JP7516154B2 - Fuel cell system and power supply system - Google Patents

Description

Embodiments of the present invention relate to a fuel cell system and a power supply system.

A fuel cell system is connected to the commercial grid and consumer loads, and is equipped with a fuel cell and a power conditioning system (hereafter referred to as "PCS: Power Conditioning System"). The PCS converts the power generated by the fuel cell from direct current to alternating current that is used by the commercial grid and consumer loads. For a fuel cell to generate power, fuel and cooling water must be supplied to the fuel cell, and the fuel cell system must be equipped with additional auxiliary equipment for this purpose.

Until a fuel cell system starts generating power, it needs to be supplied with startup power, i.e., auxiliary power, from outside the fuel cell system. For this reason, by providing a power storage device inside the fuel cell system, auxiliary power can be secured even in the event of a power outage in the commercial grid, and the fuel cell can be started by starting the auxiliary equipment. On the other hand, once the fuel cell starts generating power, it can consume some of the power it generates itself, making it no longer necessary to supply power from an external commercial grid.

However, the larger the power generation capacity of a fuel cell system, the greater the startup power required, and the larger the capacity of the power storage device that supplies the startup power. This increases the volume and weight of the power storage device, resulting in higher costs.

JP 2014-179184 A

Therefore, the present embodiment aims to provide a fuel cell system that reduces the capacity of the power storage device and suppresses increases in volume and cost, and a power supply system that includes such a fuel cell system.

The fuel cell system according to this embodiment is a fuel cell system including a plurality of fuel cell power generation modules that receive startup power from a commercial grid, each of which includes a fuel cell that generates power using the supplied fuel, and which are divided into a first module group and a second module group. The fuel cell power generation modules included in the first module group include a power storage device that supplies stored power as startup power in the event of a power outage in the commercial grid, but the fuel cell power generation modules included in the second module group do not include the power storage device.

1 is a block diagram showing the overall configuration of a fuel cell system according to a first embodiment (a power storage device unit installed in an AC system). FIG. 4 is a flowchart illustrating the process of the startup process of the fuel cell system according to the first embodiment. 1 is a block diagram showing the overall configuration of a fuel cell system according to a first embodiment (a power storage device unit installed in a DC system); 1 is a block diagram showing the overall configuration of a fuel cell system according to a first embodiment (a power storage device unit installed in both a DC system and an AC system); FIG. 13 is a block diagram showing the overall configuration of a fuel cell system according to a second embodiment (a power storage device unit installed in an AC system). FIG. 11 is a flowchart illustrating the process of a startup process of a fuel cell system according to a second embodiment. FIG. 13 is a block diagram showing the overall configuration of a fuel cell system according to a second embodiment (power storage device unit installed in a DC system). FIG. 13 is a block diagram showing the overall configuration of a fuel cell system according to a second embodiment (power storage device unit installed in both a DC system and an AC system); FIG. 11 is a block diagram showing the overall configuration of a power supply system according to a third embodiment. FIG. 11 is a flowchart illustrating the process contents of a startup process of a power supply system according to a third embodiment. FIG. 13 is a block diagram showing the overall configuration of a fuel cell system according to a fourth embodiment (power storage device unit installed in an AC system). FIG. 13 is a flowchart illustrating the details of a startup process of a fuel cell system according to a fourth embodiment. FIG. 13 is a block diagram showing the overall configuration of a fuel cell system according to a fourth embodiment (power storage device unit installed in a DC system). FIG. 13 is a block diagram showing the overall configuration of a fuel cell system according to a fourth embodiment (power storage device unit installed in both DC and AC systems); FIG. 13 is a block diagram showing the overall configuration of a fuel cell system according to a fourth embodiment (electricity storage device-installed type).

Below, an embodiment of a fuel cell system will be described in detail with reference to the drawings. In the following description, components having substantially the same functions and configurations will be given the same reference numerals, and duplicated descriptions will be given only when necessary.

First Embodiment
Fig. 1 is a block diagram showing the overall configuration of a fuel cell system 1 according to a first embodiment. As shown in Fig. 1, the fuel cell system 1 in this embodiment includes a control device 10, a fuel cell power generation module 12 included in a first module group, and a fuel cell power generation module 14 included in a second module group. That is, in this embodiment, the fuel cell system 1 has a modular configuration divided into a plurality of fuel cell power generation modules 12 and 14, and each of the divided fuel cell power generation modules 12 and 14 functions as a single fuel cell system. For example, in the case of a fuel cell system 1 with a rated capacity of 1 MW, one of the fuel cell power generation modules 12 and 14 has a rated capacity of 100 kW, and the fuel cell system 1 is made up of 10 of these modules.

