Fuel cell system

Abstract

This fuel cell system (100) is provided with: a fuel cell (10); a first input / output terminal (20) connected to a first external power source (50); a second input terminal (22) connected to a second external power source (52); a first input / output terminal (20) connected to an AC load; a second output terminal (24) connected to a DC load; and a control circuit (32) that executes an electrical process for converting DC power generated by the fuel cell (10) into AC power and supplying the AC power to the first input / output terminal (20) when the first input / output terminal (20) is connected to a first external power source (50), and for converting DC power generated by the fuel cell (10) into AC power and supplying the AC power to the second input / output terminal (22) when the second input terminal (22) is connected to a second external power source (52). The DC power generated by the fuel cell (10) is supplied to the second output terminal (24).

Description

Technical Field

[0001] The present disclosure relates to a fuel cell system. Background Art

[0002] The power generated by a fuel cell is DC power. Generally speaking, the DC power is converted into AC power and supplied to a load.

[0003] As described in Patent Documents 1 and 2, there is also known a system configured to store electric power generated by a fuel cell in a battery.

[0004] As described in Patent Document 3, the output of a fuel cell may be connected to an input terminal of a power plant of a solar power generation system.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-170420

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2007-242528

[0009] Patent Document 3: Japanese Patent Application Laid-Open No. 2020-137305 Summary of the Invention

[0010] Problems to be solved by the invention

[0011] Given the wide range of applications for fuel cell systems, it's useful for users to be able to select the type of power output. In this case, the fuel cell system is equipped with output terminals for outputting DC power and output terminals for outputting AC power. The DC power output terminal is connected to a DC load, while the AC power output terminal is connected to an AC load.

[0012] On the other hand, fuel cell systems, other than those equipped with batteries for autonomous operation, require an external power source for startup. Fuel cell systems that support multiple external power sources, such as single-phase AC power supplies and three-phase AC power supplies, are preferred because they offer increased versatility. However, fuel cell systems equipped with multiple input and output systems risk becoming cumbersome to set up. Furthermore, there is a concern about wiring errors.

[0013] In view of the above circumstances, an object of the present disclosure is to improve the ease of installation work in a fuel cell system that outputs both DC power and AC power to the outside.

[0014] Solutions for solving problems

[0015] The present disclosure provides a fuel cell system comprising:

[0016] fuel cells;

[0017] a first input terminal connected to a first external power source;

[0018] a second input terminal connected to a second external power source;

[0019] a first output terminal connected to an AC load;

[0020] a second output terminal connected to a DC load; and

[0021] a control circuit that performs electrical processing for converting the DC power generated by the fuel cell into AC power and supplying it to the first output terminal when the first input terminal is connected to the first external power supply, and supplying the DC power generated by the fuel cell to the second output terminal when the second input terminal is connected to the second external power supply.

[0022] Effects of the Invention

[0023] According to the technology disclosed herein, it is possible to improve the ease of installation work of the fuel cell system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic block diagram showing the configuration of a fuel cell system.

[0025] Figure 2 yes Figure 1 Detailed circuit diagram of a part of.

[0026] Figure 3 This is a flowchart of a process executed by the microcomputer of the control circuit to determine the type of power to be output. DETAILED DESCRIPTION

[0027] The following describes the embodiments in detail with reference to the accompanying drawings. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters or repeated descriptions of substantially the same structures may be omitted.

[0028] The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

[0029] (Implementation Method)

[0030] Next, use Figures 1 to 3 The following describes an embodiment.

[0031] [1-1. Structure]

[0032] Figure 1 1 is a schematic block diagram showing the structure of the fuel cell system 100 . Figure 2 yes Figure 1 A detailed circuit diagram of part of the Figure 1 As shown, the fuel cell system 100 includes a fuel cell 10, a first input / output terminal 20, a second input terminal 22, a second output terminal 24, and a control circuit 32. The fuel cell system 100 is configured to be able to output both DC power and AC power to the outside. When the first input / output terminal 20 is connected to the first external power source 50, AC power is output to the outside. When the second input terminal 22 is connected to the second external power source 52, DC power is output to the outside. Since the type of output power is automatically determined according to the external power source, no special settings or operations are required. As a result, the ease of setting up the fuel cell system 100 is improved.

