway vehicle drive system 100a may also include an auxiliary power supply unit 3, a filter capacitor (4a, 4b), an external water supply means 14, a compressor 13, etc.

[0021] The power inverter 2 is an indispensable reverse conversion device for controlling the drive of the power motor 1. When the train associated with the railcar is powered, the power inverter 2 converts DC power supplied from the fuel cell 5 via filter capacitors (4a, 4b) into three-phase AC power using an inverter circuit and supplies the power to the power motor 1. When the train is braking, the power inverter 2 can also convert the three-phase AC power regenerated by the power motor 1 into DC power and supply it to the DC section of the main circuit (not shown) of the railcar.

[0022] The auxiliary power supply 3 converts the power supplied from the DC part of the main circuit into low-voltage AC or DC, and supplies the power to the auxiliary equipment of the railway vehicle, such as air conditioning and lighting.

[0023] Since the railway vehicle traction system 100a according to the first embodiment and the railway vehicle traction system 100b according to a second embodiment described later run mainly on non-electrified sections of the line on which the trains run, they do not include components related to a current collector, as illustrated in Fig. 1 and Figs. 2 and 7 described later. Therefore, surplus regenerative power generated during braking of the train by regenerative braking (hereinafter also referred to as "during regeneration") is not returned to the overhead lines, but is converted to DC power by the power inverter 2 and supplied to the DC section of the main circuit of the railway vehicle.

[0024] The number of drive motors 1 connected to the drive inverter 2 may be one or more.

[0025] The fuel cell 5 is an energy conversion device that generates electricity by chemically reacting hydrogen gas (hereinafter also referred to as "hydrogen fuel"), which is supplied as fuel, with oxygen in the air. That is, the fuel cell 5 generates electricity from hydrogen fuel (hereinafter also simply referred to as "hydrogen"). The generated electricity is supplied as DC power to the power inverter 2 and the DC section of the main circuit of the railway vehicle. The fuel cell 5 and the DC section of the main circuit of the railway vehicle are electrically connected or disconnected by switching between the opening and closing operations of a fuel cell open switch 11.

[0026] Furthermore, water is produced during power generation in the fuel cell 5. The produced water is stored in a water storage device 9, which will be described later.

[0027] The high-pressure hydrogen storage device 7 is a device that stores hydrogen filled at a pressure higher than 30 MPa. The hydrogen stored in this high-pressure hydrogen storage device 7 is filled in advance, for example, at the starting station of the train, and is supplied as fuel to the fuel cell 5. Between the high-pressure hydrogen storage device 7 and the fuel cell 5, a high-pressure hydrogen storage device valve 10a is provided for controlling the open / closed state and the amount of hydrogen that flows out.

[0028] The water storage device 9 is a device that stores water generated when the fuel cell 5 generates electricity. The water stored in the water storage device 9 is supplied to the electrolyzer 6. The water storage device 9 may be provided with an external water supply means 14 in addition to the water discharged from the fuel cell 5.

[0029] The electrolyzer 6 is a device that electrolyzes water stored in the water storage device 9 to generate hydrogen and oxygen. The DC power used in electrolyzing water in the electrolyzer 6 is surplus power supplied from the DC section of the main circuit of the railway vehicle. This surplus power is mainly surplus regenerative power generated during regeneration of the train, which is converted into DC power by the power inverter 2 and supplied to the DC section of the main circuit of the railway vehicle.

[0030] The electrolyzer 6 and the DC section of the main circuit of the railway vehicle are electrically connected or disconnected by switching the opening and closing operation of an electrolyzer open switch 12. This electrolyzer open switch 12 is controlled to electrically disconnect the electrolyzer 6 and the DC section of the main circuit of the railway vehicle while the train is powering, and to electrically connect the electrolyzer 6 and the DC section of the main circuit of the railway vehicle while the train is regenerating. As a result, during regeneration of the train, surplus regenerative power once supplied to the DC section of the main circuit of the railway vehicle is supplied to the electrolyzer 6, and the electrolyzer 6 can electrolyze water to generate hydrogen and oxygen.

[0031] That is, the railway vehicle traction system 100a can generate hydrogen using surplus regenerative power generated during regeneration of the train and water produced during power generation in the fuel cell 5, and supply the hydrogen to the fuel cell 5.

[0032] The auxiliary hydrogen storage device 8 is a device that stores hydrogen produced by electrolyzing water with the electrolyzer 6. The hydrogen produced by electrolyzing water is stored inside the auxiliary hydrogen storage device 8 at a pressure lower than the internal pressure of the high-pressure hydrogen storage device 7, for example, a pressure of just over 1 MPa, which is close to atmospheric pressure. The hydrogen stored in the auxiliary hydrogen storage device 8 is supplied to the fuel cell 5 as fuel. In other words, the hydrogen stored in the auxiliary hydrogen storage device 8 is supplied to the fuel cell 5 and used for power generation. An auxiliary hydrogen storage device valve 10b is provided between the auxiliary hydrogen storage device 8 and the fuel cell 5 to control the open / closed state and the amount of hydrogen that flows out.

[0033] As described above, the railway vehicle traction system 100a may include a compressor 13. When the compressor 13 is provided between the electrolyzer 6 and the auxiliary hydrogen storage device 8 in the railway vehicle traction system 100a as illustrated in Fig. 1, the hydrogen generated in the electrolyzer 6 is discharged from the compressor 13 at a pressure slightly higher than atmospheric pressure, so that it can be reliably sent into the auxiliary hydrogen storage device 8.

[0034] Furthermore, since it is sufficient for this compressor 13 to be able to discharge hydrogen at a pressure slightly higher than atmospheric pressure, for example just over 1 MPa, its external dimensions and weight can be made small enough to be mounted on the railway vehicle.

[0035] The controller 19 is a control device for performing various controls in the railway vehicle drive system 100a. The controller 19 is connected to the power motor 1, power inverter 2, auxiliary power supply unit 3, fuel cell 5, electrolyzer 6, high-pressure hydrogen storage device valve 10a, auxiliary hydrogen storage device valve 10b, fuel cell open switch 11, electrolyzer open switch 12, compressor 13, etc., so as to issue operation commands to these components. The controller 19 includes at least a storage device and a processor connected to the storage device, and is realized by an on-board computer device and / or a control board mounted on the railway vehicle.

