JP2019145374A - Fuel cell power generation system - Google Patents

Abstract

To realize a configuration advantageous in cost by enabling a function for breaking both breaker relay parts in the case of electric leakage occurrence and a function for another fuel cell power generation system to coexist.SOLUTION: During a period in which a third ON condition that an ON signal is inputted to input parts 163L and 163R is fulfilled, a two-input AND circuit 163 transmits a voltage supply detection signal to a control device 180. It is a condition required for the control device 180 to permit voltage supply from a fuel cell unit 150 to a second connection passage 142 that first to third output conditions are fulfilled. The first output condition is a condition that an ON signal is inputted to an operation input part 162M. The second output condition is a condition that a fuel cell power generation system 200 does not detect first abnormality. The third output condition is a condition that the control device 180 receives the voltage supply detection signal.SELECTED DRAWING: Figure 7

Description

  The present disclosure relates to a fuel cell power generation system.

  There is known a system that includes two connection paths, each connection path has a cutoff relay unit, and shuts off both cutoff relay units when a leakage occurs. An example of such a system is described in US Pat. Specifically, the system of Patent Document 1 includes a first connection path used to guide power from the nighttime power source to the first heater, and a second connection path used to guide power from the daytime power source to the second heater. And. Each of these connection paths has a cutoff relay section.

Japanese Utility Model Publication No. 58-127824

  In patent document 1, it is not examined to apply the above system to a fuel cell power generation system. The present disclosure has studied a configuration that can coexist the function of shutting off both shut-off relay sections when a leakage occurs and the function for other fuel cell power generation systems, and is advantageous in terms of cost.

This disclosure
A fuel cell power generation system connected to a first system power source using a first connection path and connected to a second system power source using a second connection path,
A first interrupting relay section provided on the first connection path;
A second cutoff relay provided on the second connection path;
A fuel cell unit connected to the first system power supply using the first connection path and connected to the second system power supply using the second connection path;
The first interrupting relay has a three-input section, that is, an earth leakage input section, an abnormal input section, and an operation input section, and the first on-state relay is satisfied in a period in which a first on-condition that an on signal is inputted to these three input sections is satisfied. A first three-input AND circuit that maintains the first interrupting relay unit in an off state during a period when the first on condition is not satisfied,
The second interrupting relay has a three-input section including an earth leakage input section, an abnormal input section, and an operation input section, and the second on-state relay is in a period in which a second on-condition is established that an on signal is input to the three input sections. A second three-input AND circuit that maintains the second cut-off relay unit in an off state during a period when the second on-condition is not satisfied,
A first ON operation for obtaining a state in which an ON signal is input to the operation input unit of the first three-input AND circuit, and an ON signal is input to the operation input unit of the first three-input AND circuit A first off operation for obtaining a non-existing state, a second on operation for obtaining a state in which an on signal is input to the operation input section of the second three-input AND circuit, and the second three-input AND A second off operation for obtaining a state in which no on signal is input to the operation input unit of the circuit;
A control device for recognizing an operation received by the operation unit and occurrence of a predetermined first abnormality;
The control device is configured to provide a voltage supply detection signal in a period in which a third on-condition is established in which an on-signal is input to the two input units, the earth leakage input unit and the power recovery input unit. And a two-input AND circuit that does not transmit the voltage supply detection signal to the control device in a period in which the third ON condition is not satisfied,
When the fuel cell power generation system detects a leakage, an ON signal to the leakage input section of the first three-input AND circuit, the leakage input section of the second three-input AND circuit, and the leakage input section of the two-input AND circuit Is stopped,
When the fuel cell power generation system detects the first abnormality, the control device inputs an ON signal to the abnormality input unit of the first three-input AND circuit and the abnormality input unit of the second three-input AND circuit. Is stopped,
When the fuel cell power generation system detects voltage supply from the second power supply to the second connection path, an ON signal is input to the power recovery input unit of the two-input AND circuit,
The fact that the first output condition, the second output condition, and the third output condition are satisfied is a necessary condition for the control device to permit power supply from the fuel cell unit to the second connection path,
The first output condition is a condition that an ON signal is input to the operation input unit of the second three-input AND circuit,
The second output condition is a condition that the fuel cell power generation system does not detect the first abnormality,
The third output condition provides a fuel cell power generation system, which is a condition that the control device receives the voltage supply detection signal.

  The fuel cell power generation system according to the present disclosure has a function of cutting off the first and second cutoff relay units when a leakage occurs. The fuel cell power generation system further has another function for the fuel cell power generation system that shuts off these relay sections when a predetermined abnormality occurs and when an external operation is performed by a person. Moreover, the fuel cell power generation system according to the present disclosure is advantageous from the viewpoint of cost reduction.

FIG. 1 is a circuit diagram of a fuel cell power generation system according to an embodiment. FIG. 2 is a diagram for explaining the operation of the fuel cell power generation system of FIG. FIG. 3 is a diagram for explaining the operation of the fuel cell power generation system of FIG. FIG. 4 is a diagram for explaining the operation of the fuel cell power generation system of FIG. FIG. 5 is a diagram for explaining the operation of the fuel cell power generation system of FIG. FIG. 6 is a circuit diagram showing a part of the fuel cell power generation system of FIG. 1 in detail. FIG. 7 is a circuit diagram for explaining the switching device according to the embodiment.

(Knowledge that became the basis of this disclosure)
Patent Document 1 discloses a system that includes two connection paths, each connection path includes a cutoff relay unit, and shuts off both cutoff relay units when a leakage occurs. However, Patent Document 1 does not consider applying the system to a fuel cell power generation system. If a fuel cell power generation system in which the first system power source and the fuel cell unit are connected using the first connection path and the second system power source and the fuel cell unit are connected using the second connection path is configured, Power can be supplied from the power source to the fuel cell unit. If such a system is configured, the power generated by the fuel cell unit can be supplied to the system power supply.

  In the fuel cell power generation system, in addition to the occurrence of electric leakage, the interruption relay part of the first connection path and the interruption relay part of the second connection path are interrupted both when a predetermined abnormality such as an overcurrent occurs and when an external operation is performed by a person. It is possible to make it. Providing the breaker relay with other functions in addition to the function of the earth leakage breaker contributes to the cost reduction of the system.

  Further, in the fuel cell power generation system, it is conceivable that supply of power generated by the fuel cell unit to the second connection path is started when voltage is supplied from the second power supply to the fuel cell unit. It is possible to configure the fuel cell power generation system so that it can be detected whether or not voltage is supplied from the second power supply to the second connection path. However, in consideration of the possibility that the second cutoff relay section is cut off, the fact that the voltage is supplied from the second system power source to the second connection path means that the voltage is supplied from the second system power source to the fuel cell unit. Does not mean immediately.

  Therefore, the present disclosure multi-functions the interrupting relay unit as described above, and when the voltage is supplied from the second power supply to the fuel cell unit, the generated power of the fuel cell unit is supplied to the second connection path. The purpose is to provide a technology suitable for starting supply.

(Outline of one aspect according to the present disclosure)
The fuel cell power generation system according to the first aspect of the present disclosure includes:
A fuel cell power generation system connected to a first system power source using a first connection path and connected to a second system power source using a second connection path,
A first interrupting relay section provided on the first connection path;
A second cutoff relay provided on the second connection path;
A fuel cell unit connected to the first system power supply using the first connection path and connected to the second system power supply using the second connection path;
The first interrupting relay has a three-input section, that is, an earth leakage input section, an abnormal input section, and an operation input section, and the first on-state relay is satisfied in a period in which a first on-condition that an on signal is inputted to these three input sections is satisfied. A first three-input AND circuit that maintains the first interrupting relay unit in an off state during a period when the first on condition is not satisfied,
The second interrupting relay has a three-input section including an earth leakage input section, an abnormal input section, and an operation input section, and the second on-state relay is in a period in which a second on-condition is established that an on signal is input to the three input sections. A second three-input AND circuit that maintains the second cut-off relay unit in an off state during a period when the second on-condition is not satisfied,
A first ON operation for obtaining a state in which an ON signal is input to the operation input unit of the first three-input AND circuit, and an ON signal is input to the operation input unit of the first three-input AND circuit A first off operation for obtaining a non-existing state, a second on operation for obtaining a state in which an on signal is input to the operation input section of the second three-input AND circuit, and the second three-input AND A second off operation for obtaining a state in which no on signal is input to the operation input unit of the circuit;
A control device for recognizing an operation received by the operation unit and occurrence of a predetermined first abnormality;
The control device is configured to provide a voltage supply detection signal in a period in which a third on-condition is established in which an on-signal is input to the two input units, the earth leakage input unit and the power recovery input unit. And a two-input AND circuit that does not transmit the voltage supply detection signal to the control device in a period in which the third ON condition is not satisfied,
When the fuel cell power generation system detects a leakage, an ON signal to the leakage input section of the first three-input AND circuit, the leakage input section of the second three-input AND circuit, and the leakage input section of the two-input AND circuit Is stopped,
When the fuel cell power generation system detects the first abnormality, the control device inputs an ON signal to the abnormality input unit of the first three-input AND circuit and the abnormality input unit of the second three-input AND circuit. Is stopped,
When the fuel cell power generation system detects voltage supply from the second power supply to the second connection path, an ON signal is input to the power recovery input unit of the two-input AND circuit,
The fact that the first output condition, the second output condition, and the third output condition are satisfied is a necessary condition for the control device to permit power supply from the fuel cell unit to the second connection path,
The first output condition is a condition that an ON signal is input to the operation input unit of the second three-input AND circuit,
The second output condition is a condition that the fuel cell power generation system does not detect the first abnormality,
The fuel cell power generation system, wherein the third output condition is a condition that the control device receives the voltage supply detection signal.

  According to the first aspect, a multifunctional cutoff relay unit is realized. Specifically, the first interrupting relay unit and the second interrupting relay unit can be interrupted when an electric leakage occurs. With the contribution of the control device, these relay units can be shut off when the first abnormality occurs. Due to the contribution of the operation unit, these interruption relay units can be interrupted during external operation by a person. The first mode is suitable for starting supply of the generated power of the fuel cell unit to the second connection path when voltage is supplied from the second power supply to the fuel cell unit.

  In the second aspect of the present disclosure, for example, in the fuel cell power generation system according to the first aspect, the first system power source and the second system power source are power sources using a commercial power source as a power supply source, and the first abnormality Is an overcurrent in the fuel cell power generation system or an abnormality in the voltage of the commercial power supply.

  According to the 2nd aspect, when the overcurrent in a fuel cell power generation system or the abnormality of the voltage of a commercial power source generate | occur | produces, a 1st interruption | blocking relay part and a 2nd interruption | blocking relay part can be interrupted | blocked.

  In the third aspect of the present disclosure, for example, in the fuel cell power generation system according to the first aspect or the second aspect, the fuel cell unit further includes a DCAC inverter, and the DCAC inverter is separated from the fuel cell unit. When power is supplied to the connection path, power conversion is performed to convert DC power generated by the fuel cell unit into AC power, and the first output condition, the second output condition, and the third output condition are satisfied. This is a necessary condition for the control device to cause the DCAC inverter to perform the power conversion.

  According to the third aspect, it is possible to appropriately permit power supply from the fuel cell unit to the second connection path.

  In the fourth aspect of the present disclosure, for example, the fuel cell power generation system according to any one of the first to third aspects further includes a power supply circuit and a pull-up resistor, and the power supply circuit includes the first power supply circuit. Even when the cutoff relay unit and the second cutoff relay unit are in an OFF state, the pull-up resistor is provided at a position where power is supplied from the first system power source and / or the second system power source. The voltage is supplied to the abnormal input part of the first three-input AND circuit through the above, thereby realizing a state in which the signal input to the abnormal input part of the first three-input AND circuit is an on signal. .

  The control device may not be started immediately after starting the fuel cell power generation system. However, according to the fourth aspect, even when the control device is not activated, a state in which the signal input to the abnormal input unit of the first three-input AND circuit is an on signal is realized. Thereby, even when the control device is not activated, the first cutoff relay unit can be turned on, and electric power flows between the fuel cell unit and the first system power supply via the first cutoff relay unit. be able to.