[0033] The fuel cell 10 is an electrochemical device that generates electricity from hydrogen and oxidant gas. The form of the fuel cell 10 is not particularly limited. The fuel cell 10 is, for example, a solid polymer fuel cell, a solid oxide fuel cell, a phosphoric acid fuel cell, or a molten carbonate fuel cell.

[0034] The first input / output terminal 20 and the second input terminal 22 are terminals for connecting to an external power source for starting the fuel cell system 100. The first input / output terminal 20 is connected to the first external power source 50. In this case, AC power is output to the outside. The second input terminal is connected to the second external power source 52. In this case, DC power is output to the outside. The first input / output terminal 20 and the second input terminal 22 may also include a mechanical switch serving as a power switch.

[0035] The first external power supply 50 is, for example, an AC power supply. In this embodiment, the first input / output terminal 20 serves as both the first input terminal and the first output terminal. This configuration reduces the number of terminals. When AC power is directed back to the first external power supply 50, the first external power supply 50 can be treated as an AC load. The first external power supply 50 can be a three-phase AC power supply.

[0036] The second external power source 52 is, for example, an AC power source. However, the second external power source 52 is a different power source from the first external power source 50. In this embodiment, the second external power source 52 is a single-phase AC power source. For example, the voltage of the AC power from the first external power source 50, which is a three-phase AC power source, is 200 V (line voltage), while the voltage of the AC power from the second external power source 52, which is a single-phase AC power source, is also 200 V (line voltage). Here, "voltage" refers to the effective value.

[0037] The first external power supply 50 is, for example, a system power supply. The second external power supply 52 can be a system power supply or a power storage system capable of outputting AC power, such as a UPS (Uninterruptible Power Supply). The voltage of the second external power supply 52 can be equal to or different from the voltage of the first external power supply 50.

[0038] The second output terminal 24 is a terminal for connecting a DC load 54. The type of the DC load 54 is not particularly limited. The DC load 54 may also include a power conditioning system (PCS: Power Conditioning System). In this case, DC power of various voltages can be used. Depending on the power conditioning system, AC power with a voltage and / or frequency different from the voltage and / or frequency of the AC power output from the first input / output terminal 20 can also be used. That is, the fuel cell system 100 of this embodiment can be used directly in multiple countries where the voltage and / or frequency of commercial power sources are different.

[0039] The control circuit 32 is a circuit that performs predetermined electrical processing. The predetermined electrical processing includes a process for converting the DC power generated by the fuel cell 10 into AC power and supplying it to the first input / output terminal 20, and a process for supplying the DC power generated by the fuel cell 10 to the second output terminal 24. The former, i.e., the process for converting the DC power generated by the fuel cell 10 into AC power and supplying it to the first input / output terminal 20, is performed when the first input / output terminal 20 is connected to the first external power supply 50. The latter, i.e., the process for supplying the DC power generated by the fuel cell 10 to the second output terminal 24, is performed when the second input terminal 22 is connected to the second external power supply 52. ​​With such a configuration, special settings and operations when setting up the fuel cell system 100 can be omitted, thereby improving the ease of setting up the fuel cell system 100.

[0040] The control circuit 32 includes a microcomputer, memory, and input / output interfaces. The memory stores a control program for operating the fuel cell system 100. The microcomputer reads and executes the control program. The control circuit 32 may include multiple microcomputers or a programmable logic device such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array).