The control device 10 performs the necessary control of the fuel cell power generation modules 12 and 14. For example, the control device 10 is realized by a computer that sends commands to the fuel cell power generation modules 12 and 14, and a communication unit that can communicate with each of the fuel cell power generation modules 12 and 14. The computer of the control device 10 further includes, for example, a processing memory unit that manages the power generation status of each of the fuel cell power generation modules 12 and 14 and stores the power generation status, and transmits appropriate commands to the fuel cell power generation modules 12 and 14 based on the obtained power generation status. In addition, the control device 10 connects the control device 10 and the fuel cell power generation modules 12 and 14 by wired or wireless communication via the communication unit, thereby realizing a communication function between the two. The connection method is electrical, mechanical, or a combination of these.

The fuel cell power generation modules 12 and 14 are connected to a commercial grid, and the power generated by the fuel cell power generation modules 12 and 14 is supplied to consumer loads via the commercial grid. In addition, when the fuel cell power generation modules 12 and 14 are started from a stopped state, startup power is supplied from the commercial grid to the fuel cell power generation modules 12 and 14. Therefore, startup power can be supplied to the fuel cell power generation modules 12 and 14 provided in this fuel cell system 1 to start them up simultaneously.

The fuel cell power generation module 12, which is the first module group, includes a module control device 20, auxiliary equipment 22, a power storage unit 24, a PCS 26, and a fuel cell 28. On the other hand, the fuel cell power generation module 14, which is the second module group, includes a module control device 20, auxiliary equipment 22, a PCS 26, and a fuel cell 28. In other words, the fuel cell power generation module 12 of the first module group includes a power storage unit 24, and the fuel cell power generation module 14 of the second module group does not include a power storage unit 24. The components that make up the fuel cell power generation modules 12 and 14 are connected to each other in a form that allows power to be supplied from the commercial grid.

In the fuel cell system 1 shown in FIG. 1, the first module group has one fuel cell power generation module 12, and the second module group has one or more fuel cell power generation modules 14.

In the fuel cell power generation module 12 of the first module group, the module control device 20 performs necessary control over the auxiliary equipment 22, the power storage unit 24, the PCS 26, and the fuel cell 28. In the fuel cell power generation module 14 of the second module group, the module control device 20 performs necessary control over the auxiliary equipment 22, the PCS 26, and the fuel cell 28 in its own fuel cell power generation module 14. For example, the module control device 20 is realized by a computer that transmits commands to the auxiliary equipment 22, the power storage unit 24, the PCS 26, and the fuel cell 28, and a communication unit that can communicate with the control device 10. The computer of the module control device 20 further includes, for example, a processing memory unit that manages the start-up status of the auxiliary equipment 22, the storage or power supply status of the power storage unit 24, the current conversion status of the PCS 26, and the power generation status of the fuel cell 28, and stores these various statuses, and transmits the obtained status to the control device 10 in a timely manner, and receives necessary commands from the control device 10 via the communication unit, etc. The module control device 20 connects the fuel cell power generation modules 12 and 14 to the control device 10 via a communication unit, either by wire or wireless communication, and the connection method can be electrical, mechanical, or a combination of these.

The auxiliary equipment 22 supplies the fuel cell 28 with fuel, such as hydrogen, air, and cooling water, necessary for the fuel cell 28 to generate electricity. The auxiliary equipment 22 is realized, for example, by a blower or a pump. When the fuel cell power generation modules 12 and 14 are generating electricity, the auxiliary equipment 22 may be supplied with its operating power from a commercial system, or may be supplied with electricity generated by the fuel cell 28.

When the fuel cell power generation modules 12 and 14 are started from a stopped state, startup power is supplied from the commercial grid. Therefore, if the commercial grid is experiencing a power outage, startup power cannot be supplied to the auxiliary equipment 22 of the fuel cell power generation module 14. On the other hand, startup power can be supplied from the power storage unit 24 to the auxiliary equipment 22 of the fuel cell power generation module 12 even if the commercial grid is experiencing a power outage.

The power storage device 24 unit provided in the fuel cell power generation module 12 is installed in the AC system of the fuel cell power generation module 12, and supplies startup power to the auxiliary equipment 22 in the event of a power outage in the commercial system. The power storage device unit 24 is realized, for example, by a storage battery. This storage battery can be composed of, for example, a lead storage battery, an alkaline storage battery, or a lithium ion storage battery, and can be reused by storing electricity again after discharging. Furthermore, this power storage device unit 24 supplies startup power to at least the auxiliary equipment 22, but may also supply startup power to the module control device 20 and the PCS 26 as necessary.

For example, the power storage unit 24 can receive power from a commercial grid and store it. The power storage unit 24 can also receive power generated by the fuel cell 28 and store it. In this embodiment, the power storage unit 24 has a capacity necessary to cover the startup power required to start the fuel cell power generation module 12 from a stopped state. Preferably, the capacity of the power storage unit 24 is equal to or slightly larger than the startup power capacity required to start the fuel cell power generation module 12. This is because having a capacity that is greater than necessary for the power storage unit 24 would result in the weight and manufacturing costs of the power storage unit 24 increasing more than necessary.