  In the fifth aspect of the present disclosure, for example, in the fuel cell power generation system according to the fourth aspect, the first connection path includes a system-side portion that connects the first cutoff relay and the first system power supply, Power is supplied from the system side portion to the power supply circuit.

  The way of supplying power to the power supply circuit in the fifth aspect is a specific example of how to supply power to the power supply circuit.

  In the sixth aspect of the present disclosure, for example, in the fuel cell power generation system according to the fourth aspect or the fifth aspect, the fuel cell unit has a control power source, and the operation mode of the fuel cell power generation system is an activation mode. And in the start-up mode, a voltage is supplied from the power supply circuit to the abnormal input portion of the first three-input AND circuit via the pull-up resistor, thereby causing an abnormality in the first three-input AND circuit. A signal input to the input unit is maintained as an ON signal, and the operation unit performs the first ON operation in a state where a signal input to the abnormal input unit of the first three-input AND circuit is maintained as an ON signal. When the first interrupting relay unit is switched from the off state to the on state and the first interrupting relay unit is switched from the off state to the on state, Power is supplied to the control power supply via the first interrupting relay unit, and power is supplied to the control power supply, whereby the control power supply is activated, and after the control power supply is activated, the control power supply When power is supplied to the control device and power is supplied from the control power source to the control device, the control device is activated, and after the control device is activated, the control device is The signal input to the abnormal input portion of the circuit is kept on.

  According to the start mode of the sixth aspect, the control device can be appropriately started. Moreover, the control apparatus can maintain the signal input to the abnormal input part of the second three-input AND circuit after the activation as an ON signal. When the second on operation is performed on the operation unit in this maintained state, the second cutoff relay unit can be switched from the off state to the on state. Thereby, it becomes possible to supply a voltage to a fuel cell unit from a 2nd system power supply via a 2nd interruption | blocking relay part.

  In the seventh aspect of the present disclosure, for example, the fuel cell power generation system according to any one of the first to sixth aspects further includes a leakage detection element disposed at a leakage detection position, and the first system power supply The first path used to guide the electric power to the first load through the first interruption relay part and the leakage detection position in this order, and the second interruption relay part and the leakage detection position from the second power supply There is a second path used to guide power to the second load through in order, and the leakage detection element is shared by the leakage detection of the first load and the leakage detection of the second load.

  In the seventh aspect, the leakage detection element is commonly used for detection of leakage of the first load and leakage of the second load. This configuration is suitable for downsizing the fuel cell power generation system.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the following embodiments.

  FIG. 1 shows a fuel cell power generation system 200 according to this embodiment.

  The fuel cell power generation system 200 can be linked to the first system power supply 11 and the second system power supply 12. Power can be supplied to the fuel cell power generation system 200 from the first system power supply 11 and the second system power supply 12. The fuel cell power generation system 200 can supply power to the second system power supply 12.

  The fuel cell power generation system 200 includes a fuel cell 41, an auxiliary device 44, a reformer 45, a combustor 46, a surplus heater 25, an igniter 21a, a heater 21b, a control power source 47, an outlet 26, A backup boiler 27 and a power supply circuit 100 are included. In the fuel cell power generation system 200, a fuel cell unit 150 is configured.

  Hereinafter, components of the fuel cell power generation system 200 and elements related to the system 200 will be described.

(System power supply 11 and 12)
The first system power supply 11 is a power supply that can output the first AC voltage V _AC1 . The second system power supply 12 is a power supply that can output the second AC voltage V _AC2 . The effective value of the first AC voltage V _AC1 is smaller than the effective value of the second AC voltage V _AC2 . The effective value of the first AC voltage V _AC1 is, for example, 100V. The effective value of the second AC voltage V _AC2 is, for example, 200V.

As shown in FIG. 6, in the present embodiment, the first system power supply 11 and the second system power supply 12 are power supplies that use a commercial power supply 15 as a power supply source. Here, the commercial power source 15 refers to a power source supplied by an electric power company (not limited to so-called 10 electric power companies). Specifically, the first system power supply 11 and the second system power supply 12 use a commercial power supply 15 and three single-phase three-wire lines 16U, 16O, and 16W drawn into the distribution board 17. Realized. The line 16U is a U-phase line, the line 16O is an O-phase line, and the line 16W is a W-phase line. The lines 16U and 16W are ungrounded lines, and the O-phase line is a grounded line (neutral line). Between the lines 16U and the line 16O is applied first AC voltage V _AC1, between the line 16W and the line 16O is applied first AC voltage V _AC1, between the lines 16U and the line 16W is A second AC voltage V _AC2 is applied. The first system power supply 11 is realized by extracting electric power from the commercial power supply 15 via the lines 16U and 16O. However, the 1st system power supply 11 may be implement | achieved by taking out electric power from the commercial power supply 15 via the track | lines 16W and 16O. Second system power supply 12 is realized by extracting power from commercial power supply 15 via lines 16U and 16W.

(Auxiliary power supply 19)
When the commercial power supply 15 fails, the first system power supply 11 and the second system power supply 12 also power out. In the event of a power failure of the first system power supply 11, AC power can be supplied from the auxiliary power supply device 19 to the fuel cell power generation system 200 instead of the first system power supply 11. Specifically, the auxiliary power supply device 19 can supply AC power having a voltage V _AC1 to the fuel cell power generation system 200. The auxiliary power supply device 19 is, for example, a generator or a storage battery.

(Combustor 46 and igniter 21a)
A raw material gas is supplied to the combustor 46. The igniter 21 a generates a spark discharge and ignites the raw material gas of the combustor 46. In the combustor 46, the raw material gas burns and heat is generated. This heat is given to the reformer 45.

(Reformer 45 and heater 21b)
The reformer 45 has a reforming catalyst for advancing the reforming reaction. Water and source gas are supplied to the reformer 45. In the reformer 45, a reforming reaction using a reforming catalyst, water, and a raw material gas is performed. Thereby, hydrogen gas is generated. The generated hydrogen gas is supplied to the fuel cell 41. In one example, the reforming reaction is a steam reforming reaction (CH ₄ + H ₂ O → CO + 3H ₂ ). The source gas is, for example, a hydrocarbon gas such as city gas or LP gas (liquefied petroleum gas). The heater 21b heats the reformer 45.

(Fuel cell 41)
The fuel cell 41 generates power using oxidant gas and hydrogen gas to generate DC power. This direct current power is supplied to the DCDC converter 42. In addition, the fuel cell power generation system 200 boils hot water using the exhaust heat generated during power generation. The boiled hot water is stored in a hot water storage tank (not shown). Hot water stored in the hot water storage tank can be used for hot water supply, heating, and the like. The fuel cell 41 is, for example, a solid polymer fuel cell or a solid oxide fuel cell.

(Auxiliary machine 44)
The auxiliary equipment 44 is equipment that performs operations necessary for the operation of the fuel cell 41. Examples of the auxiliary machine 44 include a blower, a pump, a valve, a flow meter, and a pressure gauge. When it is necessary to start the fuel cell 41, the auxiliary machine 44 performs an operation necessary for the operation of the fuel cell 41 by supplying power from the first system power supply 11, the second system power supply 12, or the auxiliary power supply device 19. After the fuel cell 41 is started, the DC power generated by the fuel cell 41 is supplied to the auxiliary device 44. 1 to 5, the electric circuit for supplying electric power from the fuel cell 41 to the auxiliary device 44 is omitted.

(Surplus heater 25)
There may be a case where the generated power of the fuel cell 41 exceeds the required power of the load of the power supply destination of the fuel cell 41. The surplus heater 25 consumes more power (hereinafter sometimes referred to as surplus power). Thus, the surplus heater 25 prevents reverse power flow from the fuel cell power generation system 200 to the commercial power supply 15. In this embodiment, the heat generated by the surplus heater 25 is used to warm water. The obtained hot water is stored in a hot water storage tank.

(Outlet 26)
The outlet 26 can be supplied with AC power having a voltage V _AC1 . The electrical device to which the outlet 26 is connected is not particularly limited. The electric device is, for example, a refrigerator or a television. Specifically, the outlet 26 is a self-supporting outlet to which AC power is supplied from the fuel cell 41 during the self-sustaining operation of the fuel cell power generation system 200.

(Backup boiler 27)
The backup boiler 27 can be supplied with AC power having a voltage V _AC1 . Specifically, the backup boiler 27 can be supplied with AC power from the fuel cell 41, the first system power supply 11, or the auxiliary power supply device 19. The backup boiler 27 heats water or hot water when the temperature of the water or hot water output from the hot water storage tank is low.

(Power supply circuit 100)
The power supply circuit 100 is used for power supply from the first system power supply 11 to the first load and power supply from the second system power supply 12 to the second load. The power supply circuit 100 includes a first cutoff relay unit 31, a second cutoff relay unit 32, a third cutoff relay unit 33, a disconnection relay unit 34, a first switching relay unit 38, and a second switching relay unit. 39. The power supply circuit 100 includes a leakage detection element 51, a power supply circuit 52, and a leakage detection circuit 58. The power supply circuit 100 includes an ACDC converter 22, a DCDC converter 42, and a DCAC inverter 43. The power supply circuit 100 includes a power recovery detection circuit 71. The power supply circuit 100 has a control power supply 47. The power supply circuit 100 includes a connection unit 61, a connection unit 62, a connection unit 63, and a connection unit 64. The power supply circuit 100 includes at least one substrate 80. Further, the power supply circuit 100 includes a first power supply path 91, a second power supply path 92, and a third power supply path 93. Hereinafter, the position where the leakage detection element 51 is disposed may be referred to as a leakage detection position 51p. Of course, the components of the power supply circuit 100 are also components of the fuel cell power generation system 200.

  In the present embodiment, each of the igniter 21a and the heater 21b corresponds to the first load. The ACDC converter 22 corresponds to the second load. The number of first loads may be one or plural. The kind of 1st load is not specifically limited. These points are the same for the second load.

(First feeding path 91)
In the 1st electric power feeding path 91, the 1st interruption | blocking relay part 31 and the leakage detection position 51p appear in order toward the 1st load from the 1st system power supply 11. FIG. The first power supply path 91 is used to guide power from the first system power supply 11 to the first load through the first interrupting relay unit 31 and the leakage detection position 51p in this order. As shown in FIG. 6, in the present embodiment, the first power supply path 91 is configured by two single-phase two-wire lines.

(Second feeding path 92)
In the second power supply path 92, the second cutoff relay unit 32 and the leakage detection position 51p appear in order from the second system power supply 12 toward the second load. The second power supply path 92 is used to guide power from the second system power supply 12 to the second load via the second cutoff relay unit 32 and the leakage detection position 51p in this order. As shown in FIG. 6, in the present embodiment, a part of the second power feeding path 92 is configured by three single-phase three-wire lines. Specifically, the part of the second power supply path 92 closer to the second system power supply 12 than the first switching relay unit 38 is configured by three single-phase three-wire lines. The portion between the first switching relay unit 38 and the second load (ACDC converter 22 in the present embodiment) in the second power feeding path 92 is two lines except for the neutral line in the single-phase three-wire system, that is, 2 It is composed of a non-grounded line of books.

(Third power supply path 93)
In the third power feeding path 93, the leakage detection position 51 p and the third cutoff relay unit 33 appear in order from the fuel cell 41 toward the outlet 26. The third power supply path 93 is used to guide power from the fuel cell 41 to the outlet 26 through the leakage detection position 51p and the third cutoff relay unit 33 in this order. The third power supply path 93 has a direct current portion from the fuel cell 41 to the DCAC inverter 43 via the DCDC converter 42. The third power supply path 93 includes a first AC part that extends from the DCAC inverter 43 to the first switching relay unit 38 via the disconnection relay unit 34. The third power supply path 93 includes a second AC portion that extends from the first switching relay unit 38 to the outlet 26 through the leakage detection position 51p, the second switching relay unit 39, and the third cutoff relay unit 33 in this order. The first AC portion is composed of two lines except for the neutral line in the single-phase three-wire system. The second AC portion is constituted by two single-phase two-wire lines.

