Power supply system and operation method thereof

Abstract

To prevent a malfunction resulting from erroneous detection of presence / absence of power supply from a commercial power supply.SOLUTION: A power supply system 100 of the present embodiment comprises: a plurality of power generation units each of which comprises a detection circuit 21 for detecting presence / absence of power supply from a commercial power supply 10 and capable of supplying power to a specific load 14; and a control device 30 communicably connected with each of the plurality of power generation unit, for permitting power supply to the specific load 14 from at least one of the plurality of power supply units only when a signal showing that there is no power supply from the commercial power supply 10 is acquired from all of the plurality of power supply units.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a power supply system and an operation method thereof.

Background Art

[0002] Power supply systems such as fuel cell systems may include a plurality of power generation units that can operate independently of each other in order to meet a wide range of customer needs or to flexibly cope with increases and decreases in load.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a power supply system as described above, the power supply destination may be different between a power outage and normal times. If a power outage of the commercial power supply is erroneously detected, there is a risk that the power of the power supply system will be supplied to an unexpected location. Therefore, such a power supply system requires a technique for preventing malfunction caused by erroneously detecting the presence or absence of power supply from the commercial power supply.

Means for Solving the Problems

[0005] The present disclosure provides a plurality of power generation units each having a detection circuit for detecting the presence or absence of power supply from a commercial power supply and capable of supplying power to a specific load, and a control device communicably connected to each of the plurality of power generation units and permitting power supply from at least one of the plurality of power generation units to the specific load only when signals indicating that there is no power supply from the commercial power supply are obtained from all of the plurality of power generation units. A power supply system comprising the above is provided.

[0006] In another aspect, the present disclosure relates to detecting the presence or absence of power supply from a commercial power source in each of a plurality of power generation units capable of supplying power to a specific load, transmitting a signal indicating the result of the detection from each of the plurality of power generation units to a control device, transmitting, from the control device to at least one of the plurality of power generation units, a signal permitting power supply to the specific load only when signals indicating the absence of power supply from the commercial power source are obtained from all of the plurality of power generation units, and provides an operation method of a power supply system including the above.

Advantages of the Invention

[0007] According to the technology of the present disclosure, malfunction due to erroneously detecting the presence or absence of power supply from a commercial power source can be prevented.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0009] (Knowledge etc. on which the present disclosure is based) Some power supply systems require an external power source. For example, a micro gas turbine system requires an external power source to drive a starting motor. A fuel cell system requires an external power source to drive auxiliary machines such as pumps, blowers, and valves at startup. Usually, a commercial power source is used as the external power source.

[0010] In consideration of the ease or safety of work during construction or maintenance, circuit breakers may be provided in each of the power lines branched from the commercial power supply to each power generation unit. When the circuit breaker is operated to electrically disconnect the power generation unit from the commercial power supply, the corresponding power generation unit detects the loss of the commercial power supply. However, the power generation unit cannot determine whether the commercial power supply has experienced a power outage or the circuit breaker has been turned off. If the power generation unit uniformly recognizes the loss of the commercial power supply without determining whether the commercial power supply has experienced a power outage or the circuit breaker has been turned off and permits the operation of the corresponding power generation unit, the following problems will occur. That is, if the operation of turning off the circuit breaker is a misoperation and it is not actually a power outage, there is a risk that power will be supplied to a specific load such as an emergency outlet. In this case, the risk of power being supplied to an unexpected location increases. Therefore, a technique for preventing malfunction due to misdetection of the presence or absence of power supply from the commercial power supply is required for the power supply system.

[0011] Hereinafter, embodiments will be described in detail with reference to the drawings. However, detailed descriptions that are more than necessary may be omitted. For example, detailed descriptions of well-known matters or duplicate descriptions of substantially the same configurations may be omitted.

[0012] The accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0013] (Embodiment 1) Hereinafter, Embodiment 1 will be described with reference to FIGS. 1 to 4.