[0036] The storage device included in the controller 19 may be at least one of a memory and a persistent storage device. The memory may be one or more memory devices, which are an example of one or more storage devices, and may typically be a primary storage device. At least one of the memory devices in the memory may be a volatile memory device or a non-volatile memory device.

[0037] The controller 19 may also include a persistent storage device as a storage device. The persistent storage device may be one or more persistent storage devices, which are an example of one or more storage devices. The persistent storage device may typically be a non-volatile storage device (e.g., an auxiliary storage device), and specifically may be, for example, a hard disk drive (HDD), a solid state drive (SSD), a non-volatile memory express (NVME) drive, or a storage class memory (SCM).

[0038] The processor included in the controller 19 may be one or more processor devices. The controller 19 may be configured to include a microcontroller (Micro Controller Unit; MCU) including one or more processor devices. The at least one processor device may typically be a microprocessor device such as a CPU (Central Processing Unit), but may also be another type of processor device such as a GPU (Graphics Processing Unit). The at least one processor device may be a single-core or multi-core. The at least one processor device may be a processor core. The at least one processor device may also be a broad processor device such as a circuit that is a collection of gate arrays using a hardware description language that performs part or all of the processing (for example, an FPGA (Field-Programmable Gate Array), a CPLD (Complex Programmable Logic Device), or an ASIC (Application Specific Integrated Circuit)).

[0039] The controller 19 issues operation commands to the high-pressure hydrogen storage device valve 10a and / or the auxiliary hydrogen storage device valve 10b in accordance with the internal pressure of the auxiliary hydrogen storage device 8 obtained from, for example, a pressure sensor (not shown) provided inside the auxiliary hydrogen storage device 8. In this case, the controller 19 generates an open command signal for commanding the high-pressure hydrogen storage device valve 10a or the auxiliary hydrogen storage device valve 10b to open or a close command signal for commanding a close operation, and transmits these signals to the high-pressure hydrogen storage device valve 10a or the auxiliary hydrogen storage device valve 10b. The controller 19 also issues operation commands to the fuel cell open switch 11, the electrolyzer open switch 12, the compressor 13, etc. by transmitting the various signals it has generated in a similar manner.

[0040] In addition to the above-mentioned components, the railway vehicle traction system 100a may further include other components. For example, the railway vehicle traction system 100a may include a current control device 20 as shown in Fig. 2. The current control device 20 is a device that controls each current so that each current becomes a target voltage.

[0041] (Operation example of railway vehicle drive system 100a) Next, an example of the operation of the railway vehicle traction system 100a according to the first embodiment will be described with reference to the graphs shown in Fig. 3. Fig. 3 is a time chart showing an example of the operation of the railway vehicle traction system 100a.

[0042] The graphs in Figure 3, from top to bottom, represent the following 13 items: (a) The operating status of the train to which the rail vehicle relates (b) Example of change in power supply to power inverter 2 over time (c) Example of change over time in power consumption of auxiliary power supply 3 (d) Example of time change in the total power of the power inverter 2 and the auxiliary power supply 3 (e) State of fuel cell open switch 11 (f) Operating state of fuel cell 5 (g) Example of change in internal pressure of auxiliary hydrogen storage device 8 over time (h) Example of change in hydrogen supply source over time (i) Operation state of auxiliary hydrogen storage device valve 10b (j) Operation state of the high-pressure hydrogen storage device valve 10a (k) Operational status of electrolyzer 6 (l) State of electrolysis device opening switch 12 (m) Operation status of compressor 13

[0043] Moreover, each graph in FIG. 3 shows an example of how the above items change over time when the train related to the railway vehicle runs mainly on non-electrified sections.

[0044] At time t1, the controller 19 sends a close command signal to the fuel cell open switch 11, which is in the open state, causing the fuel cell open switch 11 to close and supply DC power to the main circuit from the fuel cell 5. Also, at time t1, when the stopped auxiliary power supply 3 is switched to an energized state, power is consumed in the auxiliary power supply 3.

[0045] In the railcar drive system 100a, when the fuel cell 5 generates power, the hydrogen stored in the auxiliary hydrogen storage device 8 is supplied to the fuel cell 5 with priority over the hydrogen stored in the high-pressure hydrogen storage device 7. This is because, as described above, the hydrogen stored in the high-pressure hydrogen storage device 7 is filled with hydrogen at a high pressure in advance at the starting station of the train related to the railcar, and cannot be replenished while the train is running, whereas the hydrogen stored in the auxiliary hydrogen storage device 8 can be replenished by operating the electrolysis device 6 while the train is running to generate new hydrogen. In addition, by using the hydrogen stored in the auxiliary hydrogen storage device 8 with priority, the internal pressure of the auxiliary hydrogen storage device 8 can be lowered, and the amount of power consumed by the compressor 13 required to store hydrogen generated during the next electrolysis can be reduced. Therefore, the controller 19 of the railcar drive system 100a controls the opening and closing operations of the high-pressure hydrogen storage device valve 10a and the auxiliary hydrogen storage device valve 10b so that the hydrogen stored in the auxiliary hydrogen storage device 8 is preferentially sent to the fuel cell 5 when the fuel cell 5 generates power. Because the hydrogen supply source to the fuel cell 5 at time t1 is the auxiliary hydrogen storage device 8, the controller 19 of the railway vehicle drive system 100a sends an open command signal to the auxiliary hydrogen storage device valve 10b, which is in the closed state. This causes the auxiliary hydrogen storage device valve 10b to open, hydrogen is supplied to the fuel cell 5, and power generation begins. As a result, the internal pressure of the auxiliary hydrogen storage device 8 decreases in accordance with the amount of hydrogen supplied to the fuel cell 5.

[0046] At time t2, when the train starts powering, the power consumption of the power inverter 2, which was zero, increases, and this increase is reflected in the total power of the power inverter 2 and the auxiliary power supply 3.