(DCDC converter 42)
The DCDC converter 42 converts the DC power generated by the fuel cell 41 into DC power having a different voltage. In the present embodiment, the DCDC converter 42 boosts the DC power generated by the fuel cell 41. The converted DC power is supplied to the DCAC inverter 43.

(DCAC inverter 43)
The DCAC inverter 43 converts the DC power input from the DCDC converter 42 into AC power. Specifically, the DCAC inverter 43 can convert DC power into AC power having a voltage V _AC1 and AC power having a voltage V _AC2 .

(ACDC converter 22)
The ACDC converter 22 converts AC power supplied from the first system power supply 11, the second system power supply 12, or the auxiliary power supply device 19 into DC power. The obtained DC power is supplied to the auxiliary machine 44 and the control power supply 47. The fuel cell power generation system 200 can perform cutoff control of the ACDC converter 22. The cutoff control refers to control for prohibiting the output of a DC voltage from the ACDC converter 22 to the auxiliary equipment 44 and the control power supply 47.

(Interruption relay units 31-33 and disconnection relay unit 34)
The 1st interruption relay part 31, the 2nd interruption relay part 32, the 3rd interruption relay part 33, and the disconnection relay part 34 can take an ON state or an OFF state. An on state refers to a state that allows current to flow through it. The off state refers to a state in which current is prohibited from flowing through itself. In this specification, switching from an on state to an off state may be expressed as blocking.

  In the present embodiment, the first cutoff relay unit 31 is provided on two single-phase two-wire lines constituting the first power supply path 91, in this example, on the U-phase line and the O-phase line. . Specifically, the first cutoff relay unit 31 includes a U-phase relay and an O-phase relay. The U-phase relay is provided on the U-phase line. The O-phase relay is provided on the O-phase line.

  In the present embodiment, the second cutoff relay unit 32 is provided on three single-phase three-wire lines constituting the second power feeding path 92, that is, on the U-phase line, the W-phase line, and the O-phase line. It has been. Specifically, the second cutoff relay unit 32 includes a U-phase relay, a W-phase relay, and an O-phase relay. The U-phase relay is provided on the U-phase line. The W-phase relay is provided on the W-phase line. The O-phase relay is provided on the O-phase line.

  In the present embodiment, the third cutoff relay unit 33 is provided on two single-phase two-wire lines constituting the third feeding path 93 at the position of the relay unit 33, specifically on the U-phase line and the O-phase line. It is provided on the phase line. Specifically, the 3rd cutoff relay part 33 has a U-phase relay and an O-phase relay. The U-phase relay is provided on the U-phase line. The O-phase relay is provided on the O-phase line.

  In the present embodiment, the disconnecting relay unit 34 is provided on two lines excluding the neutral line among the three single-phase three-wire systems, that is, on the U-phase line and the W-phase line. Specifically, the disconnection relay unit 34 includes a U-phase relay and a W-phase relay. The U-phase relay is provided on the U-phase line. The W-phase relay is provided on the W-phase line.

  In this embodiment, the relay of each phase of the 1st cutoff relay part 31, the 2nd cutoff relay part 32, the 3rd cutoff relay part 33, and the disconnection relay part 34 is a mechanical relay.

  As described with reference to FIG. 6, the first system power supply 11 can also be realized by extracting power from the commercial power supply 15 via the lines 16W and 16O. In this case, the first power supply path 91 is configured by a W-phase line and an O-phase line. The first cutoff relay unit 31 has a W-phase relay instead of the U-phase relay, and the W-phase relay is provided on the W-phase line. This also applies to the third cutoff relay unit 33.

(Switching relay units 38 and 39)
The first switching relay unit 38 and the second switching relay unit 39 switch which electric circuit and which electric circuit are electrically connected.

(Leakage detection element 51)
The leakage detection element 51 is shared by the leakage detection of the first load and the leakage detection of the second load. Specifically, the leakage detection element 51 is also used for leakage detection of the electrical device to which the outlet 26 is connected. Such common use of the leakage detection element 51 is suitable for miniaturization of the fuel cell power generation system 200. This sharing is also advantageous from the viewpoint of cost reduction.

  As described above, in this embodiment, each of the igniter 21a and the heater 21b corresponds to the first load, and the ACDC converter 22 corresponds to the second load. Therefore, in this embodiment, the leakage detection element 51 is shared by the igniter 21a, the heater 21b, and the ACDC converter 22, and more specifically, is also shared by the leakage of the electrical device to which the outlet 26 is connected.

  In the present embodiment, the leakage detection element 51 is a single element. The leakage detection element 51 supplies an output to the leakage detection circuit 58 when it reacts to the leakage.

  In the present embodiment, when leakage is detected using the leakage detection element 51, the first cutoff relay unit 31 and the second cutoff relay unit 32 are blocked. Specifically, when a leakage is detected using the leakage detection element 51, the third cutoff relay unit 33 is also cut off. This configuration is advantageous from the viewpoint of ensuring the safety of the user of the fuel cell power generation system 200.

  In the present embodiment, the leakage detection element 51 is a zero-phase current transformer. The zero-phase current transformer includes a core having a through hole. Two through-holes of the single-phase two-wire system constituting the first power feeding path 91 at the leakage detection position 51p and the single-phase three-wire system 3 constituting the second feeding path 92 at the leakage detection position 51p The line of the book penetrates.

(Power supply circuit 52)
The power supply circuit 52 takes out electric power from a portion of the first power supply path 91 on the first system power supply 11 side with respect to the first cutoff relay unit 31. The extracted power is supplied to the leakage detection circuit 58. As described above, the power supply circuit 52 functions as a power supply for the leakage detection circuit 58.

  In the present embodiment, the power supply circuit 52 constitutes an insulated power supply. Hereinafter, the power supply circuit 52 may be referred to as an insulated power supply 52. As shown in FIG. 6, the insulated power supply 52 includes a primary side portion 52a and a secondary side portion 52b. The primary part 52a is a so-called charging unit. The secondary part 52b is a so-called non-charging part. The primary side part 52a and the secondary side part 52b are insulated from each other.

The primary side portion 52 a is connected to the first power supply path 91. The first AC voltage V _AC1 is applied from the first power supply path 91 to the primary side portion 52a.

  The secondary part 52 b operates at the reference potential of the DCAC inverter 43. Note that the reference potential may not be the ground potential.

In the present embodiment, the insulated power supply 52 includes an insulating transformer 53 and a rectifier circuit 54. Insulating transformer 53 includes a primary side winding 53a and a secondary side winding 53b. A first AC voltage V _AC1 is applied to the primary winding 53a. The insulating transformer 53 steps down the first AC voltage V _AC1 to the third AC voltage V _AC3 . The third AC voltage V _AC3 is output to the secondary winding 53b. The rectifier circuit 54 converts the third AC voltage V _AC3 into a DC voltage V _DC1 .

In the present embodiment, the rectifier circuit 54 includes a diode 56 and a capacitor 55. The diode 56 has an anode 56a and a cathode 56c. The secondary winding 53b, the anode 56a, the cathode 56c, and the capacitor 55 are arranged in this order. The diode 56 rectifies the third AC voltage V _AC3 . Capacitor 55 smoothes the output voltage from diode 56. As a result, a DC voltage V _DC1 appears between one end 55m and the other end 55n of the capacitor 55. In short, the diode 56 and the capacitor 55 generate the DC voltage V _DC1 by half-wave rectification.

(Leakage detection circuit 58)
The leakage detection circuit 58 detects the leakage of the first load and the second load in cooperation with the leakage detection element 51. Specifically, the leakage detection circuit 58 detects the leakage of the electrical device to which the outlet 26 is connected in cooperation with the leakage detection element 51.

  When the leakage detection is performed by the function of the leakage detection circuit 58, the first cutoff relay unit 31 and the second cutoff relay unit 32 are blocked. Specifically, in this case, the third cutoff relay unit 33 is also cut off.

As shown in FIG. 6, in the present embodiment, the leakage detection circuit 58 is connected to the secondary portion 52b. The leakage detection circuit 58 is supplied with electric power and a DC voltage V _DC1 from the secondary side portion 52b. The leakage detection circuit 58 operates at the reference potential of the DCAC inverter 43. In the present embodiment, the leakage detection circuit 58 detects a leakage using the detection value of the leakage detection element 51. The leakage detection circuit 58 cuts off the relay units 31, 32, and 33 when detecting leakage.

(Recovery detection circuit 71)
The power recovery detection circuit 71 periodically acquires a detection signal from a portion of the second power supply path 92 that is closer to the second system power supply 12 than the second cutoff relay unit 32. Based on the acquired detection signal, the power recovery detection circuit 71 determines whether or not the power failure of the second system power supply 12 has been canceled (whether power has been recovered). Further, the power recovery detection circuit 71 determines whether or not the second system power supply 12 has failed due to the detection signal.

In the present embodiment, the power recovery detection circuit 71 extracts a voltage as a detection signal from the above portion. When the extracted voltage is the second AC voltage V _AC2 , it is determined that the power failure of the second system power supply 12 has been canceled. It is also possible to detect that the second system power supply 12 has been restored by another method. Other than the magnitude of the voltage, for example, it can be determined whether or not the second system power supply 12 has been restored with the frequency of the voltage, the cycle of zero crossing, or the like. For example, the power recovery detection circuit 71 can be realized using a voltage sensor and a microcomputer.

  The power recovery detection circuit 71 can detect a power failure based on the magnitude of the voltage, the frequency of the voltage, the zero crossing, and the like, as in the case of power recovery detection. In one example, the power recovery detection circuit 71 determines that the second system power supply 12 is out of power when the effective value of the extracted voltage is equal to or less than a threshold value (for example, approximately zero). In another example, the presence or absence of a power failure is determined based on the presence or absence of a zero cross in the system voltage. In this specific example, the power recovery detection circuit 71 determines the presence or absence of a power failure based on the presence or absence of a zero cross of the extracted voltage.

  In the present embodiment, the timing of the occurrence of a power failure in the commercial power supply 15 is the same as the timing of the occurrence of a power failure in the first system power supply 11 and the second system power supply 12. The power recovery timing in the commercial power supply 15 is the same as the power recovery timing in the first system power supply 11 and the second system power supply 12. In the present embodiment, when a power failure is detected by the power recovery detection circuit 71, the fuel cell power generation system 200 causes a power failure at the first system power source 11, a power failure occurs at the second system power source 12, and a commercial power source. 15 determines that a power failure has occurred. Further, when power recovery is detected by the power recovery detection circuit 71, it is determined that the first system power supply 11 has recovered, the second system power supply 12 has recovered, and the commercial power supply 15 has recovered.

  In the fuel cell power generation system 200 of the present embodiment, the second cutoff relay unit 32 is cut off when a power failure occurs in the commercial power supply 15. Specifically, when the power recovery detection unit 71 detects a power failure, the second cutoff relay unit 32 is cut off. More specifically, this blocking is performed by the control device 180 described later. In the fuel cell power generation system 200 of the present embodiment, the second cutoff relay unit 32 operates not only as a relay unit that operates when a leakage is detected, but also as a relay unit that operates when a power failure is detected. This configuration is suitable for miniaturization of the fuel cell power generation system 200.

  In the fuel cell power generation system 200 of the present embodiment, a switching device is configured. The switching device includes a leakage detection circuit 58 and a power recovery detection circuit 71. When the leakage detection circuit 58 detects a leakage, the switching device switches the first cutoff relay unit 31, the second cutoff relay unit 32, and the third cutoff relay unit 33 to an off state. In the present embodiment, when the power recovery detection circuit 71 detects a power failure, the switching device switches the second cutoff relay unit 32 to the off state. Moreover, in this embodiment, the switching apparatus switches the 1st interruption | blocking relay part 31 to an OFF state after a power failure detection and before independent operation start.

(Control power supply 47)
The control power supply 47 supplies electric power for control to elements inside and outside the fuel cell unit 150. The control power supply 47 is a power supply that uses the first system power supply 11, the second system power supply 12, or the auxiliary power supply device 19 as a power supply source. Specifically, the control power supply 47 is realized by power supplied from the first system power supply 11, the second system power supply 12, or the auxiliary power supply device 19 through the ACDC converter 22. In this example, the voltage of the supplied power is defined by the transformation by the ACDC converter 22 as is the power supplied to the auxiliary machine 44. After startup of the fuel cell 41, direct current power generated by the fuel cell 41 is supplied to the control power supply 47. In FIG. 1 to FIG. 5, the electric circuit for supplying electric power from the fuel cell 41 to the control power source 47 is omitted.