[0014] [1-1. Configuration] FIG. 1 is a schematic configuration diagram of a power supply system 100 according to Embodiment 1. The power supply system 100 includes a plurality of power generation units 20 and a control device 30. The control device 30 is communicably connected to the plurality of power generation units 20.

[0015] A plurality of power generation units 20 can operate independently of each other. The power generation unit 20 requires an external power source at startup. In this embodiment, the plurality of power generation units 20 are connected to the commercial power source 10 via the power line 54. At startup, the power generation unit 20 uses the power of the commercial power source 10. After startup, the power generation unit 20 supplies the power required for operation with its own generated power. The commercial power source 10 is, for example, a three-phase AC power source.

[0016] In normal times when there is no power outage in the commercial power source 10, each of the power generation units 20 supplies power to the general load 12. The power output from the power generation unit 20 is, for example, single-phase AC power.

[0017] The plurality of power generation units 20 include a plurality of first power generation units 20a and a plurality of second power generation units 20b. A specific load 14 is connected to the first power generation unit 20a via a switch 15. The specific load 14 is not connected to the second power generation unit 20b.

[0018] The first power generation unit 20a is a power generation unit that performs self-sustained operation during a power outage of the commercial power source 10. That is, the first power generation unit 20a is a power generation unit capable of supplying power to the specific load 14. The second power generation unit 20b is a power generation unit that does not perform self-sustained operation during a power outage of the commercial power source 10. That is, the second power generation unit 20b is a power generation unit incapable of supplying power to the specific load 14. According to such a configuration, the output of the power supply system 100 can be made different between during a power outage and normal times. For example, a large output can be obtained during normal times, but the number of the first power generation units 20a and the number of the second power generation units 20b can be adjusted so that the output during a power outage is limited to the minimum necessary. That is, a power supply system 100 that meets the needs of consumers can be constructed.

[0019] However, all the power generation units 20 may be the first power generation units 20a. There is no limit to the number of the second power generation units 20b, which may be zero, one, or a plurality.

[0020] The specific load 14 is a load different from the general load 12. When there is a power outage in the commercial power supply 10, power can be supplied from the first power generation unit 20a to the specific load 14. Examples of the specific load 14 include emergency outlets. Normally, the power generated by the power generation unit 20 is supplied to the general load 12, but not to the specific load 14.

[0021] The switch 15 is connected to the commercial power supply 10 via the power line 54. When detecting a power outage in the commercial power supply 10, the switch 15 connects the first power generation unit 20a and the specific load 14 so that the power generated by the first power generation unit 20a is supplied to the specific load 14. The switch 15 may be configured such that the power of the commercial power supply 10 is not supplied to the specific load 14 during normal times, or may be configured such that the power of the commercial power supply 10 is supplied to the specific load 14 during normal times.

[0022] FIG. 2 is a schematic configuration diagram of the power generation unit 20. Each of the plurality of power generation units 20 includes a detection circuit 21, a control device 22, and a main body unit 23. The detection circuit 21 is a circuit that detects the presence or absence of power supply from the commercial power supply 10. Examples of the detection circuit 21 include a voltage detection circuit, a current detection circuit, and a zero-cross detection circuit. The zero-cross detection circuit is a circuit that generates a pulse signal synchronized with the timing when the AC voltage crosses the zero voltage. The control device 22 recognizes the presence or absence of power supply from the commercial power supply 10 based on the pulse signal. When there is a power supply from the commercial power supply 10, the pulse signal is input to the control device 22. When there is no power supply from the commercial power supply 10, the pulse signal is not input to the control device 22.

[0023] The control device 22 is constituted by a microcomputer and executes control necessary for power generation by the main body unit 23. The control device 22 also communicates with the control device 30 of the power supply system 100 using a protocol such as TCP / IP.