[0047] At time t3, when the internal pressure of the auxiliary hydrogen storage device 8 reaches a predetermined lower threshold, the controller 19 of the railway vehicle drive system 100a sends an open command signal to the closed high-pressure hydrogen storage device valve 10a and sends a close command signal to the open auxiliary hydrogen storage device valve 10b, in order to switch the hydrogen supply source to the fuel cell 5 from the auxiliary hydrogen storage device 8 to the high-pressure hydrogen storage device 7. As a result, the high-pressure hydrogen storage device valve 10a becomes open and the auxiliary hydrogen storage device valve 10b becomes closed, and the hydrogen supply source to the fuel cell 5 is switched from the auxiliary hydrogen storage device 8 to the high-pressure hydrogen storage device 7.

[0048] At time t4, when the train stops powering and transitions to a coasting state, the power consumption of the power inverter 2 decreases and becomes zero again, and this decrease is reflected in the total power of the power inverter 2 and the auxiliary power supply 3.

[0049] At time t5, when the traction motor 1 of the railway vehicle starts regeneration, the generated power of the traction inverter 2, which was 0, increases, and this change is reflected in the total power of the traction inverter 2 and the auxiliary power supply 3.

[0050] Furthermore, at time t5, the controller 19 of the railway vehicle drive system 100a sends a close command signal to the open high-pressure hydrogen storage device valve 10a. This closes the high-pressure hydrogen storage device valve 10a in addition to the already closed auxiliary hydrogen storage device valve 10b, cutting off the hydrogen supply path to the fuel cell 5. As a result, the fuel cell 5 stops generating power.

[0051] Furthermore, at time t5, the controller 19 of the railway vehicle drive system 100a sends a close command signal to the open electrolyzer open switch 12, and also sends an operation start signal to the stopped compressor 13 to start its operation. As a result, the electrolyzer open switch 12 is closed and power is supplied to the electrolyzer 6, so that the stopped electrolyzer 6 starts electrolyzing the water stored in the water storage device 9. As a result, new hydrogen is produced. The hydrogen produced by the electrolyzer 6 is sent by the compressor 13 to the inside of the auxiliary hydrogen storage device 8, and the internal pressure of the auxiliary hydrogen storage device 8, which had reached the lower limit threshold, rises again.

[0052] The power generated by the power inverter 2 decreases in accordance with the decrease in the train speed during regeneration of the train. This change is reflected in the total power of the power inverter 2 and the auxiliary power supply 3, and the total power becomes 0 at time t6 and then starts to be consumed.

[0053] Furthermore, at time t6, the controller 19 of the railway vehicle drive system 100a sends an open command signal to the closed electrolyzer open switch 12, and also sends an operation stop signal to the operating compressor 13 to stop its operation. This causes the electrolyzer open switch 12 to enter an open state, cutting off the supply of power to the electrolyzer 6, and causes the operating electrolyzer 6 to stop operating. As a result, new hydrogen is no longer produced in the electrolyzer 6, and the supply of hydrogen to the auxiliary hydrogen storage device 8 stops.

[0054] Furthermore, at time t6, because the internal pressure of the auxiliary hydrogen storage device 8 is sufficiently high, the controller 19 of the railway vehicle drive system 100a sends an open command signal to the closed auxiliary hydrogen storage device valve 10b. This opens the auxiliary hydrogen storage device valve 10b, hydrogen is supplied to the fuel cell 5, and power generation is restarted. As a result, the internal pressure of the auxiliary hydrogen storage device 8, which had been rising, decreases in accordance with the amount of hydrogen supplied to the fuel cell 5, and begins to decrease again.

[0055] At time t7, the traction motor 1 of the railway vehicle stops regeneration, and the regenerative power of the traction inverter 2, which had been decreasing, becomes 0. This decrease is reflected in the total power of the traction inverter 2 and the auxiliary power supply 3, and this total power becomes the same as the power consumption of the auxiliary power supply 3.

[0056] At time t8, the controller 19 of the railway vehicle traction system 100a transmits a stop signal to the energized auxiliary power supply 3. This causes the auxiliary power supply 3 to stop, and the power consumption of the traction inverter 2 and the auxiliary power supply 3 becomes zero.

[0057] Also, at time t8, the controller 19 of the railway vehicle drive system 100a sends a close command signal to the open auxiliary hydrogen storage device valve 10b. This closes the auxiliary hydrogen storage device valve 10b, blocking the hydrogen supply path to the fuel cell 5 and causing the operating fuel cell 5 to stop generating power. The controller 19 sends an open command signal to the closed fuel cell open switch 11, causing the fuel cell open switch 11 to open.

[0058] (Relationship between train running state and energy flow in railway vehicle drive system 100a) Next, the relationship between the running state of the train and the energy flow in the railcar traction system 100a will be described with reference to Fig. 4A to Fig. 4C. Fig. 4A is a diagram showing an example of the energy flow in the train during powering. Fig. 4B and Fig. 4C are diagrams showing an example of the energy flow in the train during regeneration.

[0059] As shown in FIG. 4A, while the train is powered, DC power generated by the fuel cell 5 is supplied to the power inverter 2 and the auxiliary power supply 3.

[0060] Also, as shown in FIG. 4B, when the train is in regeneration and the power consumed by the auxiliary power supply 3 is greater than the regenerative power of the power inverter 2, the regenerative power of the power inverter 2 is supplied to the auxiliary power supply 3 in addition to the DC power generated by the fuel cell 5.

[0061] 4C, when the train is in regeneration and the regenerative power of the power inverter 2 is equal to or greater than the power consumption of the auxiliary power supply 3, the regenerative power of the power inverter 2 is supplied to the electrolyzer 6 in addition to the auxiliary power supply 3. This surplus regenerative power can be used to electrolyze water in the electrolyzer 6, generating hydrogen together with oxygen.

[0062] (Relationship between train operation status and fuel cell 5 status) FIG. 5 is a flow chart illustrating an example of the relationship between the operating state of the train and the state of the fuel cell 5. In FIG.

[0063] As illustrated in FIG. 5, when the train is powering (step S501: YES), the state of the fuel cell 5 is generating electricity (step S503).

[0064] Furthermore, even if the train is not powering (step S501: NO), if the train is regenerating and the power consumption of the auxiliary power supply 3 is greater than the regenerated power (step S502: YES), the state of the fuel cell 5 will be generating power (step S503).

[0065] On the other hand, in other cases, i.e., when the train is not powering (step S501: NO) and the train is not regenerating power and / or the power consumption of the auxiliary power supply 3 is not greater than the regenerated power (step S502: NO), the state of the fuel cell 5 is not generating power but is stopped.