(Substrate 80)
On at least one substrate 80, the first cutoff relay unit 31, the second cutoff relay unit 32, the third cutoff relay unit 33, the disconnect relay unit 34, the first switching relay unit 38, and the second A switching relay unit 39, a power supply circuit 52, a leakage detection circuit 58, an ACDC converter 22, a DCDC converter 42, a DCAC inverter 43, a power recovery detection circuit 71, and a control power supply 47 are provided.

  Specifically, in the present embodiment, at least one substrate 80 includes a first substrate 81 and a second substrate 82. On the first substrate 81, the first cutoff relay unit 31, the second cutoff relay unit 32, the third cutoff relay unit 33, the second switching relay unit 39, the power supply circuit 52, the leakage detection circuit 58, , A power recovery detection circuit 71 is provided. On the second substrate 82, a disconnect relay unit 34, a first switching relay unit 38, an ACDC converter 22, a DCDC converter 42, a DCAC inverter 43, and a control power supply 47 are provided.

  In the present embodiment, the first power supply path 91 and the second power supply path 92 have an upper part of the substrate that exists on at least one substrate 80. The leakage detection position 51p is a position outside the at least one substrate 80. A portion of the first power supply path 91 on the substrate is divided by a leakage detection position 51p. A portion of the second power supply path 92 on the substrate is divided by a leakage detection position 51p. In the illustrated example, these paths 91 and 92 are divided into a region on the first substrate 81 and a region on the second substrate 82. However, the same division can also be realized by using one substrate as at least one substrate 80 and hollowing out the substrate.

  If it does as mentioned above, even if it is a case where it is difficult to arrange | position the leak detection element 51 on a board | substrate, the fuel cell power generation system 200 provided with the leak detection element 51 is realizable. For example, when the leakage detection element 51 is a zero-phase current transformer, the leakage detection element 51 can be easily arranged in this manner. In particular, in the present embodiment, the leakage detection element 51 is a zero-phase current transformer, and five lines penetrate the through-holes of the zero-phase current transformer. In this case, it is not always easy to make the zero-phase current transformer small, and it is not always easy to arrange the zero-phase current transformer on the substrate. However, by arranging the leakage detection element 51 in the portion outside the substrate, the difficulty of such arrangement is alleviated.

(Connection 61)
The connection portion 61 is provided at the end portion of the first substrate 81. In the first power supply path 91, the connection unit 61 is closer to the first system power supply 11 than the first cutoff relay unit 31. In the second power supply path 92, the connecting portion 61 is located closer to the second system power supply 12 than the second cutoff relay portion 32.

(Connection 62)
The connection part 62 is provided at the end of the first substrate 81. In the third power supply path 93, the connection part 62 is present on the outlet 26 side with respect to the third cutoff relay part 33. In addition, the connection unit 62 is located closer to the backup boiler 27 than the second switching relay unit 39 in the electric path connecting the second switching relay unit 39 and the backup boiler 27.

(Connection 63 and Connection 64)
The connection part 63 is provided at the end of the first substrate 81. The connection portion 64 is provided at the end portion of the second substrate 82. In the first power supply path 91, the part of the leakage detection position 51 p is between the connection part 63 and the connection part 64. In the second power supply path 92, the part of the leakage detection position 51 p is between the connection part 63 and the connection part 64.

  Hereinafter, examples of operation modes of the fuel cell power generation system 200 will be described with reference to FIGS. In these drawings, the thick line indicates a portion where a voltage is applied. Hereinafter, for convenience of explanation, it is assumed that power is supplied to the element to which the voltage is supplied. In fact, considering standby power and the like, power can be consumed by each element even when each element is not performing its intended operation. However, it is not essential to supply power to elements that do not require power. For example, in the standby mode and the auxiliary power usage mode, power need not be supplied to the surplus heater 25.

(Standby mode)
The standby mode shown in FIG. 2 can be executed when the commercial power supply 15 is not powered down. In the standby mode, the first cutoff relay unit 31 is in the on state. The 2nd interruption | blocking relay part 32 is in an ON state. The third cutoff relay unit 33 is in an on state. The disconnect relay unit 34 is in an off state. The second switching relay unit 39 electrically connects the first cutoff relay unit 31 to the backup boiler 27, the igniter 21a, the heater 21b, and the first switching relay unit 38. The first switching relay unit 38 electrically connects the second cutoff relay unit 32 to the ACDC converter 22, the surplus heater 25, and the disconnection relay unit 34.

In the standby mode, AC power of voltage V _AC1 is supplied from the first system power supply 11 to the fuel cell power generation system 200. On the other hand, AC power of voltage V _AC2 is supplied from the second power supply 12 to the fuel cell power generation system 200.

Specifically, the AC power of the voltage V _AC1 passes through the first cutoff relay unit 31 and the second switching relay unit 39 in this order from the first system power supply 11. Part of the AC power that has passed through the second switching relay unit 39 is guided to the backup boiler 27. Another part of the AC power that has passed through the second switching relay unit 39 passes through the leakage detection position 51p. Part of the AC power that has passed through the leakage detection position 51p is guided to the igniter 21a. Another part of the AC power that has passed through the leakage detection position 51p is led to the heater 21b.

Further, the AC power of the voltage V _AC2 passes from the second power supply 12 through the second cutoff relay unit 32, the leakage detection position 51p, and the first switching relay unit 38 in this order. Part of the AC power that has passed through the first switching relay unit 38 is guided to the surplus heater 25. Another part of the AC power that has passed through the first switching relay unit 38 is guided to the ACDC converter 22. The AC power guided to the ACDC converter 22 is converted to DC power. The obtained DC power is guided to the auxiliary machine 44 and the control power supply 47.

(First power generation mode)
The first power generation mode shown in FIG. 3 can be executed when the commercial power supply 15 is not powered down. In the first power generation mode, the first cutoff relay unit 31 is in the on state. The 2nd interruption | blocking relay part 32 is in an ON state. The third cutoff relay unit 33 is in an on state. The disconnect relay unit 34 is in an on state. The second switching relay unit 39 electrically connects the first cutoff relay unit 31 to the backup boiler 27, the igniter 21a, the heater 21b, and the first switching relay unit 38. The first switching relay unit 38 electrically connects the second cutoff relay unit 32 to the ACDC converter 22, the surplus heater 25, and the disconnection relay unit 34.

  In the first power generation mode, the fuel cell 41 generates power. The electric power generated by the fuel cell 41 passes through the DCDC converter 42, the DCAC inverter 43, the disconnection relay unit 34, the first switching relay unit 38, the leakage detection position 51p, and the second cutoff relay unit 32 in this order in FIG. It is led to the distribution board 17 shown. This electric power is then led to the backup boiler 27, the igniter 21a, and the heater 21b as in the standby mode. The power guided to the distribution board 17 can be guided to other loads via a branch breaker (not shown) in the distribution board 17.

Specifically, DC power is generated by the fuel cell 41. The DCDC converter 42 converts this direct current power into direct current power having a different voltage. Specifically, the DCDC converter 42 boosts this DC power. The DCAC inverter 43 converts the DC power after the conversion into AC power having the voltage _VAC2 . The obtained AC power of the voltage V _AC2 is guided to the distribution board 17 through the disconnection relay unit 34, the first switching relay unit 38, the leakage detection position 51p, and the second cutoff relay unit 32 in this order. As understood from FIG. 6, the AC power of the voltage V _AC2 guided to the distribution board 17 flows through the U-phase line 16U and the W-phase line 16W. A part of this AC power is taken out from the U-phase line 16U and the O-phase line 16O. The extracted power is led to the backup boiler 27, the igniter 21a, and the heater 21b in the same manner as the power supplied from the first system power supply 11 to the fuel cell power generation system 200 in the standby mode. The power guided to the distribution board 17 can be guided to other loads via a branch breaker (not shown) in the distribution board 17.

  In the first power generation mode, the generated power of the fuel cell 41 may be larger than the total required power of the load connected to the backup boiler 27, the igniter 21a, the heater 21b, and the branch breaker. In that case, surplus power is consumed by the surplus heater 25. In addition, there may be a case where the required power of the load at the connection destination of the backup boiler 27, the igniter 21a, the heater 21b, and the branch breaker cannot be covered only with the power generated by the fuel cell 41. In that case, the electric power derived from the commercial power supply 15 is supplied to these together with the electric power derived from the fuel cell 41.

  In the first power generation mode, the cutoff control of the ACDC converter 22 is performed. For this reason, power is not supplied to the auxiliary machine 44 and the control power supply 47 via the ACDC converter 22. As described above, although not shown, the fuel cell power generation system 200 has an electric circuit for supplying electric power from the fuel cell 41 to the auxiliary device 44 and the control power supply 47. In the first power generation mode, power is supplied from the fuel cell 41 to the auxiliary device 44 and the control power supply 47 through the electric circuit. This also applies to the second power generation mode described later.

(Second power generation mode)
The second power generation mode shown in FIG. 4 can be executed at the time of a power failure of the commercial power supply 15. In the second power generation mode, the first cutoff relay unit 31 is in an off state. The second cutoff relay unit 32 is in an off state. The third cutoff relay unit 33 is in an on state. The disconnect relay unit 34 is in an on state. The first switching relay unit 38 electrically connects the disconnection relay unit 34, the surplus heater 25, and the ACDC converter 22 to the igniter 21 a, the heater 21 b, the second switching relay unit 39, and the backup boiler 27. The second switching relay unit 39 electrically connects the backup boiler 27, the igniter 21 a, the heater 21 b, and the first switching relay unit 38 with the third cutoff relay unit 33.

  In the second power generation mode, power generation is performed by the fuel cell 41. Since this power generation is performed at the time of a power failure of the commercial power supply 15, the second power generation mode can be referred to as a self-sustained operation mode. Unlike the first power generation mode, the electric power generated by the fuel cell 41 is not guided to the distribution board 17. In the second power generation mode, the electric power generated by the fuel cell 41 is guided to the backup boiler 27 and the outlet 26.

Specifically, the power generated by the fuel cell 41 is guided to the DCAC inverter 43 via the DCDC converter 42 as in the first power generation mode. Unlike the first power generation mode, the DCAC inverter 43 converts the DC power after conversion by the DCDC converter 42 into AC power of the voltage V _AC1 . The obtained AC power of the voltage V _AC1 passes through the disconnecting relay unit 34, the first switching relay unit 38, and the leakage detection position 51p in this order. Part of the AC power that has passed through the leakage detection position 51p is led to the backup boiler 27. Another part of the AC power that has passed through the leakage detection position 51p is led to the outlet 26 via the second switching relay unit 39 and the third cutoff relay unit 33 in this order. The electric power guided to the outlet 26 is guided to the load to which the outlet 26 is connected.

  In the second power generation mode, DC power generated by the fuel cell 41 instead of the power supply circuit 52 is supplied to the leakage detection circuit 58. The fuel cell power generation system 200 has an electric circuit and a switch (not shown) for supplying this electric power.

  As understood from FIG. 4, in the present embodiment, the fuel cell power generation system 200 maintains the third cutoff relay unit 33 in the ON state during the period when the commercial power supply 15 is out of power, and the third power feeding path 93. Can be used to perform a self-sustaining operation of supplying power from the fuel cell 41 to the outlet 26. It should be noted that the occurrence of a power failure can be detected by the fuel cell power generation system 200 as described above.

  In the present embodiment, when leakage is detected using the leakage detection element 51 during the period of self-sustained operation, the third cutoff relay unit 33 is blocked and the third cutoff relay unit 33 is locked in the off state. The Such a lock can contribute to ensuring the safety of the user of the fuel cell power generation system 200. In addition, since the lock is made, the user of the fuel cell power generation system 200 can know that a leakage has occurred in the electrical device to which the outlet 26 is connected. This locking is continued until, for example, the fuel cell power generation system 200 determines that the first system power supply 11 has recovered. The lock is not particularly limited as long as it prevents the third cutoff relay unit 33 from being switched from the off state to the on state. In the present embodiment, specifically, the locking is performed by electrically latching the third cutoff relay unit 33 and maintaining it in the off state.