The PCS 26 converts the power generated by the fuel cell 28 from direct current to alternating current. The consumer's loads, such as household power sources and mechanical equipment, typically use alternating current. On the other hand, the power generated by the fuel cell 28 is typically direct current. Therefore, when the power generated by the fuel cell power generation modules 12 and 14 is supplied to the consumer's loads via the commercial system, it is supplied via the PCS 26. In this specification, in the power system including the commercial system and the fuel cell system 1, the system on the commercial system side of the PCS 26 is called the "AC system," and the system on the fuel cell side of the PCS 26 is called the "DC system."

Therefore, in the embodiment shown in FIG. 1, since the power storage unit 24 is installed closer to the commercial system than the PCS, it can be said that the power storage unit 24 is present in the AC system, and the fuel cell system 1 according to this embodiment can be said to be "power storage unit AC system installed type."

The fuel cell 28 generates electricity by receiving fuel such as hydrogen or air, cooling water, etc. from the auxiliary equipment 22, and supplies the electricity to the consumer's load via the commercial system. In this embodiment, for example, the fuel cell 28 may generate electricity steadily and supply electricity, or, in the event of a power outage in the commercial system, may supply electricity to a specific consumer's load via a supply line independent of the commercial system. The fuel cell 28 is a device that generates electrical energy by electrochemically reacting, for example, hydrogen with an oxidant such as oxygen, and can be realized, for example, by a hydrogen-oxygen fuel cell.

Next, various processes executed in the fuel cell system 1 according to this embodiment will be described in detail. FIG. 2 is a diagram showing a flowchart explaining the fuel cell system startup process executed in the fuel cell system 1 according to this embodiment. This fuel cell system startup process is a process executed when the control device 10 starts up the stopped fuel cell system 1 in a situation where power cannot be supplied from the commercial grid. In other words, this process is executed to sequentially start up the stopped fuel cell power generation modules 12 and 14 and enable the fuel cell system 1 to generate power without receiving a supply of startup power from the commercial grid.

As shown in FIG. 2, in this fuel cell system startup process, the fuel cell system 1 uses the power stored in the power storage unit 24 as startup power to start up the fuel cell power generation module 12 included in the first module group (step S10). In this embodiment, for example, when it becomes necessary to start up the fuel cell system under a situation in which startup power cannot be supplied from the commercial grid, the control device 10 starts up the fuel cell power generation module 12 by sending a command to the fuel cell power generation module 12 to start it up.

For the fuel cell power generation module 12 to start up, the module control device 20 of the fuel cell power generation module 12 receives a command from the control device 10 to start up the fuel cell power generation module 12, and then starts up the auxiliary equipment 22 using the power stored in the power storage unit 24. After the auxiliary equipment 22 has started up, the auxiliary equipment 22 supplies fuel, cooling water, etc. to the fuel cell 28, starting up the fuel cell 28. Once the fuel cell 28 has started up and is in a state where it can supply power to the commercial grid and to the fuel cell power generation module 14 itself, the fuel cell power generation module 12 is considered to have started up.

Next, the control device 10 determines which fuel cell power generation module 14 to start from among the fuel cell power generation modules 14 included in the second module group (step S12). In this embodiment, the control device 10 selects one of the fuel cell power generation modules 14 from among the multiple fuel cell power generation modules 14 included in the second module group.

The fuel cell power generation module 14 included in the second module group does not have a power storage unit 24, and therefore needs to be supplied with startup power from an external source in order to start up. Therefore, while it is necessary to receive startup power from a commercial grid, for example, during a power outage, when startup power cannot be received from the commercial grid, the fuel cell power generation module 14 can start up without receiving startup power from the commercial grid by receiving startup power from the fuel cell power generation module 12 included in the first module group, which is already in a power generation state.

Next, the control device 10 supplies startup power to the fuel cell power generation module 14 determined in step S12 to start it up (step S14). The process of starting up the fuel cell power generation module 14 after receiving the startup power supply is the same as the process of starting up the fuel cell power generation module 12, so it will not be described in detail here.

The number of fuel cell power generation modules 14 included in the second module group started in steps S12 and S14 is not limited to one, and multiple fuel cell power generation modules 14 may be started at once. In other words, if the power generated by the fuel cell power generation module 12 included in the first module group is sufficient to cover the startup power of the auxiliary machinery 22 in two or more fuel cell power generation modules 14 included in the second module group, multiple fuel cell power generation modules 14 may be started according to the available power.

Next, the control device 10 determines whether all fuel cell power generation modules 12 and 14 included in the first and second module groups have been started (step S16). In other words, it determines whether all fuel cell power generation modules 12 and 14 included in this fuel cell system 1 have been started.

If all fuel cell power generation modules are started (step S16: Yes), the fuel cell system startup process according to this embodiment ends. On the other hand, if all fuel cell power generation modules are not started (step S16: No), the control device 10 returns to step S12 and repeats the above-mentioned process until all fuel cell power generation modules are started.