[0066] (Relationship between train operation status and electrolysis device 6 status) FIG. 6 is a flow chart illustrating an example of the relationship between the operating state of the train and the state of the electrolyzer 6.

[0067] 6, when the train is in regeneration and the regenerative power is greater than the power consumption of the auxiliary power supply 3 (step S601: YES), the state of the electrolyzer 6 becomes energized (step S602). As a result, electrolysis is performed in the electrolyzer 6, and hydrogen is produced together with oxygen.

[0068] On the other hand, in other cases, i.e., when the train is not regenerating and / or the regenerated power is not greater than the power consumption of the auxiliary power supply 3 (step S602: NO), the state of the electrolyzer 6 is not energized but stopped.

[0069] In this way, according to the railway vehicle drive system 100a, the hydrogen generated by supplying surplus regenerative power to the electrolysis device 6 can be stored inside the auxiliary hydrogen storage device 8 at a pressure lower than the internal pressure of the high-pressure hydrogen storage device 7, and can be used to generate electricity in the fuel cell 5.

[0070] Therefore, the energy consumption required for increasing the pressure to store the hydrogen produced by the electrolyzer 6 can be reduced.

[0071] Furthermore, in the railway vehicle drive system 100a, hydrogen stored inside the auxiliary hydrogen storage device 8 is supplied to the fuel cell 5 in preference to hydrogen filled at high pressure inside the high-pressure hydrogen storage device 7. This makes it possible to lower the internal pressure of the auxiliary hydrogen storage device 8, and enhances the effect of reducing the amount of energy consumed to store hydrogen generated by electrolysis. This also makes it possible to reduce the amount of hydrogen fuel used in a railway vehicle equipped with the fuel cell 5 as a drive source.

[0072] As a result, it will be possible to reduce the cost of hydrogen fuel, the time and frequency required for refueling with hydrogen fuel, and extend the range of trains related to the railway vehicles.

[0073] That is, according to the railway vehicle traction system 100a, surplus regenerative power can be converted into hydrogen by the electrolyzer 6, and the generated hydrogen can be efficiently stored in the auxiliary hydrogen storage device 8 and reused for power generation by the fuel cell 5.

[0074] The railway vehicle traction system 100a according to the first embodiment has been described above. EXAMPLES

[0075] Next, a description will be given of a railway vehicle traction system 100b according to Example 2. This railway vehicle traction system 100b is obtained by adding components related to a power storage device to the railway vehicle traction system 100a according to Example 1.

[0076] Therefore, the following description of the second embodiment will focus only on differences in functions, effects, etc. from the first embodiment, and descriptions of functions, effects, etc. common to the first embodiment will be omitted.

[0077] (Configuration example of railway vehicle drive system 100b) First, a configuration example of a railway vehicle traction system 100b according to the second embodiment will be described with reference to Fig. 7. Fig. 7 is a diagram that illustrates a schematic configuration example of the railway vehicle traction system 100b.

[0078] As described above, this railway vehicle drive system 100b is obtained by adding components related to the power storage device, specifically, the power storage device 15 and the power storage device opening switch 16 to the railway vehicle drive system 100a according to the first embodiment.

[0079] That is, the railway vehicle traction system 100b includes, in addition to the components included in the railway vehicle traction system 100a illustrated in FIG. 1, a power storage device 15 and a power storage device opening switch 16 as illustrated in FIG.

[0080] The power storage device 15 is a device that is connected to the DC part of the main circuit of the railway vehicle and performs charging and discharging. The power storage device 15 and the DC part of the main circuit of the railway vehicle are electrically connected or disconnected by switching the opening and closing operation of the power storage device opening switch 16.

[0081] The controller 19 issues an operation command to the power storage device opening switch 16 in accordance with the charging rate of the power storage device 15 acquired from the power storage device 15 .

[0082] When the storage device 15 becomes fully charged during regeneration of the train related to the railway vehicle, the storage device opening switch 16 is controlled by the controller 19 so as to electrically disconnect the storage device 15 from the DC section of the main circuit of the railway vehicle.

[0083] In this case, the electrolyzer opening switch 12 is controlled by the controller 19 so as to electrically connect the electrolyzer 6 to the DC portion of the main circuit of the railway vehicle.

[0084] (Operation example of railway vehicle drive system 100b) Next, an example of the operation of the railway vehicle traction system 100b according to the second embodiment will be described with reference to the graphs shown in Fig. 8. Fig. 8 is a time chart showing an example of the operation of the railway vehicle traction system 100b.

[0085] The graphs shown in Figure 8 represent the following 15 items, from top to bottom: (a) The operating status of the train to which the rail vehicle relates (b) Example of change in power supply to power inverter 2 over time (c) Example of change over time in power consumption of auxiliary power supply 3 (d) Example of time change in the total power of the power inverter 2 and the auxiliary power supply 3 (e) State of fuel cell open switch 11 (f) Operating state of fuel cell 5 (g) Example of time change in internal pressure of auxiliary hydrogen storage device 8 (h) Example of change in hydrogen supply source over time (i) Operation state of auxiliary hydrogen storage device valve 10b (j) Operation state of the high-pressure hydrogen storage device valve 10a (k) Operational status of electrolyzer 6 (l) State of electrolysis device opening switch 12 (m) Operation status of compressor 13 (n) Example of change over time in the charging rate of the power storage device 15 (o) State of the storage device opening switch 16

[0086] Of these, items (a) to (m) are the same as those in the first embodiment, and therefore the description thereof will be omitted.

[0087] Moreover, each graph in FIG. 8 shows an example of how the above items change over time when the train associated with the railway vehicle runs mainly on non-electrified sections.

[0088] At time t1, the controller 19 transmits a close command signal to the open power storage device open switch 16, which closes the power storage device open switch 16 and starts discharging the power storage device 15. As a result, the charge rate of the power storage device 15 decreases according to the amount of discharge, and reaches a lower limit threshold at time t3.

[0089] At time t6, when the power motor 1 of the railway vehicle starts regeneration, the surplus regenerated power is supplied to the power storage device 15, causing the power storage device 15 to start charging. As a result, the charging rate of the power storage device 15, which had reached the lower limit threshold, rises again in accordance with the amount of power supply, and reaches the upper limit threshold at time t7.