(Auxiliary power usage mode)
The auxiliary power use mode shown in FIG. 5 can be executed when the commercial power supply 15 is powered off. In the auxiliary power usage mode, the first cutoff relay unit 31 is in the on state. The second cutoff relay unit 32 is in an off state. The third cutoff relay unit 33 is in an on state. The disconnect relay unit 34 is in an off state. The second switching relay unit 39 electrically connects the first cutoff relay unit 31 to the backup boiler 27, the igniter 21a, the heater 21b, and the first switching relay unit 38. The first switching relay unit 38 electrically connects the second switching relay unit 39, the backup boiler 27, the igniter 21a, and the heater 21b to the ACDC converter 22, the surplus heater 25, and the disconnection relay unit 34.

In the auxiliary power usage mode, the power supply source to the fuel cell power generation system 200 is changed from the first system power supply 11 to the auxiliary power supply device 19. In the auxiliary power usage mode, AC power of voltage V _AC1 is supplied from the auxiliary power supply device 19 to the fuel cell power generation system 200. Specifically, in the auxiliary power usage mode, the AC power having the voltage V _AC1 passes from the auxiliary power supply 19 through the first cutoff relay unit 31 and the second switching relay unit 39 in this order. Part of the AC power that has passed through the second switching relay unit 39 is guided to the backup boiler 27. Another part of the AC power that has passed through the second switching relay unit 39 passes through the leakage detection position 51p. Part of the AC power that has passed through the leakage detection position 51p is guided to the igniter 21a. Another part of the AC power that has passed through the leakage detection position 51p is led to the heater 21b. Still another part of the AC power that has passed through the leakage detection position 51p passes through the first switching relay unit 38. Part of the AC power that has passed through the first switching relay unit 38 is guided to the surplus heater 25. Another part of the AC power that has passed through the first switching relay unit 38 is guided to the ACDC converter 22. The AC power guided to the ACDC converter 22 is converted to DC power. The obtained DC power is guided to the auxiliary machine 44 and the control power supply 47.

  According to the auxiliary power supply utilization mode, power can be supplied from the auxiliary power supply device 19 to the auxiliary machine 44 when a power failure occurs in the commercial power supply 15 when the fuel cell 41 is not generating power. With this power supply, the power generation of the fuel cell 41 can be started, and the second power generation mode can be started. According to the auxiliary power usage mode, power can be supplied from the auxiliary power supply device 19 to the control power supply 47 even when the fuel cell 41 is not generating power and the commercial power supply 15 is out of power. Further, according to the auxiliary power usage mode, even when the fuel cell 41 is not generating power and the commercial power supply 15 is out of power, power can be supplied from the auxiliary power supply 19 to the backup boiler 27 and hot water can be supplied. Can be boiled.

  In the standby mode of FIG. 2, the first power generation mode of FIG. 3, and the auxiliary power usage mode of FIG. 5, power is supplied to the first loads 21 a and 21 b using the first power supply path 91. In these modes, the leakage detection element 51 is used for leakage detection of the first loads 21a and 21b. In the standby mode, power is supplied to the second load 22 using the second power supply path 92. In the standby mode, the leakage detection element 51 is used for detection of leakage of the second load 22. In the second power generation mode of FIG. 4, power is supplied to the outlet 26 using the third power supply path 93. In the second power generation mode, the leakage detection element 51 is used for leakage detection of a load to which the outlet 26 is connected.

  As can be understood from FIGS. 1 to 5, in the present embodiment, the first interruption relay unit 31, the portion of the leakage detection position 51 p in the first feeding path 91, the portion of the leakage detection position 51 p in the second feeding path 92, and the first The two cutoff relay units 32 are not electrically connected in this order.

  Temporarily, the 1st interruption | blocking relay part 31, the part of the earth leakage detection position 51p in the 1st electric power feeding path 91, the part of the earth leakage detection position 51p in the 2nd electric power feeding path 92, and the 2nd interruption | blocking relay part 32 are electrically connected in this order. Suppose that In such a case, the leakage current of one load causes an unbalance current to flow not only in one of the leakage detection position 51p portion in the first feeding path 91 and the leakage detection position 51p portion in the second feeding path 92. There is a risk. When unbalanced current is generated in both parts in this way, these unbalanced currents interfere with leakage detection based on the other unbalanced current, and leakage detection is not performed even though unbalanced current is generated. Can lead to the situation. For example, when the leakage detection element 51 is a zero-phase current transformer, the magnetic fields generated by both unbalanced currents cancel each other, and a situation may occur in which leakage detection is not performed by the leakage detection element 51. However, according to the present embodiment, such a situation can be avoided.

[Control of interrupting relay units 31, 32 and 33]
As described above, the switching device is responsible for switching the interrupting relay units 31, 32, and 33. Hereinafter, the switching device will be described in detail. Hereinafter, the fuel cell unit 150, the first connection path 141, and the second connection path 142 will be described together.

(Fuel cell unit 150)
As shown in FIG. 1, the fuel cell unit 150 includes a fuel cell 41, an auxiliary device 44, a reformer 45, a combustor 46, a surplus heater 25, an igniter 21 a, a heater 21 b, and a control power supply 47. A disconnection relay unit 34, a first switching relay unit 38, an ACDC converter 22, a DCDC converter 42, and a DCAC inverter 43. The fuel cell unit 150 generates power. Specifically, the fuel cell unit 150 generates power using the fuel cell 41.

(First connection path 141 and second connection path 142)
The fuel cell power generation system 200 has a first connection path 141 and a second connection path 142. In the present embodiment, the first connection path 141 corresponds to a portion of the first power supply path 91 that is closer to the first system power supply 11 than the fuel cell unit 150. In the present embodiment, the second connection path 142 corresponds to a portion of the second power feeding path 92 that is closer to the second system power supply 12 than the fuel cell unit 150.

  The fuel cell power generation system 200 can be connected to the first system power supply 11 using the first connection path 141. The fuel cell power generation system 200 can be connected to the second power supply 12 using the second connection path 142.

  A first cutoff relay unit 31 is provided on the first connection path 141. On the second connection path 142, the second cutoff relay unit 32 is provided.

  The fuel cell unit 150 can be connected to the first system power source 11 using the first connection path 141. The fuel cell unit 150 can be connected to the second system power source 12 using the second connection path 142.

  In the present embodiment, the first connection path 141 is constituted by two single-phase two-wire lines. The second connection path 142 is configured by three single-phase three-wire lines. The first interrupting relay unit 31 is provided on two single-phase two-wire lines constituting the first connection path 141. In this example, the first cutoff relay unit 31 is provided on the U-phase line and the O-phase line of the first connection path 141.

  As described above, the first system power supply 11 can also be realized by extracting electric power from the commercial power supply 15 via the lines 16W and 16O. In this case, the first cutoff relay unit 31 is provided on the W-phase line and the O-phase line of the first connection path 141.

  In the present embodiment, the power supply circuit 52 is located at a position where power is supplied from the first system power supply 11 and / or the second system power supply 12 even when the first cutoff relay unit 31 and the second cutoff relay unit 32 are in the off state. Is provided. Specifically, in the present embodiment, the first connection path 141 has a system side part that connects the first cutoff relay 31 and the first system power supply 11, and power is supplied from the system side part to the power supply circuit 52. Supplied. More specifically, in the present embodiment, as shown in FIG. 6, the primary side portion 52 a of the insulated power supply 52 is connected to the system side portion of the first connection path 141.

  The power recovery detection unit 71 periodically acquires a detection signal from a portion of the second connection path 142 closer to the second system power supply 12 than the second cutoff relay unit 32.

(Switching device 199)
In the present embodiment, a switching device 199 shown in FIG. 7 is configured. In FIG. 7, some of the components of the fuel cell power generation system 200 are omitted.

  The switching device 199 includes a leakage detection circuit 58, a power recovery detection circuit 71, a first 3-input AND circuit 161, a second 3-input AND circuit 162, a 2-input AND circuit 163, and a pull-up resistor 171. The operation unit 190 and the control device 180 are provided. These elements are also constituent elements of the fuel cell power generation system 200.

  The first three-input AND circuit 161 has three input units, that is, a leakage input unit 161L, an abnormal input unit 161X, and an operation input unit 161M. An ON signal can be input to these three input portions 161L, 161X, and 161M. The first three-input AND circuit 161 maintains the first cutoff relay unit 31 in the on state during the period in which the first on condition is satisfied. On the other hand, the first three-input AND circuit 161 maintains the first cutoff relay unit 31 in the OFF state during a period in which the first ON condition is not satisfied. The first ON condition is a condition in which an ON signal is input to the three input units 161L, 161X, and 161M of the first three-input AND circuit 161. The fact that the first ON condition is not satisfied means that the three input units 161L, 161X, and 161M include at least one input unit to which no ON signal is input.

  The second three-input AND circuit 162 has three input units, that is, a leakage input unit 162L, an abnormal input unit 162X, and an operation input unit 162M. An ON signal can be input to these three input sections 162L, 162X, and 162M. The second three-input AND circuit 162 maintains the second cutoff relay unit 32 in the on state during the period in which the second on condition is satisfied. On the other hand, the second three-input AND circuit 162 maintains the second cutoff relay unit 32 in the OFF state during the period in which the second ON condition is not satisfied. The second ON condition is a condition in which an ON signal is input to the three input units 162L, 162X, and 162M of the second three-input AND circuit 162. The fact that the second ON condition is not satisfied means that at least one input unit to which no ON signal is input is included in the three input units 162L, 162X, and 162M.

  The 2-input AND circuit 163 has two input parts, a leakage input part 163L and a power recovery input part 163R. An ON signal can be input to these two input units 163L and 163R. The 2-input AND circuit 163 transmits a voltage supply detection signal to the control device 180 during a period in which the third ON condition is satisfied. The 2-input AND circuit 163 does not transmit the voltage supply detection signal to the control device 180 in a period in which the third ON condition is not satisfied. The third ON condition is a condition that an ON signal is input to the two input units 163L and 163R of the two-input AND circuit 163. The fact that the third ON condition is not satisfied means that the two input parts 163L and 163R include at least one input part to which no ON signal is input.

  In the present embodiment, the first 3-input AND circuit 161, the second 3-input AND circuit 162, and the 2-input AND circuit 163 are discrete circuits. However, these AND circuits 161, 162 and 163 may be constituted by an IC (Integrated Circuit) or the like.

  The operation unit 190 is an operation unit that can be operated by a person. The operation unit 190 includes a first operation switch 191, a second operation switch 192, and a leakage test switch 193. The first operation switch 191, the second operation switch 192, and the leakage test switch 193 are switches that can be operated by a person.

  The operation unit 190 receives a first on operation, a first off operation, a second on operation, a second off operation, a test operation, and a release operation.

  The first ON operation is an operation for obtaining a state in which an ON signal is input to the operation input unit 161M of the first three-input AND circuit 161. The first off operation is an operation for obtaining a state in which no on signal is input to the operation input unit 161M of the first three-input AND circuit 161. The second on operation is an operation for obtaining a state in which an on signal is input to the operation input unit 162M of the second three-input AND circuit 162. The second off operation is an operation for obtaining a state where no on signal is input to the operation input unit 162M of the second three-input AND circuit 162.

  When the operation unit 190 receives the first ON operation, an ON signal is input to the operation input unit 161M of the first three-input AND circuit 161 in a period until the operation unit 190 receives the first OFF operation. Specifically, in this period, the operation unit 190 continuously transmits an ON signal to the operation input unit 161M of the first three-input AND circuit 161.

  When the operation unit 190 accepts the first off operation, no on signal is input to the operation input unit 161M of the first three-input AND circuit 161 until the operation unit 190 accepts the first on operation. Specifically, the operation unit 190 does not transmit an ON signal to the operation input unit 161M during this period.