[0041] The fuel cell system 100 further includes a detection circuit 30. The detection circuit 30 detects the voltage at the first input / output terminal 20 and the voltage at the second input terminal 22 and outputs a detection signal. The detection signal is input to the control circuit 32. The control circuit 32 executes the aforementioned electrical processing based on the detection signal received from the detection circuit 30. With this configuration, the electrical processing appropriate to the type of power source connected to the fuel cell system 100 can be automatically executed.

[0042] Specifically, when a detection signal indicating that the first input / output terminal 20 is connected to the first external power source 50 is input to the control circuit 32, the control circuit 32 performs electrical processing for supplying AC power to the first input / output terminal 20. When a detection signal indicating that the second input terminal 22 is connected to the second external power source 52 is input to the control circuit 32, the control circuit 32 performs electrical processing for supplying DC power to the second output terminal 24.

[0043] In this embodiment, the detection circuit 30 includes a first detection circuit 30a and a second detection circuit 30b. The first detection circuit 30a is electrically connected to the first input / output terminal 20. The second detection circuit 30b is electrically connected to the second input terminal 22. Figure 2 As shown, the first detection circuit 30a detects the voltage between two lines (UV) selected from the three-phase AC wiring. The second detection circuit 30b detects the voltage between two lines (LN) of the single-phase AC wiring.

[0044] The fuel cell system 100 further includes a power supply circuit 34, a first relay 26, and a second relay 28. The power supply circuit 34 is supplied with AC power from a first external power supply 50 and a second external power supply 52. ​​The first relay 26 is located on the path from the first input / output terminal 20 to the power supply circuit 34. The second relay 28 is located on the path from the second input terminal 22 to the power supply circuit 34. The AC power from the first external power supply 50 or the second external power supply 52 is converted to DC power of a predetermined voltage and supplied to various locations in the fuel cell system 100.

[0045] like Figure 2As shown, the power supply circuit 34 includes, for example, an AC / DC converter 34a and a DC / DC converter 34b. The AC / DC converter 34a is electrically connected to the first input / output terminal 20 via the first relay 26, and is electrically connected to the second input terminal 22 via the second relay 28. In the AC / DC converter 34a, AC power is converted into DC power. The AC / DC converter 34a includes an insulating transformer, and the primary side is insulated from the secondary side. As a result, the high-voltage area for transmitting power is electrically separated from the low-voltage area for transmitting information. The DC power is stepped down in the DC / DC converter 34b and supplied to the control circuit 32. The power supply circuit 34 may also have multiple DC / DC converters. After the fuel cell 10 is started, DC power is supplied from the fuel cell 10 to the power supply circuit 34. After the DC power is adjusted to the required voltage in the power supply circuit 34, it is supplied to various parts of the fuel cell system 100.

[0046] The power supply circuit 34 can convert AC power within a certain voltage range (e.g., 180 V to 240 V) into DC power. With this configuration, even when the first external power supply 50 and the second external power supply 52 have different voltages, the power supply circuit 34 can be shared between the first external power supply 50 and the second external power supply 52. ​​Furthermore, the fuel cell system 100 can be easily used in multiple countries where the system power supply voltages vary.

[0047] The first relay 26 is arranged on the path from the first input / output terminal 20 to the power supply circuit 34. The second relay 28 is arranged on the path from the second input terminal 22 to the power supply circuit 34. When the first external power supply 50 is connected to the first input / output terminal 20, the detection circuit 30 switches the first relay 26 to conduction. When the second external power supply 52 is connected to the second input terminal 22, the detection circuit 30 switches the second relay to conduction. Specifically, the first detection circuit 30a switches the first relay 26 of the subsequent stage to conduction. The second detection circuit 30b switches the second relay 28 of the subsequent stage to conduction. With such a structure, special settings and operations when setting up the fuel cell system 100 can be omitted.

[0048] The detection circuit 30 can be configured to recognize the positive and negative voltages of the AC power as pulses and switch the first relay 26 or the second relay 28 to conduction. A voltage sensor 33 detects the voltage at any point along the path from the first relay 26 to the power supply circuit 34. Alternatively, if the input voltage is not within a specified range (e.g., 180V to 240V), the fuel cell system 100 is not activated, and an error is notified externally. This configuration can simplify the structure of the detection circuit 30.