[0024] The main body 23 is, for example, a fuel cell. That is, the power generation unit 20 can be a fuel cell unit. Since a fuel cell requires external power to operate auxiliary devices at startup, it is suitable for the power supply system 100 of the present embodiment. The type of fuel cell is not particularly limited, and examples include a polymer electrolyte fuel cell, a solid oxide fuel cell, a phosphoric acid fuel cell, and a molten carbonate fuel cell. The polymer electrolyte fuel cell is suitable for the power supply system 100 of the present embodiment because the time required to reach the rated output from startup is shorter than that of other fuel cells and it is suitable for frequent operation and stop.

[0025] As another example of the main body 23, a micro gas turbine or the like can be mentioned.

[0026] As shown in FIG. 1, the control device 30 is a control device superior to a plurality of power generation units 20, communicates with the control device 22 of the power generation unit 20, and controls the operation and stop of the power generation unit 20. The control device 30 is composed of a computer such as a server computer or a workstation.

[0027] The power supply system 100 further includes a UPS 40 (uninterruptible power supply) and a UPS 42. The UPS 40 and the UPS 42 are connected to the commercial power supply 10a via a power line 45. The commercial power supply 10a is, for example, a single-phase AC power supply. Any one phase of the three-phase AC power supply 10 can be used as the commercial power supply 10a. The UPS 40 and the UPS 42 detect the presence or absence of power supply from the commercial power supply 10a and determine power failure and non-power failure.

[0028] In this specification, a power failure of the commercial power supply 10 means a power failure of the commercial power supply 10a. Similarly, a power failure of the commercial power supply 10a means a power failure of the commercial power supply 10.

[0029] The UPS 40 supplies power to at least one of the plurality of power generation units 20 in the event of a power outage of the commercial power supply 10a. In the present embodiment, the UPS 40 is connected to each of the first power generation units 20a via the power line 46. In the event of a power outage of the commercial power supply 10a, power is supplied from the UPS 40 to the first power generation unit 20a. Even if the first power generation unit 20a is in a stopped state during a power outage of the commercial power supply 10a, the first power generation unit 20a can be started using the power of the UPS 40.

[0030] The UPS 42 supplies power to the control device 30 in the event of a power outage of the commercial power supply 10a. Normally, power is supplied from the commercial power supply 10a to the control device 30 via the UPS 42.

[0031] In the present embodiment, the UPS 40 and the UPS 42 may be constituted by a single UPS.

[0032] The commercial power supply 10a is connected to each of the power generation units 20. The first power generation unit 20a is connected to the commercial power supply 10a via the power line 45, the UPS 40, and the power line 46. The second power generation unit 20b is connected to the commercial power supply 10a via the power line 45. There is no UPS on the path from the commercial power supply 10a to the second power generation unit 20b. Both the commercial power supply 10 and the commercial power supply 10a are connected to each of the plurality of power generation units 20. Single-phase AC power can be supplied from the commercial power supply 10a to the auxiliary machines of the power generation unit 20. However, since the commercial power supply 10a is connected to the first power generation unit 20a via the UPS 40, the first power generation unit 20a cannot directly detect a power outage of the commercial power supply 10a. The power outage of the commercial power supply 10a is detected in any one of the phases of the commercial power supply 10, which is a three-phase AC power supply connected to the first power generation unit 20a separately from the commercial power supply 10a (Figure 2).

[0033] Since the commercial power supply 10a is directly connected to the second power generation unit 20b, the second power generation unit 20b can directly detect a power outage of the commercial power supply 10a. However, in the present embodiment, even in the second power generation unit 20b, a power outage is detected on the three-phase AC side in the same manner as in the first power generation unit 20a. As a result, the specifications (wiring) of the first power generation unit 20a and the specifications (wiring) of the second power generation unit 20b can be made common. The first power generation unit 20a and the second power generation unit 20b can be freely combined to increase the design freedom of the power supply system 100 while reducing costs. Since the commercial power supplies 10 and 10a may be connected to the first power generation unit 20a and the second power generation unit 20b in the same manner, wiring errors during construction are also less likely to occur.