  When the operation unit 190 accepts the second on operation, an on signal is input to the operation input unit 162M of the second three-input AND circuit 162 until the operation unit 190 accepts the second off operation. Specifically, in this period, the operation unit 190 continuously transmits an ON signal to the operation input unit 162M of the second three-input AND circuit 162.

  When the operation unit 190 accepts the second off operation, no on signal is input to the operation input unit 162M of the second three-input AND circuit 162 until the operation unit 190 accepts the second on operation. Specifically, the operation unit 190 does not transmit an ON signal to the operation input unit 162M during this period.

  In the example of FIG. 7, the first operation switch 191 accepts a first on operation and a first off operation. The first operation switch 191 transmits an ON signal to the operation input unit 161M of the first three-input AND circuit 161. Second operation switch 192 accepts a second on operation and a second off operation. The second operation switch 192 transmits an ON signal to the operation input unit 162M of the second three-input AND circuit 162.

  In the present embodiment, the voltage of the operation input units 161M and 162M is a high level voltage during the period when the ON signal is input to the operation input units 161M and 162M. That is, the ON signal input to the operation input units 161M and 162M is a high level voltage signal. On the other hand, the voltage of the operation input units 161M and 162M is a low level voltage during a period when the ON signal is not input to the operation input units 161M and 162M. The high level voltage is higher than the low level voltage.

  The test operation is an operation for causing the leakage detection circuit 58 to perform the same operation as that at the time of leakage detection. Since the operation unit 190 can accept the test operation, it is possible to test whether or not the fuel cell power generation system 200 performs a correct operation when a leakage occurs. Specifically, when accepting a test operation, operation unit 190 transmits a test signal to leakage detection circuit 58. When the leakage detection circuit 58 receives the test signal, the leakage detection circuit 58 performs the same operation as when it detects the leakage.

  When the operation unit 190 accepts a release operation after the leakage detection circuit 58 detects a leakage, the state of the leakage detection circuit 58 returns to a state in which the leakage detection circuit 58 does not detect the leakage. Specifically, when accepting the release operation, operation unit 190 transmits a release signal to leakage detection circuit 58. When the leakage detection circuit 58 receives the release signal, the state of the leakage detection circuit 58 returns to a state where the leakage detection circuit 58 is not detecting leakage.

  In the example of FIG. 7, the earth leakage test switch 193 accepts a test operation and a release operation. The earth leakage test switch 193 transmits a test signal and a release signal.

  The operation unit 190 may be an operation unit that does not accept a test operation and a release operation. That is, the leakage test switch 193 can be omitted. The operation unit 190 may be an operation unit that accepts only one of the test operation and the release operation. Specifically, the earth leakage test switch 193 may be a switch that accepts only one of the test operation and the release operation.

  In the present embodiment, the operation unit 190 includes an operation plate, and a first operation switch 191, a second operation switch 192, and a leakage test switch 193 are provided on the operation plate. This is advantageous in terms of making these switches 191, 192 and 193 easier to handle.

  The control device 180 recognizes the occurrence of a predetermined first abnormality. Control device 180 recognizes an operation accepted by operation unit 190. Specifically, the control device 180 recognizes an operation received by the first operation switch 191. The control device 180 recognizes an operation received by the second operation switch 192. The control device 180 recognizes the operation received by the leakage test switch 193.

  In the present embodiment, the control device 180 is a microcomputer.

  In the present embodiment, power can be supplied from the power supply circuit 52 to the leakage detection circuit 58, the first three-input AND circuit 161, and the second three-input AND circuit 162. The leakage detection circuit 58, the first three-input AND circuit 161, and the second three-input AND circuit 162 can operate using this power. The power supply circuit 52 can also contribute to the generation of an ON signal that is input to the abnormality input unit 161X of the first three-input AND circuit 161.

  When the commercial power supply 15 fails, the first system power supply 11 also fails and the power supply circuit 52 cannot supply the power. However, during a power failure, the power generated by the fuel cell 41 can be supplied to the leakage detection circuit 58, the first three-input AND circuit 161, and the second three-input AND circuit 162. The leakage detection circuit 58, the first three-input AND circuit 161, and the second three-input AND circuit 162 can operate using this power. This generated power can also contribute to the generation of an ON signal that is input to the abnormality input unit 161X of the first three-input AND circuit 161.

  In the present embodiment, a voltage is supplied from the power supply circuit 52 to the abnormal input unit 161X of the first three-input AND circuit 161 via the pull-up resistor 171 so that the abnormal input unit of the first three-input AND circuit 161 is supplied. A state in which the signal input to 161X is an ON signal can be realized. The controller 180 may not be activated immediately after the fuel cell power generation system 200 is activated. However, according to the present embodiment, even when the control device 180 is not activated, a state in which the signal input to the abnormality input unit 161X of the first three-input AND circuit 161 is an on signal is realized. Thereby, even when the control device 180 is not activated, the first cutoff relay unit 31 can be turned on, and the fuel cell unit 150 and the first system power supply 11 can be connected via the first cutoff relay unit 31. Power can flow between them. For example, if the signal input to the abnormality input unit 161X of the first three-input AND circuit 161 is an ON signal, the first cutoff relay unit 31 can be turned on by performing a first ON operation.

  In FIG. 7, from the viewpoint of simplifying the drawing, a line that connects the power supply circuit 52 to the leakage detection circuit 58, the first three-input AND circuit 161, and the second three-input AND circuit 162 is not drawn. However, this does not indicate that the power supply from the power supply circuit 52 is limited to wireless power feeding. In fact, in the present embodiment, power is supplied from the power supply circuit 52 to these via a wired connection. The same applies to the power supply by the power supply circuit 52 for inputting an ON signal to the abnormality input unit 161X. The same applies to the case where power is supplied by the fuel cell 41.

(Behavior when detecting leakage)
When the fuel cell power generation system 200 detects a leakage, the leakage input unit 161L of the first three-input AND circuit 161, the leakage input unit 162L of the second three-input AND circuit 162, and the leakage input unit 163L of the two-input AND circuit 163 The input of the ON signal is stopped. Specifically, when the fuel cell power generation system 200 detects a leakage, the voltages of the leakage input portions 161L, 162L and 163L are switched from the high level voltage to the low level voltage. The high level voltage and low level voltage of the leakage input portions 161L, 162L, and 163L will be described later.

  In the present embodiment, when the leakage detection circuit 58 detects a leakage, the leakage input unit 161L of the first 3-input AND circuit 161, the leakage input unit 162L of the second 3-input AND circuit 162, and the 2-input AND circuit 163 Transmission of the ON signal to the leakage input unit 163L is stopped. Specifically, the leakage detection circuit 58 switches the voltage of the leakage input portions 161L, 162L, and 163L from the high level voltage to the low level voltage when the leakage is detected. The leakage detection circuit 58 also stops transmission of the ON signal to these when receiving the test signals. Specifically, the leakage detection circuit 58 switches the voltage of the leakage input portions 161L, 162L, and 163L from the high level voltage to the low level voltage even when the test signal is received.

  In the present embodiment, the leakage signal output unit 58L of the leakage detection circuit 58 takes charge of transmission of the ON signal to the leakage input units 161L, 162L, and 163L.

  In the present embodiment, the voltage of the leakage input portions 161L, 162L and 163L is a high level voltage during the period when the ON signal is input to the leakage input portions 161L, 162L and 163L. That is, the ON signal input to leakage input portions 161L, 162L, and 163L is a high-level voltage signal. On the other hand, during the period when no ON signal is input to leakage input portions 161L, 162L, and 163L, the voltages of leakage input portions 161L, 162L, and 163L are low level voltages. The high level voltage is higher than the low level voltage.

  In the present embodiment, the same signal as the signal input to the leakage input portions 161L, 162L and 163L is also input to the third cutoff relay portion 33. Specifically, the leakage detection circuit 58 transmits the same signal as the signal transmitted to the leakage input units 161L, 162L, and 163L to the third cutoff relay unit 33. More specifically, the voltage of the receiving unit of the third cutoff relay unit 33 is the same as the leakage input units 161L, 162L, and 163L. The 3rd interruption relay part 33 switches from an ON state to an OFF state at the timing when the input of the ON signal to self was stopped. Specifically, the third cutoff relay unit 33 switches from the on state to the off state at the timing when the voltage of its own receiving unit switches from the high level voltage to the low level voltage.

  In the present embodiment, the third cutoff relay unit 33 switches from the off state to the on state when the operation unit 190 accepts the release operation. In addition, the fuel cell power generation system 200 of the present embodiment is configured such that when the control power supply 47 is activated, the third cutoff relay unit 33 is switched from the off state to the on state.

(Behavior when an abnormality occurs)
When the fuel cell power generation system 200 detects a predetermined first abnormality, the controller 180 turns on the abnormality input unit 161X of the first three-input AND circuit 161 and the abnormality input unit 162X of the second three-input AND circuit 162. The signal input is stopped. Specifically, when the fuel cell power generation system 200 detects a predetermined first abnormality, the voltage of the abnormality input units 161X and 162X is switched from the high level voltage to the low level voltage by the control device 180. The high level voltage and low level voltage of the abnormality input units 161X and 162X will be described later.

  In the present embodiment, the control device 180 operates so that the ON signal is not input to the abnormality input units 161X and 162X during the period in which the first abnormality is detected.

  Specifically, in the present embodiment, as described above, the voltage is supplied from the power supply circuit 52 to the abnormal input unit 161X of the first three-input AND circuit 161 through the pull-up resistor 171. A state can be realized in which the signal input to the abnormal input unit 161X of the first three-input AND circuit 161 is an ON signal. However, when the first abnormality is detected, control device 180 outputs an off signal. This off signal cancels the voltage of the abnormal input portion 161X derived from the power supply circuit 52. Specifically, the off signal fixes the voltage of the abnormal input unit 161X to a low level voltage. As a result, the state where the ON signal is input to the abnormality input unit 161X is released. In this way, the control device 180 stops the input of the ON signal to the abnormality input unit 161X of the first three-input AND circuit 161. During the period in which the first abnormality is detected, control device 180 continuously outputs the off signal. As a result, the voltage of the abnormal input unit 161X derived from the power supply circuit 52 is continuously canceled (specifically, the voltage of the abnormal input unit 161X is fixed to a low level voltage), and no ON signal is input to the abnormal input unit 161X. The state continues. On the other hand, the control device 180 maintains the state in which the voltage of the abnormal input unit 161X derived from the power supply circuit 52 is continuously supplied by not outputting the off signal. Thereby, the state in which the ON signal is input to the abnormality input unit 161X is maintained. In the present embodiment, the output of the off signal is performed by the first off signal output unit 181 of the control device 180.

  In the present embodiment, the off signal is an electric signal whose logic is inverted from that of the abnormal input portion 161X derived from the power supply circuit 52. The amplitude of the electrical signal can be the same as the amplitude of the electrical signal of the abnormal input unit 161X derived from the power supply circuit 52.

  Further, the control device 180 can continuously transmit an ON signal to the abnormality input unit 162X of the second three-input AND circuit 162. When the first abnormality is detected, the control device 180 stops transmission of the ON signal to the abnormality input unit 162X. Specifically, when the first abnormality is detected, the control device 180 switches the voltage of the abnormality input unit 162X from the high level voltage to the low level voltage. In the present embodiment, transmission of the ON signal to the abnormality input unit 162X is performed by the second OFF signal output unit 182 of the control device 180.

  In the present embodiment, the voltages of the abnormal input portions 161X and 162X are high level voltages during the period when the ON signal is input to the abnormal input portions 161X and 162X. That is, the ON signal input to the abnormality input units 161X and 162X is a high level voltage signal. On the other hand, during the period when the ON signal is not input to the abnormal input portions 161X and 162X, the voltages of the abnormal input portions 161X and 162X are low level voltages. The high level voltage is higher than the low level voltage.

  The control device 180 may be configured to recognize not only the predetermined first abnormality but also the occurrence of the predetermined second abnormality, and perform the same operation as when the first abnormality occurs when the second abnormality occurs. When generalized, the control device 180 may be configured to recognize a plurality of abnormalities including the first abnormality and perform an operation similar to that at the time of occurrence of the first abnormality when at least one of the plurality of abnormalities occurs. .