[0049] Alternatively, the detection circuit 30 (first detection circuit 30a) may be configured to switch the first relay 26 on when a first external power source 50 having a predetermined voltage (e.g., 200±10V) is connected to the first input / output terminal 20. The detection circuit 30 (second detection circuit 30b) may be configured to switch the second relay 28 on when a second external power source 52 having a predetermined voltage (e.g., 200±10V) is connected to the second input terminal 22.

[0050] like Figure 2 As shown, in this embodiment, two of the three wires extending from the first input / output terminal 20 are connected to the two wires extending from the second input terminal 22, so that the power supply circuit 34 is shared between the first input / output terminal 20 and the second input terminal 22. With this circuit configuration, there is a risk of a short circuit between the first external power supply 50 and the second external power supply 52 when both the first input / output terminal 20 and the second input terminal 22 are connected to an external power source. To address this issue, in this embodiment, when the first input / output terminal 20 is connected to the first external power supply 50 and the second input terminal 22 is connected to the second external power supply 52, the detection circuit 30 maintains at least one of the first relay 26 and the second relay 28 open. This configuration prevents a short circuit between the first external power supply 50 and the second external power supply 52. ​​In other words, the fuel cell system 100 has a fail-safe function when both the first input / output terminal 20 and the second input terminal 22 are connected to an external power source. AC power is supplied to the power supply circuit 34 only from one of the first input / output terminal 20 and the second input terminal 22.

[0051] For example, large-scale facilities such as factories often use multiple power sources, including three-phase AC power sources and single-phase AC power sources. Therefore, the possibility of incorrectly connecting both the first input / output terminal 20 and the second input terminal 22 to the external power source cannot be ruled out. The fuel cell system 100 of this embodiment can prevent short circuits between power sources even if an incorrect wiring connection is made, making it particularly useful in facilities equipped with multiple power sources.

[0052] Furthermore, when the first input / output terminal 20 is connected to the first external power source 50 and the second input terminal 22 is connected to the second external power source 52, the detection circuit 30 outputs a detection signal indicating that both the first input / output terminal 20 and the second input terminal 22 are connected to the external power source. In this embodiment, the control circuit 32 receives the detection signal from the first detection circuit 30a and the detection signal from the second detection circuit 30b. Upon receiving these detection signals, the control circuit 32 notifies the outside world of a wiring connection error. This configuration also helps to facilitate the setup of the fuel cell system 100.

[0053] The means for notifying the outside of the wiring connection error is not particularly limited. The wiring connection error can be notified to the outside in the form of audio information and / or visual information.

[0054] Furthermore, when the first input / output terminal 20 is connected to the first external power source 50 and the second input terminal 22 is connected to the second external power source 52 , both power supply to the first input / output terminal 20 and power supply to the second output terminal 24 may be prohibited.

[0055] In addition, when the first input / output terminal 20 is connected to the first external power supply 50 and the second input terminal 22 is connected to the second external power supply 52, the first relay 26 is switched on and the second relay 28 is maintained off. Alternatively, the second relay 28 is switched on and the first relay 26 is maintained off. That is, there is a priority between the first relay 26 and the second relay 28. When the first relay 26 is switched on, the first relay 26 has priority. When the second relay 28 is switched on, the second relay 28 has priority. Such a structure also helps to improve the ease of setting up the fuel cell system 100.

[0056] like Figure 2 As shown, in this embodiment, the detection circuit 30 includes a logic circuit 30c and a logic circuit 30d for prioritizing the first relay 26 and the second relay 28. Logic circuit 30c is a NOT circuit. Logic circuit 30d is an AND circuit. The output of the second detection circuit 30b is input to the logic circuit 30c. The output of the first detection circuit 30a and the output of the logic circuit 30c are input to the logic circuit 30d.