[0034] The power lines 45 and 46 are power lines that connect the commercial power supply 10a and a plurality of first power generation units 20a via the UPS 40. The power line 54 is a power line that connects the commercial power supply 10 and the first power generation unit 20a without passing through the UPS. According to such a configuration, power can be supplied from the UPS 40 to the first power generation unit 20a during a power outage of the commercial power supplies 10 and 10a, and a power outage of the commercial power supply 10 can be detected based on the presence or absence of power supply by the power line 54 that does not pass through the UPS.

[0035] Circuit breakers 50 and 52 are provided in the power supply path from the commercial power supply 10 to the power generation unit 20. The circuit breaker 50 is provided corresponding to each of the power generation units 20 and is provided at a position where any power generation unit 20 can be electrically disconnected from the commercial power supply 10. The circuit breaker 52 is provided at a position upstream of the circuit breaker 50 and is configured to be able to electrically disconnect all of the plurality of power generation units 20 from the commercial power supply 10 at once.

[0036] In the power supply path from the commercial power supply 10a to the power generation unit 20, a circuit breaker 51 and a circuit breaker 53 are provided. The circuit breaker 51 is provided corresponding to each of the power generation units 20, and is provided at a position where any power generation unit 20 can be electrically disconnected from the commercial power supply 10a (and the UPS). The circuit breaker 53 is provided at a position upstream of the circuit breaker 51, and is configured to be able to electrically disconnect all of the plurality of power generation units 20 from the commercial power supply 10a (and the UPS) collectively.

[0037] The circuit breakers 50, 51, 52, and 53 may be housed in a common distribution board. The positions of the circuit breakers 50, 51, 52, and 53 can be changed as appropriate. The circuit breakers 50, 51, 52, and 53 can be omitted as appropriate.

[0038] [1-2. Operation] Regarding the power supply system 100 configured as described above, its operation will be described below.

[0039] (Normal time) A start instruction is given from the control device 30 to each power generation unit 20. In response to acquiring the start instruction, the power generation unit 20 drives auxiliary equipment, a start motor, etc. using the power of the commercial power supply 10a. The power generated by the power generation unit 20 is supplied to the general load 12.

[0040] (During a power outage: the first power generation unit 20a) If a power outage occurs in the commercial power supply 10 during the operation of the first power generation unit 20a, the first power generation unit 20a continues to operate as it is. The switch 15 is switched so that the power generated by the first power generation unit 20a is supplied to the specific load 14. Specifically, if the specific load 14 is used only during a power outage, the switch 15 is switched on. If the specific load 14 is used during normal times and during a power outage, the switch 15 is switched so that the power supply source to the specific load 14 moves from the commercial power supply 10 to the first power generation unit 20a. Note that when a power outage occurs, all of the first power generation units 20a in operation may be stopped once.

[0041] FIG. 3 is a flowchart showing a power failure detection process executed in the control device 30. The power failure detection process shown in FIG. 3 is executed at a predetermined cycle (for example, every minute) while the first power generation unit 20a is stopped. However, it may also be performed while the first power generation unit 20a is operating.

[0042] In step S1, the control device 30 acquires signals indicating the state of the commercial power supply 10 from each of the first power generation units 20a.

[0043] Even if the commercial power supply 10 fails while the first power generation unit 20a is stopped, power is supplied from the UPS 40 to the detection circuit 21 and the control device 22 of the first power generation unit 20a. Power is supplied to the control device 30 from the UPS 42. Therefore, even if the commercial power supply 10 fails, communication between the control device 22 of the first power generation unit 20a and the control device 30 is possible. Communication between the control device 22 of the first power generation unit 20a and the control device 30 is periodically performed at a predetermined cycle (for example, a cycle of one minute). Through this communication, the control device 22 sequentially notifies the control device 30 of the presence or absence of power supply from the commercial power supply 10 and the state of the first power generation unit 20a. The state of the first power generation unit 20a includes that the first power generation unit 20a is operating, that the first power generation unit 20a is stopped, the generated power of the first power generation unit 20a, and the like. Not only the first power generation unit 20a but also the state of the second power generation unit 20b may be sequentially notified to the control device 30.