  The first abnormality may be an overcurrent in the fuel cell power generation system 200 or an abnormality in the voltage of the commercial power supply 15. The voltage abnormality may be a voltage frequency abnormality or a voltage amplitude abnormality. The abnormality of the voltage frequency indicates, for example, that the voltage frequency is lower than the lower limit threshold or that the voltage frequency is higher than the upper limit threshold. An abnormal voltage amplitude indicates, for example, that the frequency of the voltage is lower than the lower limit threshold or that the frequency of the voltage is higher than the upper limit threshold. The same applies to the second abnormality. The same applies to the plurality of abnormalities.

  The overcurrent in the fuel cell power generation system 200 can be detected by providing an overcurrent relay in the fuel cell power generation system 200, for example. An abnormality in the voltage of the commercial power supply 15 can be detected by, for example, the power recovery detection circuit 71.

(Behavior when power failure occurs)
In the present embodiment, the fuel cell power generation system 200 can detect that the commercial power supply 15 has failed. Specifically, the fuel cell power generation system 200 can detect that the voltage supply from the second power supply 12 to the second connection path 142 is lost. When this detection is performed, the control device 180 stops the input of the ON signal to the abnormality input unit 162X of the second three-input AND circuit 162. Specifically, when this detection is made, the control device 180 switches the voltage of the abnormality input unit 162X from the high level voltage to the low level voltage. Thereby, the 2nd interruption | blocking relay part 32 switches from an ON state to an OFF state.

  Specifically, the power recovery detection circuit 71 can detect that the voltage supply from the second system power supply 12 to the second connection path 142 is lost. When the power recovery detection circuit 71 performs this detection, the power recovery detection circuit 71 stops transmitting the ON signal to the power recovery input unit 163R of the 2-input AND circuit 163. Specifically, when the power recovery detection circuit 71 performs this detection, the power recovery input circuit 163R fixes the voltage of the power recovery input unit 163R to a low level voltage. When the voltage of the power recovery input unit 163R is fixed at the low level voltage, the 2-input AND circuit 163 stops transmitting the voltage supply detection signal to the control device 180. The control device 180 can determine that the second system power supply 12 has failed due to not receiving the voltage supply detection signal. When this determination is made, the control device 180 operates so that the input of the ON signal to the abnormal input unit 162X of the second three-input AND circuit 162 is stopped. Specifically, when this determination is made, control device 180 stops transmission of the ON signal to abnormality input unit 162X. More specifically, when this determination is made, the control device 180 fixes the voltage of the abnormal input unit 162X to a low level voltage. Thereby, the 2nd interruption | blocking relay part 32 switches from an ON state to an OFF state.

(Behavior at the start of autonomous operation)
The fuel cell power generation system 200 of the present embodiment is configured to start a self-sustained operation after a power failure occurs. Specifically, after the second interrupting relay unit 32 is interrupted with the occurrence of a power failure, the first interrupting relay unit 31 is interrupted. Next, the second switching relay unit 39 is switched so that the fuel cell 41 is electrically connected to the third cutoff relay unit 33. In this way, the connection state shown in FIG. 4 is obtained. Thereafter, power supply from the fuel cell 41 to the backup boiler 27 and the outlet 26 is started. The method of blocking the first blocking relay unit 31 is the same as the method of blocking the first blocking relay unit 31 when the first abnormality occurs. Specifically, as in the case of the occurrence of the first abnormality, the control device 180 cancels the state where the ON signal is input to the abnormality input unit 161X of the first three-input AND circuit 161.

(Behavior during voltage supply from second system power supply 12 to second connection path 142)
When the fuel cell power generation system 200 detects voltage supply from the second system power supply 12 to the second connection path 142, an ON signal is input to the power recovery input unit 163R of the 2-input AND circuit 163.

  In the present embodiment, the power recovery detection circuit 71 transmits an ON signal to the power recovery input unit 163 </ b> R of the 2-input AND circuit 163 when detecting the voltage supply from the second system power supply 12 to the second path 92.

  Specifically, the power recovery detection circuit 71 continuously transmits an ON signal to the power recovery input unit 163R during a period in which the power recovery detection circuit 71 detects voltage supply from the second system power supply 12 to the second path 92. . On the other hand, the power recovery detection circuit 71 does not transmit an ON signal to the power recovery input unit 163R in a period in which the power recovery detection circuit 71 does not detect the voltage supply.

  In the present embodiment, the voltage of the power recovery input unit 163R is a repetitive pulse voltage during the period when the ON signal is input to the power recovery input unit 163R. That is, the ON signal input to the power recovery input unit 163R is a repetitive pulse voltage signal. On the other hand, the voltage of the power recovery input unit 163R is a low level voltage during a period when no ON signal is input to the power recovery input unit 163R. The repetitive pulse voltage is a voltage that exhibits a repetitive pulse waveform. The repetitive pulse waveform is a waveform in which a period in which the voltage is at a low level and a period in which the voltage is at a high level voltage appear alternately. The high level voltage is higher than the low level voltage.

(Signals output from the AND circuits 161, 162 and 163)
As described above, in the present embodiment, the voltages of the leakage input units 161L, 162L, and 163L, the operation input units 161M and 162M, the abnormal input units 161X and 162X, and the power recovery input unit 163R are high-level voltages or It can be a low level voltage.

  During a period in which the high level voltage is supplied to the three input units of the leakage input unit 161L, the operation input unit 161M, and the abnormal input unit 161X, the voltage of the output unit of the first three-input AND circuit 161 is a high level voltage. is there. The high level voltage of the output unit is supplied to the first cutoff relay unit 31. Thus, the high level voltage supplied to the first cutoff relay unit 31 functions as a signal for turning on the first cutoff relay unit 31. On the other hand, during a period in which at least one voltage of the three input parts 161L, 161X and 161M is a low level voltage, the voltage of the output part of the first three-input AND circuit 161 is a low level voltage. This low level voltage cannot turn on the first cutoff relay unit 31.

  During the period when the high level voltage is supplied to the three input units of the leakage input unit 162L, the operation input unit 162M, and the abnormal input unit 162X, the voltage of the output unit of the second three-input AND circuit 162 is a high level voltage. is there. The high level voltage of the output unit is supplied to the second cutoff relay unit 32. The high level voltage supplied to the second cutoff relay unit 32 in this manner functions as a signal for turning on the second cutoff relay unit 32. On the other hand, during a period in which at least one voltage of the three input parts 162L, 162X and 162M is a low level voltage, the voltage of the output part of the second three-input AND circuit 162 is a low level voltage. This low level voltage cannot turn on the second cutoff relay unit 32.

  During the period when the high level voltage is supplied to the leakage input unit 163L and the repetitive pulse voltage is supplied to the power recovery input unit 163R, the voltage of the output unit of the 2-input AND circuit 163 is the repetitive pulse voltage. The repetitive pulse voltage of the output unit is supplied to the control device 180. That is, the voltage supply detection signal is a repetitive pulse voltage signal. On the other hand, during the period when the voltage of the leakage input unit 163L and / or the power recovery input unit 163R is the low level voltage, the voltage of the output unit of the 2-input AND circuit 163 is the low level voltage.

(Functions of cutoff relay units 31 and 32)
As can be understood from the above description, according to the present embodiment, the first interrupting relay unit 31 and the leakage current, the occurrence of a predetermined abnormality such as an overcurrent, and the external operation by a person, The 2nd interruption | blocking relay part 32 can be interrupted | blocked. Thus, according to the present embodiment, the multifunctional cutoff relay units 31 and 32 are realized. Specifically, the first interrupting relay unit 31 and the second interrupting relay unit 32 can be interrupted by the contribution of the leakage detection circuit 58. With the contribution of the control device 180, the first cutoff relay unit 31 and the second cutoff relay unit 32 can be cut off when the first abnormality occurs. Due to the contribution of the operation unit 190, the first cutoff relay unit 31 and the second cutoff relay unit 32 can be blocked during an external operation by a person.

(Output of electric power from the fuel cell unit 150)
The fact that the three output conditions of the first output condition, the second output condition, and the third output condition are satisfied means that the control device 180 permits the power supply from the fuel cell unit 150 to the second connection path 142. It is a necessary condition. That is, at least during the period in which these three output conditions are satisfied, the control device 180 permits power supply from the fuel cell unit 150 to the second connection path 142. On the other hand, the control device 180 prohibits power supply from the fuel cell unit 150 to the second connection path 142 during a period in which even one of these three output conditions is not satisfied. The first output condition is a condition that an ON signal is input to the operation input unit 162M of the second three-input AND circuit 162. The second output condition is a condition that the fuel cell power generation system 200 does not detect the first abnormality. The third output condition is a condition that the control device 180 is receiving a voltage supply detection signal.

  Assume that the third output condition is a condition that the fuel cell power generation system 200 detects the voltage supply from the second system power supply 12 to the second connection path 142. In that case, even if the first output condition, the second output condition, and the third output condition are satisfied, if the second cutoff relay unit 32 is in an OFF state due to electric leakage, the fuel from the second system power supply 12 No voltage is supplied to the battery unit 150. That is, in this case, there is a possibility that the generated power of the fuel cell unit 150 is output to the second connection path 142 even though no voltage is supplied from the second power supply 12 to the fuel cell unit 150. On the other hand, in the present embodiment, the third output condition is a condition that the control device 180 receives the voltage supply detection signal. Combining the first and second output conditions with the third output condition means that the voltage is supplied from the second system power supply 12 to the second connection path 142 and the second cutoff relay unit 32 is in the ON state. Sometimes, it is advantageous from the viewpoint of outputting the power generated by the fuel cell unit 150 to the second connection path 142. This embodiment is suitable for starting the supply of the generated power of the fuel cell unit 150 to the second connection path 142 when a voltage is supplied from the second system power supply 12 to the fuel cell unit 150. The ability to start the supply of generated power at such a time means that the supply of generated power can be started in a state where there is a reference for the voltage of the second system power supply 12. As a result, the fuel cell unit 150 can output a current in phase with the reference voltage, and the fuel cell 41 can appropriately operate as a grid interconnection device. In addition, the grid connection regulation stipulates that the power cell be disconnected at the time of a power failure. In this sense, when the voltage is supplied to the fuel cell unit 150, the generated power of the fuel cell unit 150 is connected to the second connection path 142. It is appropriate to start the supply.

  In the present embodiment, the control device 180 can recognize an operation received by the operation unit 190. Therefore, the control device 180 can grasp whether or not the first output condition, that is, the condition that the ON signal is input to the operation input unit 162M of the second three-input AND circuit 162 is satisfied.

  The permission and prohibition of power supply from the fuel cell unit 150 to the second connection path 142 can be performed using the DCAC inverter 43. In the present embodiment, when supplying power from the fuel cell unit 150 to the second connection path 142, the DCAC inverter 43 performs power conversion for converting DC power generated by the fuel cell unit 150 into AC power. That the three output conditions of the first output condition, the second output condition, and the third output condition are satisfied is a necessary condition for the control device 180 to cause the DCAC inverter 43 to perform the power conversion. That is, at least during the period when these three output conditions are satisfied, the control device 180 causes the DCAC inverter 43 to perform the power conversion. On the other hand, in a period in which even one of these three output conditions is not satisfied, control device 180 does not cause DCAC inverter 43 to perform the power conversion. In this way, the control device 180 can permit or prohibit the output of power from the DCAC inverter 43 by permitting or prohibiting the power conversion of the DCAC inverter 43. For this reason, permission of power supply from the fuel cell unit 150 to the second connection path 142 can be appropriately performed.

  When the fuel cell 41 is generating power during the period in which the above three output conditions are satisfied, a configuration in which the generated power is output from the fuel cell unit 150 to the second connection path 142 can be employed. . Specifically, in the embodiment, when the fuel cell 41 is generating power during the period in which the above three output conditions are satisfied, the DC generated power is converted into AC power by the DCAC inverter 43. After that, it is output to the second connection path 142.