When the fuel cell power generation modules 12 are started and in a power generating state, it is possible to adjust the number of fuel cell power generation modules 14 to be started in step S14 according to the capacity of the generated power. For example, if two fuel cell power generation modules 14 can be started with the power supplied by one started fuel cell power generation module 12, it may be decided to start two fuel cell power generation modules 14 in step S12, and two fuel cell power generation modules 14 may be started in step S14.

In addition, for example, when one fuel cell power generation module 12 and one fuel cell power generation module 14 are in a power generating state, it is possible to start up the two fuel cell power generation modules 14 by using the supplied power as startup power.

On the other hand, for example, if one fuel cell power generation module 12 and two fuel cell power generation modules 14 are in a power generating state, it is possible to use the supplied power as startup power to start up three fuel cell power generation modules 14, and it is also possible to start up four fuel cell power generation modules 14. In other words, the number of fuel cell power generation modules 14 to be started up in step S14 can be set arbitrarily based on the power capacity generated by the fuel cell power generation modules 12 and 14 that have been started up and are in a power generating state, and it can be considered that at least one fuel cell power generation module 14 is started up.

Next, a modified example of the fuel cell system 1 according to the first embodiment will be described with reference to FIG. 3. FIG. 3 is a block diagram showing the overall configuration of the fuel cell system 1 according to the first embodiment, and shows an example of a "power storage unit DC system installation type." That is, this is an embodiment in which the power storage unit 24 is installed closer to the fuel cell than the PCS 26 in the fuel cell power generation module 12.

In this embodiment, the power supplied from the power storage unit 24 to the auxiliary equipment 22 passes through the PCS 26, so the power supplied by the power storage unit 24 is direct current, but is converted to alternating current in the PCS 26, and the alternating current is supplied to the auxiliary equipment 22.

The fuel cell system startup process executed in the fuel cell system 1 shown in FIG. 3 is similar to that shown in FIG. 2, so it will not be described in detail here.

Next, another modified example of the fuel cell system 1 according to the first embodiment will be described with reference to FIG. 4. FIG. 4 is a block diagram showing the overall configuration of the fuel cell system according to the first embodiment, and shows an example of a "power storage unit installed in both the DC and AC systems." That is, this is an embodiment in which the power storage unit 24 is installed in both the fuel cell side of the PCS 26 and the commercial system in the fuel cell power generation module 12.

This embodiment is a modified example that combines the fuel cell system 1 of FIG. 1 and the fuel cell system 1 of FIG. 3 described above, and startup power is supplied to the auxiliary machinery 22 from two power storage units 24. In addition to this, since the fuel cell power generation module 12 is equipped with two power storage units 24, for example, even if one of the power storage units 24 is unable to supply power to the auxiliary machinery 22, the other power storage unit 24 can still supply power to the auxiliary machinery 22, providing redundancy for the startup of the fuel cell power generation module 12.

In other words, as is clear from the configuration of the fuel cell system 1 in Figures 1, 3, and 4 described above, the fuel cell power generation module 12 included in the first module group according to this embodiment only needs to have at least one of a power storage unit 24 connected to a line to which the commercial grid is connected and a power storage unit 24 connected to the output line of the fuel cell 28.

The fuel cell system startup process executed in the fuel cell system 1 according to this embodiment is similar to that shown in FIG. 2 and will not be described in detail here.

As described above, according to the fuel cell system 1 of this embodiment, the fuel cell power generation module 12 included in the first module group is provided with a power storage unit 24, and when the stopped fuel cell system 1 must be started up in a situation where power cannot be supplied from the commercial grid, the fuel cell power generation module 12 is first started up using the power stored in the power storage unit 24. This makes it possible to start up the fuel cell power generation module 12 with a smaller power storage capacity than starting up the entire fuel cell system 1. Then, the power generated by the started fuel cell power generation module 12 is used as start-up power to start up the fuel cell power generation modules 14 included in the second module group in sequence, and finally all of the fuel cell power generation modules 14 can be started up. This eliminates the need to provide a power storage device with a large power storage capacity as in the past, and makes it possible to reduce the volume, weight, and cost of the installed power storage device.

Second Embodiment
The fuel cell system 1 according to the second embodiment is configured such that the number of fuel cell power generation modules 12 belonging to the first module group is increased by one to a total of two fuel cell power generation modules 12, thereby shortening the time required to start up the fuel cell system 1 and improving the redundancy and reliability of the fuel cell system 1, thereby ensuring stable start-up of the fuel cell system 1. The following describes the differences from the first embodiment described above.

Figure 5 is a block diagram showing the overall configuration of a fuel cell system according to the second embodiment. As shown in Figure 5, the fuel cell system 1 in this embodiment includes a control device 10, two fuel cell power generation modules 12 belonging to a first module group, and a fuel cell power generation module 14 belonging to a second module group.