[0044] In step S2, it is determined whether power failure signals have been acquired from all of the first power generation units 20a. That is, it is determined whether the commercial power supply 10 has failed. The power failure signal is a signal indicating the absence of power supply from the commercial power supply 10. When this signal is acquired from all of the plurality of first power generation units 20a, it is determined that the commercial power supply 10 has failed.

[0045] When the control device 30 obtains a power failure signal from all of the first power generation units 20a, it permits power supply to the specific load 14 from at least one of the plurality of first power generation units 20a. In the present embodiment, power supply to the specific load 14 is permitted from all of the first power generation units 20a. According to such a configuration, malfunction due to erroneously detecting the presence or absence of power supply from the commercial power supply 10 can be prevented.

[0046] In step S3, a signal permitting power supply to the specific load 14 is transmitted to each of the plurality of first power generation units 20a. In response to obtaining this signal, the control device 22 of the first power generation unit 20a recognizes that the commercial power supply 10 has truly failed. Thereby, the power generated by the first power generation unit 20a can be output to the specific load 14 via the switch 15.

[0047] In step S4, a start instruction is transmitted to the plurality of first power generation units 20a. In response to obtaining the start instruction, the plurality of first power generation units 20a start with the power of the UPS 40. The UPS 40 enables the first power generation units 20a to start even when the commercial power supply 10 fails. The power generated by the first power generation unit 20a is supplied to the specific load 14.

[0048] Note that the control device 30 may transmit a startup instruction dedicated for power outage to the first power generation unit 20a in all control cycles during both power outage and non-power outage periods. When detecting a power outage of the commercial power supply 10, the first power generation unit 20a may start (or continue operation) according to the startup instruction dedicated for power outage, and when detecting the restoration of the commercial power supply 10, the first power generation unit 20a may start (or continue operation) according to the startup instruction dedicated for non-power outage. In this case, when the commercial power supply 10 experiences a power outage, regardless of the determination result in step S2, the first power generation unit 20a can start immediately according to the startup instruction dedicated for power outage. However, even if power generation actually starts in the first power generation unit 20a, power supply from the first power generation unit 20a to the specific load 14 is not permitted and is not performed unless the signal in step S3 is received. If such a state continues for a predetermined time (10 minutes in step S6 described later), the operation of the first power generation unit 20a may be stopped. According to such a configuration, the waiting time from the occurrence of the power outage until power is supplied to the specific load 14 can be reduced.

[0049] According to the above processing, step S4 is omitted. That is, the first power generation unit 20a starts (or continues operation) in response to detecting a power outage of the commercial power supply 10 and transmits a power outage signal to the control device 30. The control device 30 performs the processing from step S1 to step S3 and from step S5 to step S8.

[0050] In step S4, a start instruction may be transmitted one by one in sequence to a plurality of first power generation units 20a. That is, the control device 30 starts the plurality of first power generation units 20a one by one using the power of the UPS 40. For example, the control device 30 transmits a start instruction to the first power generation unit 20a to which the smallest address is assigned. The first power generation unit 20a to which the smallest address is assigned starts using the power of the UPS 40, and when it reaches the rated output, it supplies its generated power to the auxiliary equipment and notifies the control device 30 that it has reached the rated output. When the control device 30 acquires a signal indicating that the first power generation unit 20a to which the smallest address is assigned has reached the rated output, the control device 30 transmits a start instruction to the first power generation unit 20a to which the next address is assigned. The control device 30 repeats the same process until the first power generation unit 20a to which the last address is assigned reaches the rated output. Therefore, the plurality of first power generation units 20a start one by one in the order of the addresses. With such a configuration, a large capacity is not required for the UPS 40, so the cost of the UPS 40 can be reduced.

