Power supply relay device and distributed power supply system

Abstract

To provide a power supply repeating device which can effectively use a device having a power supply function.SOLUTION: A power supply repeating device comprises: a power input terminal 21 in which power is input; a power output terminal 22 which outputs the power; a power conversion circuit 23 which is connected between the power input terminal 21 and the power output terminal 22, and performs power conversion processing for converting the power input to the power input terminal 21 into predetermined power and then outputting the converted power to the power output terminal 22; a detection terminal which is connected with an external power detection part 19; and a circuit control unit 25 which controls an operation of the power conversion circuit 23. The circuit control unit 25 is constituted not to perform the power conversion processing in the power conversion circuit 23 when a predetermined processing execution condition including at least a condition regarding whether or not power is supplied to the power detection part 19 is not satisfied, and to perform the power conversion processing in the power conversion circuit 23 when the processing execution condition is satisfied and there is input voltage in the power input terminal 21.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power supply relay device that relays the supply of power from a power input terminal to a power output terminal and a distributed power system.

Background Art

[0002] Patent Document 1 (Japanese Patent No. 6289661) describes a distributed power system including a solar cell, a storage battery, and a power generation device. In this distributed power system, during grid-connected operation in which power supply from the power grid is being normally performed, the power generation device is configured to generate power while the current sensor (40) detects the forward power flow. That is, the generated power of the power generation device is limited to less than the power consumption of the load. Further, in this distributed power system, during off-grid operation in which power supply from the power grid is not being normally performed, the surplus power of the power generation device can be charged into the storage battery through a path that does not pass through the current sensor (40). Thus, in the distributed power system described in Patent Document 1, in order to sufficiently secure the remaining charge amount of the storage battery during off-grid operation, in addition to the solar cell, a stationary power generation device is required.

[0003] Patent Document 2 (Japanese Patent No. 6351351) describes a distributed power system to which a storage battery of an electric vehicle can be connected. While the storage battery of the electric vehicle is connected to the distributed power system, AC power from the commercial power system side can be converted into DC power to charge the storage battery of the electric vehicle, and DC power from the storage battery of the electric vehicle can be converted into AC power and output to the residential side. Thus, in the distributed power system described in Patent Document 2, power can be supplied from the storage battery of the electric vehicle when power is required.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Although the V2H (Vehicle to Home) system as described in Patent Document 2 is convenient, there is a problem that the device for connecting an electric vehicle and a distributed power system becomes expensive.

[0006] In addition to electric vehicles, fuel cell vehicles, plug-in hybrid vehicles, etc., there are also many vehicles equipped with electrical outlets capable of outputting AC power. Furthermore, there are also many portable power generation devices and power storage devices equipped with electrical outlets capable of outputting AC power. Therefore, when the distributed power system is short of power, it is preferable that AC power can be supplied from these vehicles and devices.

[0007] The present invention has been made in view of the above problems, and an object thereof is to provide a power supply relay device and a distributed power system that can effectively utilize a device having a power supply function.

Means for Solving the Problems

[0008] The characteristic configuration of the power supply relay device according to the present invention for achieving the above object is a power input terminal to which power is input, a power output terminal that outputs power, a power conversion circuit connected between the power input terminal and the power output terminal, which performs a power conversion process of converting the power input to the power input terminal into a predetermined power and then outputting it to the power output terminal, a detection terminal connected to an external power detection part, and a circuit control part that controls the operation of the power conversion circuit based on the input power to the detection terminal. The power detection part supplies power when the power supply from the power system is normal, and does not supply power when the power supply from the power system is not normal. It has a first detection part, and a second detection part that does not supply power when the power supply from the power system is normal and can be supplied with power from another power source when the power supply from the power system is not normal. The circuit control part As a condition to be satisfied, from the state where the power conversion process in the power conversion circuit is not performed and power is supplied to at least one of the first detection part and the second detection part, it is shifted to the state where the power conversion process in the power conversion circuit is not performed and power is not supplied to both the first detection part and the second detection part. When a predetermined processing execution condition including is not satisfied, the power conversion processing in the power conversion circuit is not performed, and when the processing execution condition is satisfied and there is an input voltage at the power input terminal, the power conversion processing in the power conversion circuit is performed.