In this embodiment, the two fuel cell power generation modules 12 belonging to the first module group can start up independently by using the power stored in each of the power storage units 24 as startup power. In this embodiment, the number of fuel cell power generation modules 12 belonging to the first module group is two, so the total startup power capacity of the first module group is approximately twice that of the first embodiment.

In the embodiment shown in FIG. 5, the power storage unit 24 is installed closer to the commercial system than the PCS, so the power storage unit 24 can be said to be in the AC system, and this embodiment can be said to be a fuel cell system 1 with a "power storage unit installed in the AC system."

Next, the fuel cell system startup process executed in the fuel cell system 1 according to this embodiment will be described with reference to FIG. 6. The fuel cell system startup process shown in FIG. 6 corresponds to the fuel cell system startup process shown in FIG. 2 described above, but differs in that the two fuel cell power generation modules 12 are started up first.

As shown in FIG. 6, in this fuel cell system startup process, the power stored in the power storage unit 24 is used as startup power to start up the fuel cell power generation modules 12 included in the first module group (step S20). In this embodiment, as described above, since there are two fuel cell power generation modules 12, the control device 10 transmits commands to start up the two fuel cell power generation modules 12.

The command sent by the control device 10 described above may, for example, start up the two fuel cell power generation modules 12 simultaneously, or start them in sequence with a time lag, or, in the case where one of the fuel cell power generation modules 12 is faulty, only one of the fuel cell power generation modules 12 may be started.

Next, the control device 10 determines which fuel cell power generation modules 14 to start from among the fuel cell power generation modules 14 included in the second module group (step S22). In this embodiment, the control device 10 selects any two fuel cell power generation modules 14 from among the multiple fuel cell power generation modules 14 included in the second module group.

Next, the control device 10 supplies startup power to the fuel cell power generation module 14 determined in step S22 to start it up (step S24). The control device 10 then determines whether all fuel cell power generation modules 12 and 14 included in the first and second module groups have started up (step S26). The processing of steps S24 and S26 is similar to the processing of steps S14 and S16 in the first embodiment described above.

When two fuel cell power generation modules 12 are started and in a power generating state, it is possible to adjust the number of fuel cell power generation modules 14 to be started in step S24 according to the capacity of the generated power. For example, if three fuel cell power generation modules 14 can be started with the power supplied by the two started fuel cell power generation modules 12, it may be decided in step S22 to start three fuel cell power generation modules 14, and the three fuel cell power generation modules 14 may be started in step S24. On the other hand, if only one fuel cell power generation module 14 can be started with the power supplied by the two started fuel cell power generation modules 12, it may be decided in step S22 to start one fuel cell power generation module 14, and the one fuel cell power generation module 14 may be started in step S24.

As described above, the first module group of the fuel cell system 1 according to this embodiment has a total of two fuel cell power generation modules 12, and therefore can supply approximately twice as much power to the second module group. This means that it is expected that the time required to start up all of the fuel cell power generation modules 14 belonging to the second module group will be shorter than in the first embodiment, and the fuel cell system 1 can be started up more quickly.

Next, a modified example of the fuel cell system 1 according to the second embodiment will be described with reference to FIG. 7. FIG. 7 is a block diagram showing the overall configuration of the fuel cell system according to the second embodiment, and shows an example of a "power storage unit installed in a DC system." In other words, this is an embodiment in which the power storage unit 24 is installed closer to the fuel cell than the PCS 26, and corresponds to FIG. 3 in the first embodiment described above.

As in the first embodiment, the power supplied from the power storage unit 24 to the auxiliary equipment 22 passes through the PCS 26, so the power supplied by the power storage unit 24 is direct current, but is converted to alternating current in the PCS 26, and the alternating current is supplied to the auxiliary equipment 22.

The fuel cell system startup process executed in the fuel cell system 1 shown in FIG. 7 is similar to that shown in FIG. 6, so it will not be described in detail here.

Next, another modified example of the fuel cell system 1 according to the second embodiment will be described with reference to FIG. 8. FIG. 8 is a block diagram showing the overall configuration of the fuel cell system according to the second embodiment, and shows an example of a "power storage unit installed in both the DC and AC systems." That is, in each fuel cell power generation module 12, the power storage unit 24 is installed on both the fuel cell side of the PCS 26 and on the commercial system, and corresponds to FIG. 4 in the first embodiment described above.

As with the first embodiment described above, even if, for example, one of the power storage units 24 in the same fuel cell power generation module 12 is unable to supply power to the auxiliary equipment 22, the other power storage unit 24 can still supply power to the auxiliary equipment 22, providing redundancy in the startup of the fuel cell power generation module 12.

The fuel cell system startup process executed in the fuel cell system 1 according to this embodiment is similar to that shown in FIG. 6 and will not be described in detail here.