[0057] When the second input terminal 22 is connected to the second external power supply 52, the second detection circuit 30b switches the second relay 28 to on and provides a High (H) signal to the logic circuit 30c. Then, the logic circuit 30c outputs Low (L) in reverse. When the second input terminal 22 is not connected to the second external power supply 52, the logic circuit 30c outputs High (H). When the first input-output terminal 20 is connected to the first external power supply 50, the first detection circuit 30a outputs High (H). When both inputs of the logic circuit 30d are High (H), the logic circuit 30d outputs High (H) to switch the first relay 26 to on. In other cases, the logic circuit 30d outputs Low (L) to maintain the first relay 26 off. That is, the first relay 26 is switched on only when the first detection circuit 30a is High (H) and the second detection circuit 30b is Low (L). According to Figure 2In the structure shown, the second input terminal 22 and the second relay 28 have a higher priority. Figure 2 The structure shown gives priority to the first input / output terminal 20 and the first relay 26 .

[0058] like Figure 2 As shown, the first relay 26 may include multiple relays provided on the three wires of the three-phase AC wiring. The second relay 28 may also include multiple relays provided on the two wires of the single-phase AC wiring. The first relay 26, the second relay 28, and the DC relay (direct current relay) 42 described later are, for example, mechanical relays or semiconductor relays. When the first external power supply 50 is the system power supply, the first relay 26 is a mechanical relay.

[0059] The fuel cell system 100 further includes a converter 38, an inverter 40, and a DC relay 42. The converter 38 can be a DC / DC converter that adjusts the voltage of the DC power generated by the fuel cell 10 to a required voltage (i.e., boosts the voltage). The DC relay 42 is arranged on a path from the converter 38 to the second output terminal 24. The DC power after voltage adjustment by the converter 38 is supplied to the second output terminal 24 via the DC relay 42. The inverter 40 converts the DC power generated by the fuel cell 10 into AC power. In this embodiment, the DC power output from the converter 38 is input to the inverter 40. The output terminal of the inverter 40 is connected to the first input / output terminal via the first relay 26.

[0060] When the DC relay 42 is disconnected, the DC power generated by the fuel cell 10 is supplied to the inverter 40. The DC power is converted to AC power in the inverter 40, so that the AC power flows back through the first input / output terminal 20 to the first external power source 50. Thus, the electrical processing performed by the control circuit 32 includes processing for controlling the inverter 40 and the DC relay 42. The control circuit 32 controls the inverter 40 and the DC relay 42 to selectively output AC power or DC power to the outside.

[0061] [1-2. Action]

[0062] Next, the operation of the fuel cell system 100 configured as described above will be described.

[0063] When the first input / output terminal 20 is connected to the first external power supply 50, the detection circuit 30 switches the first relay 26 to on. The second relay 28 is disconnected. Thus, three-phase AC power is supplied from the first external power supply 50 to the power supply circuit 34. When the second input terminal 22 is connected to the second external power supply 52, the detection circuit 30 switches the second relay 28 to on. The first relay 26 is disconnected. Thus, single-phase AC power is supplied from the second external power supply 52 to the power supply circuit 34. In the power supply circuit 34, DC power of the required voltage (for example, 24V, 12V, 5V) is generated and supplied to the control circuit 32, the auxiliary equipment of the fuel cell 10, and other places. The control circuit 32 performs control for operating the fuel cell 10. Thus, the fuel cell 10 is started. The auxiliary equipment of the fuel cell 10 includes equipment such as pumps, blowers, and valves. These devices are controlled by the control circuit 32.

[0064] Figure 3 This is a flowchart of the processing executed by the microcomputer of the control circuit 32 to determine the type of power to be output. Figure 3 Each process shown.

[0065] In step S1, a detection signal is obtained from the detection circuit 30. Specifically, a detection signal indicating that the first input / output terminal 20 is connected to the first external power supply 50 is obtained from the first detection circuit 30a, and a detection signal indicating that the second input terminal 22 is connected to the second external power supply 52 is obtained from the second detection circuit 30b.