[0090] At time t7, when the charging rate of the power storage device 15 reaches the upper limit threshold, an open command signal is sent from the controller 19 to the closed power storage device opening switch 16. This causes the power storage device opening switch 16 to enter an open state, electrically disconnecting the power storage device 15 from the DC section of the main circuit of the railway vehicle, and the power storage device 15 stops charging.

[0091] At time t8, when a close command signal is sent from controller 19 to power storage device open switch 16, which is in the open state, power storage device open switch 16 is closed, and power storage device 15 starts discharging again. As a result, the charge rate of power storage device 15 decreases according to the amount of discharge. When the total power of power inverter 2 and auxiliary power supply device 3 becomes 0 at time t10, power storage device 15 stops discharging.

[0092] In this way, according to the railway vehicle drive system 100b, by charging the power storage device 15 with surplus regenerative power generated by the traction motor 1 of the railway vehicle, it is possible to improve the energy efficiency of the railway vehicle.

[0093] Furthermore, according to the railway vehicle drive system 100b, regenerative power that cannot be fully recovered by the power storage device 15 can be converted into hydrogen by the electrolysis device 6, and the hydrogen generated can be efficiently stored in the auxiliary hydrogen storage device 8 and reused for power generation in the fuel cell 5.

[0094] In other words, according to the railway vehicle drive system 100b, even when the power storage device 15 becomes fully charged due to a continuous downhill gradient or the like, the hydrogen generated by supplying the surplus regenerative power that the power storage device 15 was unable to recover to the electrolysis device 6 can be efficiently stored inside the auxiliary hydrogen storage device 8 at a pressure lower than the internal pressure of the high-pressure hydrogen storage device 7, and can be reused for power generation in the fuel cell 5.

[0095] This railway vehicle drive system 100b can be applied, for example, to a railway vehicle drive system for a train that runs on a route that is made up only of non-electrified sections and that has sections with continuous downward gradients, etc., that will fully charge the storage device 15.

[0096] The railway vehicle traction system 100b according to the second embodiment has been described above. EXAMPLES

[0097] Next, a description will be given of a railway vehicle traction system 100c according to a third embodiment. The railway vehicle traction system 100c is obtained by adding components related to a current collector to the railway vehicle traction system 100a according to the first embodiment.

[0098] Therefore, the following description of the third embodiment will focus only on the differences in functions, effects, etc. from the first embodiment, and will omit descriptions of the functions, effects, etc. that are common to the first embodiment.

[0099] Unlike the railway vehicle traction system 100b according to the second embodiment, the railway vehicle traction system 100c does not include components (15, 16) related to a power storage device.

[0100] (Configuration example of railway vehicle drive system 100c) First, a configuration example of a railway vehicle traction system 100c according to a third embodiment will be described with reference to Fig. 9. Fig. 9 is a diagram that illustrates an example of the configuration of the railway vehicle traction system 100c.

[0101] As described above, this railway vehicle drive system 100c is obtained by adding components related to the current collector, specifically, the current collector 17 and the current collector opening switch 18, to the railway vehicle drive system 100a of the first embodiment.

[0102] That is, the railway vehicle drive system 100c includes a current collector 17 and a current collector opening switch 18 as illustrated in FIG. 9, in addition to the components included in the railway vehicle drive system 100a illustrated in FIG.

[0103] The current collector 17 has contacts with the overhead line or the third rail and is a device for supplying electric power to the DC part of the main circuit of the railway vehicle. If the overhead line or the third rail supplies AC power, the current collector 17 may have a function of converting AC power into DC power.

[0104] This current collector 17 and the DC portion of the main circuit of the railway vehicle are electrically connected or disconnected by switching a current collector opening switch 18 by opening and closing it.

[0105] The controller 19 issues an operation command to the current collector opening switch 18 .

[0106] When the train related to the railway vehicle is running in an electrified section where an overhead line or a third rail is present, the current collector opening switch 18 is controlled by the controller 19 to electrically connect the current collector 17 to the DC part of the main circuit of the railway vehicle. In this case, the fuel cell opening switch 11 is controlled by the controller 19 to electrically disconnect the fuel cell 5 from the DC part of the main circuit of the railway vehicle.

[0107] On the other hand, when the train is running in a non-electrified section, the current collector opening switch 18 is controlled by the controller 19 to electrically disconnect the current collector 17 from the DC part of the main circuit of the railway vehicle. In this case, the fuel cell opening switch 11 is controlled by the controller 19 to electrically connect the fuel cell 5 to the DC part of the main circuit of the railway vehicle.

[0108] (Operation example of railway vehicle drive system 100c) Next, an example of the operation of the railway vehicle traction system 100c according to the third embodiment will be described with reference to the graphs shown in Fig. 10. Fig. 10 is a time chart showing an example of the operation of the railway vehicle traction system 100c.

[0109] The graphs shown in Figure 10, from top to bottom, represent the following 15 items: (a) The operating status of the train to which the rail vehicle relates (b) Example of change in power supply to power inverter 2 over time (c) Example of change over time in power consumption of auxiliary power supply 3 (d) Example of time change in the total power of the power inverter 2 and the auxiliary power supply 3 (e) State of fuel cell open switch 11 (f) Operating state of fuel cell 5 (g) Example of time change in internal pressure of auxiliary hydrogen storage device 8 (h) Example of change in hydrogen supply source over time (i) Operation state of auxiliary hydrogen storage device valve 10b (j) Operation state of the high-pressure hydrogen storage device valve 10a (k) Operational status of electrolyzer 6 (l) State of electrolysis device opening switch 12 (m) Operation status of compressor 13 (p) Electrification status of the route on which the train concerned runs (q) State of current collector opening switch 18

[0110] Among these, items (a) to (m) are the same as those in the first and second embodiments, and therefore the description thereof will be omitted.

[0111] Moreover, each graph in FIG. 10 shows an example of how the above items change over time when the route on which the train related to the railway vehicle runs includes a mixture of non-electrified sections and electrified sections.