In the second embodiment, three types have been described. That is, the three types are "electricity storage unit installed in AC system", "electricity storage unit installed in DC system", and "electricity storage unit installed in both DC system and AC system". In addition, for example, in one fuel cell power generation module 12, the electricity storage unit 24 may be arranged in the DC system, but in the other fuel cell power generation module 12, it may be arranged in the AC system, or vice versa. Furthermore, one fuel cell power generation module 12 may have only one electricity storage unit 24, but the other fuel cell power generation module 12 may have two electricity storage units 24. Therefore, in this embodiment, there is no particular restriction on the location where the electricity storage unit 24 is arranged, and it can be modified in any manner.

In addition, in the second embodiment, the first module group is composed of two fuel cell power generation modules 12, but the first module group may be composed of multiple fuel cell power generation modules 12, such as three or four. This can further increase redundancy when starting up the fuel cell system 1 in a situation where startup power cannot be supplied from the commercial grid.

Third Embodiment
In the third embodiment, an emergency power storage device 16 as shown in Fig. 9 is additionally provided to the fuel cell system 1 according to the first and second embodiments described above to configure a power supply system 2 so that power can be supplied to a consumer load via a commercial grid even when the fuel cell system 1 is inoperable. In the following, the power supply system 2 according to the third embodiment will be described as a modification of the first embodiment, but it is also possible to realize the power supply system 2 according to the third embodiment by modifying the second embodiment.

Figure 9 is a block diagram explaining the overall configuration of the power supply system 2 according to the third embodiment. As shown in this Figure 9, the power supply system 2 according to the third embodiment includes an emergency power storage device 16 outside the fuel cell system 1. In this embodiment, this emergency power storage device 16 is connected to a commercial grid that supplies power to consumer loads and supplies startup power to the fuel cell power generation modules 12 and 14.

The emergency power storage device 16 supplies emergency power to the consumer load from the commercial grid when, for example, the power storage device unit 24 is unable to supply power to the auxiliary device 22 due to a malfunction or other reason. The emergency power storage device 16, like the power storage device unit 24, is realized by, for example, a storage battery, which may be a lead storage battery, an alkaline storage battery, or a lithium ion storage battery, and may be capable of being reused by storing electricity again after discharging. The storage capacity of the emergency power storage device 16 may be larger than the storage capacity of the power storage device unit 24, assuming that emergency power will be supplied to multiple consumer loads.

Next, various processes executed in the power supply system 2 according to this embodiment will be described in detail. FIG. 10 is a diagram showing a flowchart explaining the power supply system startup process executed in the power supply system 2 according to this embodiment. This power supply system startup process is a process executed when the control device 10 starts up the power supply system 2. In this embodiment, for example, this process is executed by the control device 10 starting up the fuel cell power generation module 12 when starting up the power supply system 2.

As shown in FIG. 10, in this fuel cell system startup process, the control device 10 determines whether the fuel cell system 1 is operable (step S30). If the fuel cell system 1 is operable (step S30: Yes), the above-mentioned fuel cell system startup process is started (step S32). The fuel cell system startup process is as shown in steps S10 to S16 of FIG. 2 in the first embodiment, or steps S20 to S26 of FIG. 6 in the second embodiment.

On the other hand, if the fuel cell system 1 is not operable due to a malfunction of the fuel cell system 1 or other reasons (step 30: No), power is supplied from the emergency power storage device 16 to the commercial grid (step S34) to ensure power for the consumer's load.

As described above, according to the power supply system 2 of this embodiment, even if the fuel cell system 1 is inoperable for some reason, the power stored in the emergency power storage device 16 can be supplied to the consumer's load from the commercial grid. Therefore, even if the fuel cell system 1 is inoperable, it can still function as the power supply system 2 for supplying power to consumers, and can provide improved redundancy compared to the fuel cell system 1 described in the first and second embodiments.

The emergency power storage device 16 may be configured to supply startup power to the auxiliary equipment 22 of the fuel cell power generation module 12 via the commercial grid to start up the auxiliary equipment 22. This provides higher redundancy for the startup of the fuel cell power generation module 12 and the startup of the fuel cell system 1, and ensures the stability of the startup of the fuel cell system 1.

In addition, for example, if only the fuel cell power generation module 12 in the fuel cell system 1 cannot be started, and the fuel cell power generation module 14 can be started if startup power is supplied to the auxiliary equipment from the outside, the fuel cell system 1 can be started by supplying startup power from the emergency power storage device 16 through the commercial grid to the fuel cell power generation module 14, and the power of the emergency power storage device 16 is not limited to being used only for consumer loads.

In FIG. 9, the fuel cell system 1 is illustrated as being "a power storage unit installed in an AC system." However, the fuel cell system 1 of the power supply system 2 equipped with the emergency power storage device 16 may be equipped with a fuel cell system 1 of "a power storage unit installed in a DC system" or "a power storage unit installed in both a DC system and an AC system." In other words, the power supply system 2 according to the third embodiment can be applied to all of the above-mentioned modifications of the first embodiment and the second embodiment.