[0066] In step S2 , based on the signal acquired from the detection circuit 30 , it is determined whether or not a predetermined voltage (for example, a three-phase AC voltage of 200 V) is input to the first input / output terminal 20 .

[0067] When a predetermined voltage is input to the first input / output terminal 20 , in step S3 , it is determined based on the signal obtained from the detection circuit 30 whether a predetermined voltage (eg, a single-phase AC voltage of 200 V) is input to the second input terminal 22 .

[0068] If the predetermined voltage is not input to the second input terminal 22 , the DC relay 42 is turned on in step S5 . This allows the DC power generated by the fuel cell 10 to be supplied to the DC load 54 via the DC relay 42 and the second output terminal 24 .

[0069] When voltage is input to both the first input / output terminal 20 and the second input terminal 22, a first error process is executed in step S4. The first error process is a process for externally notifying the user of an incorrect wiring connection. This external notification is performed, for example, in the form of an audio signal and / or a visual signal. The fuel cell system 100 may also include an audio device and / or a display device for externally notifying the user of the error.

[0070] If the specified voltage is not input to the first input / output terminal 20 , in step S6 , it is determined based on the signal obtained from the detection circuit 30 whether the specified voltage (eg, 200V single-phase AC voltage) is input to the second input terminal 22 .

[0071] When a predetermined voltage is input to the second input terminal 22, control of the inverter 40 is initiated in step S7. Specifically, control of the inverter 40 is initiated to convert the DC power generated by the fuel cell 10 into AC power. The AC power output from the inverter 40 is supplied to the first external power supply 50, serving as an AC load, via the first relay 26 and the first input / output terminal 20.

[0072] If no voltage is input to either the first input / output terminal 20 or the second input terminal 22, a second error process is executed in step S8. If no voltage is input to either the first input / output terminal 20 or the second input terminal 22 despite the control circuit 32 being activated, there is a high probability that some kind of fault has occurred. The second error process notifies the outside world of the occurrence of some kind of fault.

[0073] [1-3. Effects, etc.]

[0074] As described above, in this embodiment, the control circuit 32 performs electrical processing for converting the DC power generated by the fuel cell 10 into AC power and supplying it to the first output terminal when the first input terminal is connected to the first external power source 50, and for supplying the DC power generated by the fuel cell to the second output terminal when the second input terminal 22 is connected to the second external power source 52. This configuration eliminates the need for special settings and operations when installing the fuel cell system 100, thereby facilitating installation of the fuel cell system 100.

[0075] Furthermore, in this embodiment, the control circuit 32 can also notify the outside of a wiring connection error when the first input terminal is connected to the first external power source 50 and the second input terminal 22 is connected to the second external power source 52. This configuration helps to improve the ease of installation of the fuel cell system 100.

[0076] In this embodiment, the fuel cell system 100 may further include a detection circuit 30 that detects the voltage at the first input terminal and the voltage at the second input terminal 22 and outputs a detection signal. The control circuit 32 may also execute electrical processing based on the detection signal received from the detection circuit 30. With this configuration, electrical processing can be automatically executed according to the type of power supply connected to the fuel cell system 100.

[0077] In this embodiment, the fuel cell system 100 may further include: a detection circuit 30 that detects the voltage at the first input terminal and the voltage at the second input terminal 22; a power supply circuit 34 that supplies power from the first external power supply 50 and the second external power supply 52 to the power supply circuit 34; a first relay 26 disposed on the path from the first input terminal to the power supply circuit 34; and a second relay 28 disposed on the path from the second input terminal 22 to the power supply circuit 34. The detection circuit 30 may switch the first relay 26 on when the first input terminal is connected to the first external power supply 50, and switch the second relay 28 on when the second input terminal 22 is connected to the second external power supply 52. ​​This configuration eliminates the need for special settings and operations when installing the fuel cell system 100.