[0112] At time t9, when the section in which the train is traveling that has been in a non-electrified section is switched to an electrified section, the railcars associated with the train can operate the current collector 17 to receive power from the overhead line and return surplus regenerative power to the overhead line. For this reason, the controller 19 of the railcar drive system 100c transmits a close command signal to the current collector opening switch 18 that is in an open state. This causes the current collector opening switch 18 to be in a closed state, electrically connecting the current collector 17 and the DC part of the main circuit of the railcar, and power is supplied to the DC part of the main circuit of the railcar from the overhead line or the third rail via the current collector 17.

[0113] Furthermore, at time t9, when the section the train is traveling in switches to an electrified section, the controller 19 of the railway vehicle traction system 100c sends an open command signal to the fuel cell open switch 11, which is in the closed state. This opens the fuel cell open switch 11, electrically cutting off the fuel cell 5 and the DC section of the main circuit. At this time, the controller 19 of the railway vehicle traction system 100a also sends a close command signal to the auxiliary hydrogen storage device valve 10b, which is in the open state. This closes the auxiliary hydrogen storage device valve 10b, cutting off the hydrogen supply path to the fuel cell 5, and the fuel cell 5, which was in operation, stops generating power.

[0114] At time t10, when the train stops powering and transitions to a coasting state, the power consumption of the power inverter 2 decreases and becomes zero again, and this decrease is reflected in the total power of the power inverter 2 and the auxiliary power supply 3.

[0115] At time t11, when the traction motor 1 of the railway vehicle begins regeneration again, the traction inverter 2 supplies the regenerative power to the DC section of the main circuit, and this change is reflected in the total power of the traction inverter 2 and the auxiliary power supply 3.

[0116] In this way, according to the railway vehicle drive system 100c, when the train related to the railway vehicle is traveling on a non-electrified section, excess regenerative power is converted into hydrogen by the electrolysis device 6, and the generated hydrogen is efficiently stored in the auxiliary hydrogen storage device 8 and can be reused for generating electricity in the fuel cell 5.

[0117] This railway vehicle drive system 100c can be applied, for example, to a railway vehicle associated with a train that runs on a line that has a mixture of non-electrified and electrified sections, and that is equipped with a fuel cell 5 but does not have a power storage device 15.

[0118] The railway vehicle traction system 100c according to the third embodiment has been described above. EXAMPLES

[0119] Next, a description will be given of a railway vehicle traction system 100d according to Example 4. This railway vehicle traction system 100d is obtained by adding components related to a power storage device and a power collection device to the railway vehicle traction system 100a according to Example 1.

[0120] Therefore, the following explanation of Example 4 will only focus on the aspects that differ from Examples 1 to 3 in terms of functions, effects, etc., and will omit explanations of the aspects that share functions, effects, etc. with at least one of Examples 1 to 3.

[0121] (Example of the configuration of the railway vehicle drive system 100d) First, a configuration example of a railway vehicle traction system 100d according to a fourth embodiment will be described with reference to Fig. 11. Fig. 11 is a diagram that illustrates an example of the configuration of the railway vehicle traction system 100d.

[0122] As described above, this railway vehicle drive system 100d is obtained by adding components related to the power storage device, specifically, the power storage device 15 and the power storage device opening switch 16 to the railway vehicle drive system 100a according to the first embodiment.

[0123] As described above, this railway vehicle drive system 100d is obtained by adding components related to the current collector, specifically, the current collector 17 and the current collector opening switch 18, to the railway vehicle drive system 100a of Example 1.

[0124] That is, in addition to the components of the railway vehicle drive system 100a illustrated in FIG. 1, the railway vehicle drive system 100d further includes a power storage device 15, a power storage device opening switch 16, a current collector 17, and a current collector opening switch 18, as illustrated in FIG. 11.

[0125] The power storage device 15 and the power storage device open switch 16 included in the railway vehicle drive system 100d are equivalent to those included in the railway vehicle drive system 100b according to Example 2. The current collector 17 and the current collector open switch 18 included in the railway vehicle drive system 100d are equivalent to those included in the railway vehicle drive system 100c according to Example 3. Therefore, an overview of these components will not be described.

[0126] When the train related to the railway vehicle is running on an electrified section where an overhead line or a third rail is present and the charge amount of the power storage device 15 is below a specified value, the power storage device opening switch 16 is controlled by the controller 19 to electrically connect the power storage device 15 to the DC section of the main circuit of the railway vehicle, as in the railway vehicle drive system 100c of Example 3.

[0127] On the other hand, when the power storage device 15 becomes fully charged while the train is regenerating in a non-electrified section, the power storage device opening switch 16 is controlled by the controller 19 to electrically disconnect the power storage device 15 from the DC part of the main circuit of the railway vehicle, similar to the railway vehicle drive system 100b according to the second embodiment. In this case, the electrolyzer opening switch 12 is controlled by the controller 19 to electrically connect the electrolyzer 6 to the DC part of the main circuit of the railway vehicle.

[0128] Furthermore, the railway vehicle traction system 100d includes a current control device 20, as illustrated in Fig. 11. This current control device 20 is equivalent to the current control device 20 illustrated in Fig. 2.

[0129] (Operation example of the railway vehicle drive system 100d) Next, an example of the operation of the railway vehicle traction system 100d according to the fourth embodiment will be described with reference to the graphs shown in Fig. 12. Fig. 12 is a time chart showing an example of the operation of the railway vehicle traction system 100d.

[0130] The graphs shown in FIG. 12, from top to bottom, represent the following 17 items: (a) The operating status of the train to which the rail vehicle relates (b) Example of change in power supply to power inverter 2 over time (c) Example of change over time in power consumption of auxiliary power supply 3 (d) Example of time change in the total power of the power inverter 2 and the auxiliary power supply 3 (e) State of fuel cell open switch 11 (f) Operating state of fuel cell 5 (g) Example of time change in internal pressure of auxiliary hydrogen storage device 8 (h) Example of change in hydrogen supply source over time (i) Operation state of auxiliary hydrogen storage device valve 10b (j) Operation state of the high-pressure hydrogen storage device valve 10a (k) Operational status of electrolyzer 6 (l) State of electrolysis device opening switch 12 (m) Operation status of compressor 13 (n) Example of change over time in the charging rate of the storage device 15 (o) State of the storage device opening switch 16 (p) Electrification status of the route on which the train concerned runs (q) State of current collector opening switch 18

[0131] Among these, the items (a) to (m) are the same as those in Examples 1 to 3. In addition, the items (n) and (o) are the same as those in Example 2, and the items (p) and (q) are the same as those in Example 3. Therefore, the description will be omitted.