In addition, in FIG. 9, the emergency power storage device 16 is illustrated as being outside the fuel cell system 1, but in reality, the emergency power storage device 16 may or may not be physically separated from the fuel cell system 1, and there are no restrictions on the location where it is installed.

Fourth Embodiment
The fuel cell system 1 according to the fourth embodiment is the fuel cell system 1 according to the first, second or third embodiment described above, in which a fuel cell power generation module 12 belonging to a first module group and a fuel cell power generation module 14 belonging to a second module group are connected via a switch, making it possible to supply startup power to each of the fuel cell power generation modules 12 and 14 without going through a commercial grid. In the following, the fuel cell system 1 according to the fourth embodiment will be described as a modification of the first embodiment, but it is also possible to realize the fuel cell system 1 according to the fourth embodiment by modifying the second or third embodiment.

Figure 11 is a block diagram showing the overall configuration of a fuel cell system according to the fourth embodiment. As shown in Figure 11, the fuel cell system 1 in this embodiment includes a control device 10, a fuel cell power generation module 12 belonging to a first module group, and a fuel cell power generation module 14 belonging to a second module group, and all of the fuel cell power generation modules 12 and 14 are connected to each other via a switch 30. In other words, the switch 30 selectively connects the power storage device unit 24 to one of the multiple fuel cell power generation modules 12 and 14.

As shown in FIG. 11, in this embodiment, all fuel cell power generation modules 12 and 14 are connected to each other, so that the power of the power storage device unit 24 in the fuel cell power generation module 12 can be supplied to any of the fuel cell power generation modules 14 by selecting the connection of the switch 30. Therefore, in this embodiment, not only the fuel cell power generation module 12 included in the first module group that has the power storage device unit 24, but also the fuel cell power generation module 14 included in the second module group that does not have the power storage device unit 24 can be supplied with startup power and become the first fuel cell power generation module to be started up.

Therefore, if there is a failure in a component of the fuel cell power generation module 12 other than the power storage unit 24 (e.g., the auxiliary equipment 22, etc.), but there is no defect in the power storage unit 24 and power can be supplied, startup power can be supplied to the fuel cell power generation module 14 other than the fuel cell power generation module 12 in which the power storage unit 24 is located, and the fuel cell power generation module 14 that receives the startup power will start up, and by starting up the other fuel cell power generation modules 14, the startup of the fuel cell system 1 can be ensured.

For this reason, in this embodiment, the control device 10 acquires operation capability information from each of the fuel cell power generation modules 12 and 14, indicating whether there is a malfunction or whether operation is possible, and is able to determine which of the fuel cell power generation modules 12 and 14 should be supplied with startup power. In other words, the control device 10 determines which of the fuel cell power generation modules 12 and 14 should be started, including whether startup is actually possible, based on the operation capability information.

Next, various processes executed in the fuel cell system 1 according to this embodiment will be described in detail. FIG. 12 is a diagram showing a flowchart explaining the fuel cell system startup process executed in the fuel cell system 1 according to this embodiment. This fuel cell system startup process is a process executed when the control device 10 starts up the fuel cell system 1.

As shown in FIG. 12, in the fuel cell system startup process, the fuel cell power generation modules 12 and 14 to which the power stored in the power storage unit 24 will be supplied as startup power are determined (step S40). In this embodiment, the fuel cell power generation module 12 included in the first module group can be determined as the fuel cell power generation module to be started first, or the fuel cell power generation module 14 included in the second module group can be determined as the fuel cell power generation module to be started first.

Next, the control device 10 controls the switch 30 to connect the power storage unit 24 to the determined fuel cell power generation module 12 or 14 (step S42). Then, the power stored in the power storage unit 24 via the switch 30 is supplied to the connected fuel cell power generation module 12 or 14 as startup power, and the fuel cell power generation module 12 or 14 starts up (step S44).

Next, the control device 10 determines which fuel cell power generation module to start from among the fuel cell power generation modules 12 or 14 included in the first or second module group (step S46). Then, the control device 10 supplies the power generated by the fuel cell power generation module 12 or 14 that is in a power generating state as startup power to the determined fuel cell power generation module 14 (step S48). When supplying startup power, it may be supplied from the commercial grid or via the switch 30, and the method is not limited.

Next, the control device 10 determines whether all fuel cell power generation modules 12 and 14 included in the first and second module groups have been started (step S50). Here, fuel cell power generation modules 12 and 14 that are determined to be unable to be started due to a malfunction or the like are excluded from the determination of whether all have been started.

As in the first embodiment described above, the fuel cell system 1 of this embodiment can be realized as a "power storage unit installed in a DC system" fuel cell system 1 in which the power storage unit 24 is present on the DC system side as shown in FIG. 13, or as a "power storage unit installed in both a DC system and an AC system" fuel cell system 1 in which the power storage unit 24 is present on both the AC system and the DC system as shown in FIG. 14. The fuel cell system startup process is the same as that of FIG. 12.