[0078] Furthermore, in this embodiment, when the first input terminal is connected to the first external power source 50 and the second input terminal 22 is connected to the second external power source 52, the detection circuit 30 may maintain at least one of the first relay 26 and the second relay 28 in an open state. This configuration prevents a short circuit between the first external power source 50 and the second external power source 52.

[0079] In this embodiment, the fuel cell system 100 may further include a converter 38 that adjusts the voltage of the DC power generated by the fuel cell 10; an inverter 40 that converts the DC power generated by the fuel cell 10 into AC power; and a DC relay 42 disposed on the path from the converter 38 to the second output terminal 24. The electrical processing may also include controlling the inverter 40 and the DC relay 42. The inverter 40 and the DC relay 42 are controlled by the control circuit 32 to selectively output AC power or DC power to the outside.

[0080] In the present embodiment, the first external power source 50 may be an AC power source, and the first input terminal may also serve as the first output terminal. This configuration can reduce the number of terminals.

[0081] Industrial applicability

[0082] The technology disclosed herein is useful for a fuel cell system capable of outputting both DC power and AC power to the outside.

[0083] Description of Reference Numerals

[0084] 10: Fuel cell; 20: First input / output terminal (first input terminal, first output terminal); 22: Second input terminal; 24: Second output terminal; 26: First relay; 28: Second relay; 30: Detection circuit; 30a: First detection circuit; 30b: Second detection circuit; 30c, 30d: Logic circuit; 32: Control circuit; 33: Voltage sensor; 34: Power supply circuit; 34a: AC / DC converter; 34b: DC / DC converter; 38: Converter; 40: Inverter; 42: DC relay; 50: First external power supply; 52: Second external power supply; 54: DC load; 100: Fuel cell system.

Claims

1. A fuel cell system comprising: fuel cells; a first input terminal connected to a first external power source; a second input terminal connected to a second external power source; A first output terminal connected to an AC load; a second output terminal connected to a DC load; as well as a control circuit that performs electrical processing for converting the DC power generated by the fuel cell into AC power and supplying it to the first output terminal when the first input terminal is connected to the first external power supply, and supplying the DC power generated by the fuel cell to the second output terminal when the second input terminal is connected to the second external power supply.

2. The fuel cell system according to claim 1, wherein: When the first input terminal is connected to the first external power supply and the second input terminal is connected to the second external power supply, the control circuit notifies the outside that there is an error in the wiring connection.

3. The fuel cell system according to claim 1, wherein: further comprising a detection circuit configured to detect the voltage of the first input terminal and the voltage of the second input terminal and output a detection signal, The control circuit performs the electrical processing according to the detection signal acquired from the detection circuit.

4. The fuel cell system according to claim 1, wherein: Also features: a detection circuit configured to detect a voltage at the first input terminal and a voltage at the second input terminal; a power supply circuit to which power is supplied from the first external power supply and the second external power supply; a first relay disposed on a path from the first input terminal to the power supply circuit; as well as a second relay disposed on a path from the second input terminal to the power supply circuit; When the first input terminal is connected to the first external power source, the detection circuit switches the first relay on; when the second input terminal is connected to the second external power source, the detection circuit switches the second relay on.

5. The fuel cell system according to claim 4, wherein: When the first input terminal is connected to the first external power source and the second input terminal is connected to the second external power source, the detection circuit maintains at least one selected from the first relay and the second relay in an OFF state.

6. The fuel cell system according to claim 1, wherein: Also features: a converter that adjusts the voltage of the DC power generated by the fuel cell; an inverter that converts the DC power generated by the fuel cell into the AC power; and a DC relay disposed on a path from the converter to the second output terminal, The electrical processing includes a process of controlling the inverter and the DC relay.

7. The fuel cell system according to claim 1, wherein: The first external power source is an AC power source, The first input terminal also serves as the first output terminal.

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