[0132] Moreover, each graph in FIG. 12 shows an example of how the above items change over time when the route on which the train relating to the railway vehicle runs includes a mixture of non-electrified sections and electrified sections.

[0133] At time t11, when the section in which the train is traveling that has been in a non-electrified section is switched to an electrified section, the railcars associated with the train can operate the current collector 17 to receive power from the overhead line and return surplus regenerative power to the overhead line. For this reason, the controller 19 of the railcar drive system 100d transmits a close command signal to the current collector opening switch 18 that is in an open state. This causes the current collector opening switch 18 to be in a closed state, electrically connecting the current collector 17 and the DC part of the main circuit of the railcar, and power is supplied to the DC part of the main circuit of the railcar from the overhead line or the third rail via the current collector 17 and the power inverter 2.

[0134] As a result, the power supplied from the overhead line or the third rail to the DC part of the main circuit of the railway vehicle via the current collector 17 and the current control device 20 is supplied to the power storage device 15, causing the power storage device 15 to start charging. As a result, the charging rate of the power storage device 15, which had reached the lower limit threshold, rises again in accordance with the amount of power supply, and reaches the upper limit threshold at time t14.

[0135] At time t14, when the charging rate of the power storage device 15 reaches the upper limit threshold, an open command signal is sent from the controller 19 to the closed power storage device opening switch 16. This causes the power storage device opening switch 16 to enter an open state, electrically disconnecting the power storage device 15 from the DC part of the main circuit of the railway vehicle, and the power storage device 15 stops charging.

[0136] In this way, according to the railway vehicle drive system 100d, even if the power storage device 15 becomes fully charged due to a continuous downhill gradient or the like while the train is traveling in a non-electrified section, the regenerative power that has not been fully recovered by the power storage device 15 can be converted into hydrogen by the electrolysis device 6, and the generated hydrogen can be efficiently stored in the auxiliary hydrogen storage device 8 and reused for generating electricity in the fuel cell 5.

[0137] In other words, according to the railway vehicle drive system 100d, even if the power storage device 15 becomes fully charged due to a continuous downhill gradient while the train is traveling in a non-electrified section, the excess regenerative power that was not fully recovered by the power storage device 15 is supplied to the electrolysis device 6, and the hydrogen generated can be efficiently stored inside the auxiliary hydrogen storage device 8 at a pressure lower than the internal pressure of the high-pressure hydrogen storage device 7, and can be reused for power generation in the fuel cell 5.

[0138] This railway vehicle drive system 100d can be applied, for example, to a drive system for a railway vehicle associated with a train that runs on a route that includes a mixture of non-electrified and electrified sections and that includes sections with continuous downward gradients that require the storage device 15 to be fully charged.

[0139] The railway vehicle traction system 100d according to the fourth embodiment has been described above.

[0140] According to each of the above-mentioned embodiments, at least the following technical matters are included.

[0141] <Technical matters 1> A railroad vehicle drive system that drives a railroad vehicle using a fuel cell as a power source, A high-pressure hydrogen storage device that stores hydrogen filled at high pressure; A fuel cell that generates electricity using hydrogen as fuel; a water storage device for storing water generated when the fuel cell generates electricity; an electrolysis device that electrolyzes the water stored in the water storage device using surplus electricity; an auxiliary hydrogen storage device that stores hydrogen generated by electrolysis of water at a pressure lower than the hydrogen storage pressure of the high-pressure hydrogen storage device; Equipped with The hydrogen stored in the auxiliary hydrogen storage device is used to generate electricity in the fuel cell. Rail vehicle drive system.

[0142] <Technical matters 2> A first valve that controls hydrogen released from the high-pressure hydrogen storage device; a second valve for controlling hydrogen released from the auxiliary hydrogen storage device; Further equipped with The hydrogen discharged through the first valve and the hydrogen discharged through the second valve are combined and supplied to the fuel cell, and are used for generating electricity in the fuel cell. The railway vehicle drive system according to Technical Item 1 above.

[0143] <Technical matters 3> The railway vehicle drive system described in Technical Item 2 above, wherein the first valve and the second valve are controlled so as to preferentially send hydrogen stored in the auxiliary hydrogen storage device to the fuel cell when the fuel cell is generating electricity.

[0144] <Technical matters 4> A railway vehicle drive system as described in any one of technical items 1 to 3 above, wherein the first valve and the second valve are controlled so that the sum of hydrogen released from the high-pressure hydrogen storage device and the hydrogen released from the auxiliary hydrogen storage device is arbitrarily controlled, and hydrogen stored in the auxiliary hydrogen storage device is preferentially sent to the fuel cell when the fuel cell is generating electricity.

[0145] <Technical matters 5> 5. The railway vehicle drive system according to any one of Technical Items 1 to 4 above, further comprising a compressor for pressurizing hydrogen produced by electrolysis and sending the hydrogen to the auxiliary hydrogen storage device.

[0146] <Technical matters 6> 6. The railway vehicle drive system according to any one of Technical Items 1 to 5, wherein the water storage device further comprises an external water supply means other than the drainage water of the fuel cell.

[0147] <Technical matter 7> A railway vehicle driven by the railway vehicle drive system according to any one of Technical Items 1 to 6 above.

[0148] <Technical matters 8> A railroad vehicle drive method for driving a railroad vehicle using a fuel cell as a power source, comprising the steps of: The water produced when the hydrogen-fueled fuel cell generates electricity is stored in a water storage device. Electrolyzing the water stored in the water storage device using surplus electricity; The hydrogen generated by the electrolysis of water is stored in an auxiliary hydrogen storage device at a pressure lower than the hydrogen storage pressure of a high-pressure hydrogen storage device that stores hydrogen filled at high pressure; The hydrogen stored in the auxiliary hydrogen storage device is utilized for generating electricity in the fuel cell. A method for driving a railway vehicle.

[0149] <Technical matters 9> hydrogen discharged through a first valve that controls hydrogen discharged from the high-pressure hydrogen storage device and hydrogen discharged through a second valve that controls hydrogen discharged from the auxiliary hydrogen storage device are combined and supplied to the fuel cell; A railway vehicle drive method as described in Technical Item 8.