In this embodiment, the power storage unit 24 does not necessarily have to be installed inside the fuel cell power generation module 12. In other words, the power storage unit 24 can also be installed outside the fuel cell power generation module 12.

Figure 15 shows the internal configuration of a fuel cell system 1 in which, instead of installing the power storage unit 24 inside the fuel cell power generation module 12, the power storage device 18 is installed outside the fuel cell power generation module 12. In the modified example shown in Figure 15, the power storage device unit 24 installed in the fuel cell power generation module 12 is taken outside the fuel cell power generation module 12 and installed as the power storage device 18. In this case, the control device 10 obtains operability information indicating whether the fuel cell power generation modules 12 and 14 are operable or not, and selects the fuel cell power generation modules 12 and 14 that are operable based on this operability information. Then, the switch 30 is controlled so that startup power is supplied from the power storage device 18 to the selected fuel cell power generation modules 12 and 14.

As described above, according to the fuel cell system 1 of this embodiment, the fuel cell power generation module 12 can be started up by the power storage unit 24 that is appropriate for the size of the fuel cell power generation module 12, and the entire fuel cell system 1 can be started up. In addition, the volume and weight of the power storage unit 24 can be reduced compared to the size of the fuel cell system 1, thereby enabling cost reductions, etc.

Although several embodiments have been described above, these embodiments are presented only as examples and are not intended to limit the scope of the invention. The novel apparatus and method described in this specification can be embodied in various other forms. In addition, various omissions, substitutions, and modifications can be made to the forms of the apparatus and method described in this specification without departing from the spirit of the invention. The appended claims and their equivalents are intended to include such forms and modifications that fall within the scope and spirit of the invention.

1... fuel cell system, 2... power supply system, 10... control device, 12... fuel cell power generation module included in first module group, 14... fuel cell power generation module included in second module group, 16... emergency power storage device, 18... power storage device, 20... module control device, 22... auxiliary equipment, 24... power storage device unit, 26... PCS (power conditioner), 28... fuel cell, 30... switch

Claims (8)

A fuel cell system including a plurality of fuel cell power generation modules, the startup power of which is supplied from a commercial grid;
an emergency power storage device connected to the commercial grid that supplies the startup power to the fuel cell system, and that supplies stored power to a consumer from the commercial grid as emergency power when the fuel cell system is inoperable;
A power supply system comprising:
The fuel cell system includes:
Each of the plurality of fuel cell power generation modules includes a fuel cell that generates power using a supplied fuel,
the plurality of fuel cell power generation modules are divided into a first module group and a second module group, the fuel cell power generation modules included in the first module group are provided with a power storage device that supplies stored power as startup power in the event of a power outage in the commercial grid, and the fuel cell power generation modules included in the second module group are not provided with the power storage device,
The power storage device in the fuel cell power generation module included in the first module group includes a first power storage unit connected to a line to which a commercial grid of the fuel cell power generation module is connected, and a second power storage unit connected to an output line of the fuel cell of the fuel cell power generation module.
Power supply system. A control device for controlling the start-up of the plurality of fuel cell power generation modules is further provided,
2. The power supply system of claim 1, wherein when the fuel cell power generation module included in the first module group is started up and enters a power generating state, the control device uses the power generated by the fuel cell power generation module as startup power to start up at least one fuel cell power generation module included in the second module group. the first module group includes one fuel cell power generation module,
The power supply system of claim 2, wherein the control device uses power generated by the fuel cell power generation module included in the first module group as startup power to start up one or more of the fuel cell power generation modules included in the second module group. the first module group includes a plurality of fuel cell power generation modules;
When the plurality of fuel cell power generation modules included in the first module group are started up and enter a power generation state, the control device
start up one or more of the fuel cell power generation modules included in the second module group by using electric power generated by the plurality of fuel cell power generation modules included in the first module group as start-up electric power;
The power supply system according to claim 2 . Each of the plurality of fuel cell power generation modules further includes an auxiliary device that supplies fuel to the fuel cell;
5. The power supply system according to claim 1, wherein the power storage device in the fuel cell power generation module included in the first module group supplies startup power to at least the auxiliary machinery to start up the auxiliary machinery, and supplies fuel from the auxiliary machinery to the fuel cell. 5. The power supply system according to claim 1, wherein the power storage device comprises a storage battery having a capacity sufficient to cover the start-up power of one fuel cell power generation module. 5. The power supply system according to claim 1, wherein the emergency power storage device is capable of supplying startup power to the fuel cell power generation module to start up the fuel cell power generation module. a switch for selectively connecting the power storage device to any one of the plurality of fuel cell power generation modules;
the control device controls the switch based on operation availability information of the plurality of fuel cell power generation modules to select a fuel cell power generation module to which the power storage device is connected.
The power supply system according to any one of claims 2 to 4 .

Images