  As described above, the control device 180 is configured to recognize a plurality of abnormalities including the first abnormality and perform the same operation as that at the time of occurrence of the first abnormality when at least one of the plurality of abnormalities occurs. May be. In that case, in addition to the first to third conditions, it is necessary that the condition that the fuel cell power generation system 200 does not detect any abnormality other than the first abnormality in the plurality of abnormalities is satisfied. It is a condition. Of course, an aspect in which the above-mentioned necessary condition is that other conditions are satisfied in addition to the first to third conditions may be employed. Specifically, in the present embodiment, the other condition is a condition that the fuel cell power generation system 200 does not detect that the commercial power supply 15 has failed.

(Startup mode of fuel cell power generation system 200)
The operation mode that can be adopted by the fuel cell power generation system 200 has a startup mode. Hereinafter, the startup mode of the fuel cell power generation system 200 will be described. In the following example, before the start-up mode is started, the interrupting relay units 31, 32, and 33 are in the off state.

  In the start-up mode, the state where the signal input to the abnormal input unit 162 of the second three-input AND circuit 162 is an ON signal is as follows.

  A voltage is supplied from the power supply circuit 52 to the abnormal input unit 161X of the first three-input AND circuit 161 via the pull-up resistor 171 and is input to the abnormal input unit 161X of the first three-input AND circuit 161. The signal is kept on. When the operation unit 190 accepts the first ON operation while the signal input to the abnormality input unit 161X of the first three-input AND circuit 161 is maintained as the ON signal, the first cutoff relay unit 31 is turned on from the OFF state. Switch to state. When the first cutoff relay unit 31 is switched from the off state to the on state, electric power is supplied from the first system power supply 11 to the control power source 47 of the fuel cell unit 150 via the first cutoff relay unit 31. When power is supplied to the control power supply 47, the control power supply 47 is activated. After the control power supply 47 is activated, power is supplied from the control power supply 47 to the control device 180. When power is supplied from the control power supply 47 to the control device 180, the control device 180 is activated. After the control device 180 is started, the control device 180 maintains the signal input to the abnormal input unit 162X of the second three-input AND circuit 162 as an on signal.

  According to the activation mode, the control device 180 can be activated appropriately. Further, after this activation, the control device 180 can maintain the signal input to the abnormal input section 162X of the second three-input AND circuit 162 as an ON signal. When the second on operation is performed on the operation unit 190 in the state in which the maintenance is performed, the second cutoff relay unit 182 can be switched from the off state to the on state. As a result, it is possible to supply a voltage from the second system power supply 12 to the fuel cell unit 150 via the second cutoff relay unit 182.

  In the activation mode of the present embodiment, the third cutoff relay unit 33 is switched from the off state to the on state when the control power supply 47 is activated.

(First specific example of switching of interrupting relay units 31, 32 and 33)
Hereinafter, a first specific example of switching of the interrupting relay units 31, 32, and 33 will be described.

  In the first specific example, in the initial state, the interrupting relay units 31, 32, and 33 are in the off state.

  When in the initial state, the operation unit 190 accepts the first on operation, the first cutoff relay unit 31 is switched from the off state to the on state. Further, when the first cutoff relay unit 31 is switched to the ON state, power is supplied to the control power supply 47 of the fuel cell unit 150, the control power supply 47 is activated, and the third cutoff relay unit 33 is activated when the control power supply 47 is activated. Switch to the on state. Thereby, the state A1 is obtained.

  When in the state A1, when the operation unit 190 accepts the second on operation, the second cutoff relay unit 32 is switched from the off state to the on state. Thereby, the state B1 is obtained.

  When the leakage detection circuit 58 detects a leakage in the state B1, the first cutoff relay unit 31, the second cutoff relay unit 32, and the third cutoff relay unit 33 are switched from the on state to the off state. Thereby, the state C1 is obtained.

  When in the state C1, the operation unit 190 receives a release operation, the first cutoff relay unit 31, the second cutoff relay unit 32, and the third cutoff relay unit 33 are switched from the off state to the on state. Thereby, the state D1 is obtained.

  When the operation unit 190 accepts the second off operation while in the state D1, the second cutoff relay unit 32 switches from the on state to the off state. Thereby, the state E1 is obtained.

  When in the state E1, the operation unit 190 accepts the first off operation, the first cutoff relay unit 31 is switched from the on state to the off state. Thereby, the state F1 is obtained.

  Table 1 summarizes the state of switching from the initial state to the state F1 sequentially. “ON” in Table 1 corresponds to the on state, and “OFF” corresponds to the off state.

(Second specific example of switching of the interrupting relay units 31, 32 and 33)
Hereinafter, a second specific example of switching of the interrupting relay units 31, 32, and 33 will be described.

  In the second specific example, in the initial state, the first cutoff relay unit 31 and the second cutoff relay unit 32 are in the off state, the third cutoff relay unit 33 is in the on state, and the self-sustaining operation shown in FIG. 4 is performed. ing.

  When the leakage detection circuit 58 detects leakage in the initial state, the third cutoff relay unit 33 is switched from the on state to the off state. Thereby, the state A2 is obtained.

  When in the state A2, when the operation unit 190 receives a release operation, the third cutoff relay unit 33 is switched from the off state to the on state. Thereby, the state B2 is obtained.

  Table 2 summarizes the state of switching sequentially from the initial state to the state B2. “ON” in Table 2 corresponds to the on state, and “OFF” corresponds to the off state.

  According to the technology according to the present disclosure, the function of interrupting the first and second interrupting relay units when the electric leakage occurs and the function for another fuel cell power generation system can coexist. The fuel cell power generation system according to the present disclosure is advantageous in cost.

11, 12, 15 Power supply 16U, 16O, 16W Line 17 Distribution board 19 Auxiliary power supply device 21a Igniter 21b, 25 Heater 22 ACDC converter 26 Outlet 27 Backup boiler 31, 32, 33, 34, 38, 39 Relay unit 41 Fuel cell 42 DCDC converter 43 DCAC inverter 44 Auxiliary machine 45 Reformer 46 Combustor 47 Control power supply 51 Leakage detection element 51p Leakage detection position 52 Power supply circuit 52a Primary side part 52b Secondary side part 53 Insulation transformer 53a Primary side winding 53b Secondary winding 54 Rectifier circuit 55 Capacitor 55m, 55n End 56 Diode 56a Anode 56c Cathode 58 Leakage detection circuit 58L Leakage signal output unit 61, 62, 63, 64 Connection unit 71 Power recovery detection circuit 80, 81, 82 Substrate 91 , 92, 93, 141, 14 Path 100 Power supply circuit 150 Fuel cell unit 161, 162, 163 AND circuit 161L, 162L, 163L Leakage input unit 161M, 162M Operation input unit 161X, 162X Abnormal input unit 163R Power recovery input unit 171 Pull-up resistor 180 Controller 181 182 OFF signal output unit 190 operation unit 191, 192, 193 switch 199 switching device 200 fuel cell power generation system

Claims (7)

A fuel cell power generation system connected to a first system power source using a first connection path and connected to a second system power source using a second connection path,
A first interrupting relay section provided on the first connection path;
A second cutoff relay provided on the second connection path;
A fuel cell unit connected to the first system power supply using the first connection path and connected to the second system power supply using the second connection path;
The first interrupting relay has a three-input section, that is, an earth leakage input section, an abnormal input section, and an operation input section, and the first on-state relay is satisfied in a period in which a first on-condition that an on signal is inputted to these three input sections is satisfied. A first three-input AND circuit that maintains the first interrupting relay unit in an off state during a period when the first on condition is not satisfied,
The second interrupting relay has a three-input section including an earth leakage input section, an abnormal input section, and an operation input section, and the second on-state relay is in a period in which a second on-condition is established that an on signal is input to the three input sections. A second three-input AND circuit that maintains the second cut-off relay unit in an off state during a period when the second on-condition is not satisfied,
A first ON operation for obtaining a state in which an ON signal is input to the operation input unit of the first three-input AND circuit, and an ON signal is input to the operation input unit of the first three-input AND circuit A first off operation for obtaining a non-existing state, a second on operation for obtaining a state in which an on signal is input to the operation input section of the second three-input AND circuit, and the second three-input AND A second off operation for obtaining a state in which no on signal is input to the operation input unit of the circuit;
A control device for recognizing an operation received by the operation unit and occurrence of a predetermined first abnormality;
The control device is configured to provide a voltage supply detection signal in a period in which a third on-condition is established in which an on-signal is input to the two input units, the earth leakage input unit and the power recovery input unit. And a two-input AND circuit that does not transmit the voltage supply detection signal to the control device in a period in which the third ON condition is not satisfied,
When the fuel cell power generation system detects a leakage, an ON signal to the leakage input section of the first three-input AND circuit, the leakage input section of the second three-input AND circuit, and the leakage input section of the two-input AND circuit Is stopped,
When the fuel cell power generation system detects the first abnormality, the control device inputs an ON signal to the abnormality input unit of the first three-input AND circuit and the abnormality input unit of the second three-input AND circuit. Is stopped,
When the fuel cell power generation system detects voltage supply from the second power supply to the second connection path, an ON signal is input to the power recovery input unit of the two-input AND circuit,
The fact that the first output condition, the second output condition, and the third output condition are satisfied is a necessary condition for the control device to permit power supply from the fuel cell unit to the second connection path,
The first output condition is a condition that an ON signal is input to the operation input unit of the second three-input AND circuit,
The second output condition is a condition that the fuel cell power generation system does not detect the first abnormality,
The fuel cell power generation system, wherein the third output condition is a condition that the control device receives the voltage supply detection signal. The first system power source and the second system power source are power sources using a commercial power source as a power supply source,
The fuel cell power generation system according to claim 1, wherein the first abnormality is an overcurrent in the fuel cell power generation system or a voltage abnormality of the commercial power supply. The fuel cell unit further includes a DCAC inverter,
The DCAC inverter performs power conversion to convert DC power generated by the fuel cell unit into AC power when supplying power from the fuel cell unit to the second connection path,
The requirement that the control device cause the DCAC inverter to perform the power conversion is that the first output condition, the second output condition, and the third output condition are satisfied. 2. The fuel cell power generation system according to 2. The fuel cell power generation system further includes a power supply circuit and a pull-up resistor,
The power supply circuit is provided at a position where power is supplied from the first system power supply and / or the second system power supply even when the first cutoff relay unit and the second cutoff relay unit are in an off state,
When a voltage is supplied from the power supply circuit to the abnormal input section of the first three-input AND circuit via the pull-up resistor, a signal input to the abnormal input section of the first three-input AND circuit is The fuel cell power generation system according to any one of claims 1 to 3, wherein a state that is an ON signal is realized.   The said 1st connection path | route has a system | strain side part which connects a said 1st interruption | blocking relay and a said 1st system power supply, and electric power is supplied to the said power supply circuit from the said system | strain side part. Fuel cell power generation system. The fuel cell unit has a control power source,
The operation mode of the fuel cell power generation system has a startup mode,
In the startup mode,
When a voltage is supplied from the power supply circuit to the abnormal input section of the first three-input AND circuit via the pull-up resistor, a signal input to the abnormal input section of the first three-input AND circuit is Maintained on signal,
When the operation unit receives the first on operation while the signal input to the abnormal input unit of the first three-input AND circuit is maintained as an on signal, the first cutoff relay unit is turned on from the off state. Switch to the state,
When the first cutoff relay unit is switched from the off state to the on state, power is supplied from the first system power source to the control power source via the first cutoff relay unit,
When power is supplied to the control power supply, the control power supply is activated,
After the control power supply is activated, power is supplied from the control power supply to the control device,
When the control power is supplied from the control power source to the control device, the control device is activated,
6. The fuel cell power generation system according to claim 4, wherein after the control device is activated, the control device maintains an on signal as a signal input to the abnormality input unit of the second three-input AND circuit. The fuel cell power generation system further includes a leakage detection element disposed at a leakage detection position,
A first path used to guide power from the first system power supply to the first load through the first interrupting relay unit and the leakage detection position in this order;
A second path used to guide power from the second system power supply to the second load through the second interruption relay unit and the leakage detection position in this order, and
The fuel leakage power generation system according to any one of claims 1 to 6, wherein the leakage detection element is commonly used for leakage detection of the first load and leakage detection of the second load.

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