[0150] <Technical matters 10> A railway vehicle drive method as described in Technical Item 9, which controls the first valve and the second valve so as to preferentially send hydrogen stored in the auxiliary hydrogen storage device to the fuel cell when the fuel cell is generating electricity.

[0151] <Technical matters 11> A railway vehicle drive method described in any one of Technical Items 8 to 10, which controls the first valve and the second valve so that the sum of hydrogen released from the high-pressure hydrogen storage device and the hydrogen released from the auxiliary hydrogen storage device is an arbitrary amount.

[0152] <Technical matter 12> 12. The railway vehicle drive method according to any one of Technical Items 8 to 11, further comprising boosting hydrogen produced by electrolysis and feeding the hydrogen to the auxiliary hydrogen storage device.

[0153] <Technical matter 13> 13. The railway vehicle drive method according to any one of Technical Items 8 to 12, wherein the water storage device further comprises an external water supply means other than the drainage water of the fuel cell.

[0154] The above-mentioned embodiments, examples, and modifications are merely examples, and the present invention is not limited to these contents as long as the characteristics of the invention are not impaired. In addition, although various embodiments, examples, and modifications have been described above, the present invention is not limited to these contents. Other aspects that are conceivable within the scope of the technical idea of ​​the present invention are also included in the scope of the present invention.

[0155] The drawings are used to understand the invention and do not restrict the scope of the rights. In addition, in the above drawings, the control lines, information lines, etc. are examples that are considered necessary for explanation, and do not necessarily show all the control lines, information lines, etc. in the implementation. For example, it may be considered that almost all the components are actually connected to each other.

[0156] The above-described layout of the components of the railcar drive systems (100a, 100b, 100c, 100d) is merely an example. The layout of the components can be changed to an optimal layout in terms of the performance, processing efficiency, communication efficiency, and the like of the hardware and software included in the railcar drive systems (100a, 100b, 100c, 100d). [Explanation of symbols]

[0157] 1...Power motor 2...Power inverter 3…Auxiliary power supply device 4a…Filter capacitor 4b…Filter capacitor 5...fuel cell 6. Electrolysis device 7…High-pressure hydrogen storage device 8…Auxiliary hydrogen storage device 9…Water storage device 10a…High pressure hydrogen storage device valve 10b...Auxiliary hydrogen storage device valve 11…Fuel cell open switch 12...Electrolysis device opening switch 13...Compressor 14...External water supply means 15...Electricity storage device 16…Storage device release switch 17...Current collector 18...Current collector opening switch 19...Controller 20...Current control device 100a, 100b, 100c, 100d...Railway vehicle drive system

Claims

1. A railroad vehicle drive system that drives a railroad vehicle using a fuel cell as a power source, A high-pressure hydrogen storage device that stores hydrogen filled at high pressure; A fuel cell that generates electricity using hydrogen as fuel; a water storage device for storing water generated when the fuel cell generates electricity; an electrolysis device that electrolyzes the water stored in the water storage device using surplus electricity; an auxiliary hydrogen storage device that stores hydrogen generated by electrolysis of water at a pressure lower than the hydrogen storage pressure of the high-pressure hydrogen storage device; Equipped with The hydrogen stored in the auxiliary hydrogen storage device is used to generate electricity in the fuel cell. Rail vehicle drive system.

2. A first valve that controls hydrogen released from the high-pressure hydrogen storage device; a second valve for controlling hydrogen released from the auxiliary hydrogen storage device; Further equipped with The hydrogen discharged through the first valve and the hydrogen discharged through the second valve are combined and supplied to the fuel cell to be used for power generation by the fuel cell.

2. A rail vehicle drive system according to claim 1.

3. 3. The railway vehicle traction system according to claim 2, wherein the first valve and the second valve are controlled so as to preferentially send hydrogen stored in the auxiliary hydrogen storage device to the fuel cell when the fuel cell is generating electricity.

4. 4. The railway vehicle drive system according to claim 1, wherein the first valve and the second valve are configured to arbitrarily control the sum of hydrogen released from the high-pressure hydrogen storage device and hydrogen released from the auxiliary hydrogen storage device.

5. 5. The railway vehicle drive system according to claim 1, further comprising a compressor for pressurizing hydrogen produced by electrolysis and sending the hydrogen to the auxiliary hydrogen storage device.

6. 6. The railway vehicle drive system according to claim 1, wherein the water storage device further comprises an external water supply means other than drainage water of the fuel cell.

7. A railway vehicle driven by the railway vehicle drive system according to any one of claims 1 to 6.

8. A railroad vehicle drive method for driving a railroad vehicle using a fuel cell as a power source, comprising the steps of: The water produced when the hydrogen-fueled fuel cell generates electricity is stored in a water storage device. Electrolyzing the water stored in the water storage device using surplus electricity; The hydrogen generated by the electrolysis of water is stored in an auxiliary hydrogen storage device at a pressure lower than the hydrogen storage pressure of a high-pressure hydrogen storage device that stores hydrogen filled at high pressure; The hydrogen stored in the auxiliary hydrogen storage device is utilized for generating electricity in the fuel cell. A method for driving a railway vehicle.

9. hydrogen discharged through a first valve that controls hydrogen discharged from the high-pressure hydrogen storage device and hydrogen discharged through a second valve that controls hydrogen discharged from the auxiliary hydrogen storage device are combined and supplied to the fuel cell; A method for driving a railway vehicle according to claim 8.

10. 10. The railway vehicle drive method according to claim 9, further comprising controlling the first valve and the second valve so as to preferentially send hydrogen stored in the auxiliary hydrogen storage device to the fuel cell when the fuel cell is generating electricity.

11. 11. The railway vehicle drive method according to claim 8, further comprising controlling the first valve and the second valve so that the sum of hydrogen released from the high-pressure hydrogen storage device and hydrogen released from the auxiliary hydrogen storage device is an arbitrary amount.

12. The railway vehicle drive method according to any one of claims 8 to 11, further comprising the step of pressurizing hydrogen produced by electrolysis and feeding the hydrogen to the auxiliary hydrogen storage device.

13. The railway vehicle drive method according to any one of claims 8 to 12, wherein the water storage device further comprises an external water supply means other than drainage water of the fuel cell.

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