[0051] FIG. 4 is a diagram showing the flow of power when the commercial power supply 10 fails. The thick line indicates the flow of power. When the commercial power supply 10 (and the commercial power supply 10a) fails, power is supplied from the UPS 42 to the control device 30. Power is supplied from the UPS 40 to each of the first power generation units 20a. The power generated by the first power generation unit 20a is supplied to the corresponding specific load 14 via the switch 15.

[0052] In step S2, if a power failure signal is not obtained from all of the first power generation units 20a, in step S5, it is determined whether a power failure signal is obtained from any of the first power generation units 20a. If a power failure signal is obtained from any of the first power generation units 20a, in step S6, it is determined whether 10 minutes have elapsed since the acquisition of the power failure signal. If 10 minutes have elapsed, in step S7, a stop instruction is transmitted. According to such a configuration, it is possible to avoid unnecessarily consuming energy in a state where the power generated by the first power generation unit 20a is not output to the specific load 14 continuously.

[0053] Also, when a power failure signal is obtained from any of the first power generation units 20a, a timer that measures a predetermined time of about 10 minutes is started. For example, the timer is started at the same timing as the acquisition of the power failure signal in step S1. The timer is a software timer that the control device 30 has. If a power failure signal cannot be obtained from all of the first fuel cell units 20a while the predetermined time measured by the timer elapses, the control device 30 determines that there is no power failure in the commercial power supplies 10 and 10a, and performs subsequent electrical processing. Specifically, in step S8, a signal for prohibiting output to the specific load is transmitted to each of the plurality of first power generation units 20a, or the control device 30 waits without transmitting a signal for permitting output to the specific load. According to such processing, it is possible to more reliably prevent malfunction caused by erroneously detecting the presence or absence of power supply from the commercial power supply 10.

[0054] For example, although the signal obtained from a specific first power generation unit 20a indicates a power outage of the commercial power supply 10, but the signals obtained from the remaining first power generation units 20a indicate no power outage of the commercial power supply 10, it is predicted that the circuit breaker 50 corresponding to the specific first power generation unit 20a has been operated to turn off. In this case, the control device 30 does not permit power supply to the specific load 14 and does not start the first power generation unit 20a. Even if the circuit breaker 50 is operated erroneously, power is not supplied to the specific load 14. That is, according to the present embodiment, it is possible to prevent malfunction due to erroneously detecting the presence or absence of power supply from the commercial power supply 10. According to the present embodiment, it is possible to avoid power being supplied to an unexpected location.

[0055] Also, even if a power outage actually occurs, a power outage signal may not be transmitted from all the first fuel cell units 20a to the control device 30 in the same communication cycle, and there may be some deviation in the timing of acquiring the power outage signal. According to the present embodiment, even if there is some deviation in the timing of acquiring the power outage signal, it is possible to correctly execute subsequent electrical processes (steps S3, S4).

[0056] In addition, even when no power outage signal is acquired from any of the first power generation units 20a, in step S8, a signal for prohibiting output to the specific load may be transmitted to the first power generation unit 20a.

[0057] During the operation of the first power generation unit 20a, it is possible to determine the power outage / no power outage of the commercial power supplies 10 and 10a according to the flowchart shown in FIG. 3. When the first fuel cell unit 20a is in operation, if a power outage signal is acquired only from a specific first fuel cell unit 20a, in step S8, a stop signal may be transmitted to the specific first fuel cell unit 20a. Thereby, it is possible to stop the operation of the first fuel cell unit 20a suspected of erroneously detecting the presence or absence of power supply from the commercial power supply 10.

[0058] (During power outage: second power generation unit 20b) If a power outage occurs in the commercial power supply 10 during the operation of the second power generation unit 20b, the second power generation unit 20a continues to operate as it is. Alternatively, when a power outage occurs, the second power generation unit 20b in operation may be stopped.

[0059] If a power outage occurs in the commercial power supply 10 while the second power generation unit 20b is stopped, the second power generation unit 20b cannot start and thus continues to be in a stopped state.

[0060] When the commercial power supply 10 is restored, the second power generation unit 20b resumes operation in accordance with an instruction from the control device 30.

[0061] [1-3. Effects, etc.] As described above, in the present embodiment, the control device 30 permits power supply from at least one of the plurality of first power generation units 20a to the specific load 14 only when signals indicating the absence of power supply from the commercial power supply 10 are obtained from all of the plurality of first power generation units 20a. According to such a configuration, malfunction due to erroneously detecting the presence or absence of power supply from the commercial power supply 10 can be prevented.

[0062] Further, in the present embodiment, the power supply system 100 may further include a UPS 40 that supplies power to at least one of the plurality of first power generation units 20a during a power outage of the commercial power supply 10. At least one of the plurality of first power generation units 20a may be started with the power of the UPS 40. The UPS 40 enables the first power generation unit 20a to start even during a power outage of the commercial power supply 10.

[0063] Further, in the present embodiment, the control device 30 may start the plurality of first power generation units 20a one by one with the power of the UPS 40. According to such a configuration, a large capacity is not required for the UPS 40, so the cost of the UPS 40 can be reduced.

[0064] Also, in the present embodiment, the power supply system 100 may further include a power line 46 that connects the commercial power supply 10a and a plurality of first power generation units 20a via the UPS 40, and a power line 54 that connects the commercial power supply 10 and a plurality of first power generation units 20a without passing through the UPS 40. According to such a configuration, power can be supplied from the UPS 40 to the first power generation unit 20a during a power outage of the commercial power supplies 10 and 10a, and the power outage of the commercial power supply 10 can be detected based on the presence or absence of power supply by the power line 54 that does not pass through the UPS.

[0065] Also, in the present embodiment, the power generation unit 20 may be a fuel cell unit. Since a fuel cell requires external power to operate auxiliary devices at startup, it is suitable for the power supply system 100 of the present embodiment.

Industrial Applicability

[0066] The technology of the present disclosure is useful for a power supply system. In particular, the technology of the present disclosure is useful for a power supply system as a distributed power source system.

Description of Reference Numerals

[0067] 10, 10a Commercial power supply 12 General load 14 Specific load 15 Switch 20 Power generation unit 20a First power generation unit 20b Second power generation unit 21 Detection circuit 22 Control device 23 Main body part 30 Control device 40, 42 UPS 45, 46, 54 Power line 50, 51, 52, 53 Circuit breaker 100 Power supply system

Claims

1. A plurality of power generation units each having a detection circuit for detecting the presence or absence of power supply from a commercial power source and capable of supplying power to a specific load, and a control device communicably connected to each of the plurality of power generation units, and permitting power supply from at least one of the plurality of power generation units to the specific load only when signals indicating the absence of power supply from the commercial power source are obtained from all of the plurality of power generation units, A power supply system comprising:

2. The power supply system according to claim 1, further comprising an uninterruptible power supply device for supplying power to at least one of the plurality of power generation units during a power outage of the commercial power source, wherein at least one of the plurality of power generation units is started with the power of the uninterruptible power supply device. The power supply system according to claim 1.

3. The control device starts the plurality of power generation units one by one with the power of the uninterruptible power supply device. The power supply system according to claim 2.

4. A power line connecting the commercial power source and the plurality of power generation units via the uninterruptible power supply device, and a power line connecting the commercial power source and the plurality of power generation units without passing through the uninterruptible power supply device, The power supply system according to any one of claims 1 to 3, further comprising:

5. The power supply system according to claim 1, wherein the power generation unit is a fuel cell unit. The power supply system according to claim 1.

6. Detecting the presence or absence of power supply from a commercial power source in each of a plurality of power generation units capable of supplying power to a specific load; transmitting a signal indicating the result of the detection from each of the plurality of power generation units to a control device; and transmitting, from the control device, a signal permitting power supply to the specific load to at least one of the plurality of power generation units only when the signals indicating the absence of power supply from the commercial power source are obtained from all of the plurality of power generation units. An operation method of a power supply system, comprising:

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