[0009] According to the above characteristic configuration, when a device having a power supply function is connected to the power input terminal, the power supply relay device can convert the power input to the power input terminal into a predetermined power by the power conversion circuit and then supply it to the power output terminal. At this time, even if a device having a power supply function is connected to the power input terminal, the circuit control unit does not perform the power conversion processing in the power conversion circuit when the processing execution condition is not satisfied, and performs the power conversion processing in the power conversion circuit when the processing execution condition is satisfied. That is, only when a device having a power supply function is connected to the power input terminal and power supply is required from the device having a power supply function, the power input to the power input terminal can be converted into a predetermined power by the power conversion circuit and then supplied to the power output terminal. In addition, according to this characteristic configuration, when shifting from the state where either the power supply from the power system capable of supplying power to the first detection part or the power supply by independently operating a distributed power source or the like capable of supplying power to the second detection part is being performed, to the state where neither the power supply from the power system nor the power supply by independently operating the distributed power source is being performed, that is, when there is no power source other than the device having the power supply function connected to the power input terminal, the power input to the power input terminal can be converted into a predetermined power by the power conversion circuit and then supplied to the power output terminal. In addition, it is guaranteed that the power supplied from the device having the power supply function does not flow back to the power system. On the other hand, even if a device having a power supply function is connected to the power input terminal, the circuit control unit does not perform the power conversion process in the power conversion circuit when either the power supply from the power system capable of supplying power to the first detection part or the power supply by independently operating a distributed power source or the like capable of supplying power to the second detection part is being performed. That is, it is possible to prevent the power input from the device having the power supply function to the power input terminal from being wasted. Therefore, a power supply relay device that can effectively utilize a device having a power supply function can be provided.

[0014] Another characteristic configuration of the power supply relay device according to the present invention is that the processing execution condition includes that the current time is in a predetermined processing execution time zone in which the power conversion processing is allowed to be performed as a condition to be satisfied.

[0015] According to the above characteristic configuration, when a device having a power supply function is connected to the power input terminal and the current time is in a predetermined processing execution time zone in which the power conversion processing is allowed to be performed, the circuit control unit converts the power input to the power input terminal into a predetermined power by the power conversion circuit and then supplies it to the power output terminal. That is, by determining a time zone in advance, the power input from the device having a power supply function to the power input terminal can be effectively utilized. On the other hand, even if a device having a power supply function is connected to the power input terminal, when the current time is not within a predetermined processing execution time zone where power conversion processing is permitted, the circuit control unit does not perform power conversion processing in the power conversion circuit. That is, it is possible to prevent wasteful consumption of the power input from the device having the power supply function to the power input terminal.

[0016] Still another characteristic configuration of the power supply relay device according to the present invention is a power generation input terminal to which a power generation device is connected, When the power supply to the power detection part is being normally performed, the power output terminal is connected to the power generation input terminal and the power output terminal is not connected to the power conversion circuit, and when the power supply to the power detection part is not being normally performed, a switching part that connects the power output terminal to the power conversion circuit.

[0017] According to the above characteristic configuration, it is possible to switch between a state in which the power input to the power input terminal is output to the power output terminal and a state in which the power input to the power generation input terminal is output to the power output terminal.

[0018] A characteristic configuration of the distributed power supply system according to the present invention is the above power supply relay device, a distributed power source, a power conditioner to which the power output terminals of the distributed power source and the power supply relay device are connected, and when the power supply from the power grid is being normally performed, power can be supplied from at least one of the power grid and the power conditioner, and when the power supply from the power grid is not being normally performed, a power line that can receive power supply from the power conditioner.

[0019] According to the above characteristic configuration, a distributed power supply system including a power supply relay device, a distributed power source, a power conditioner, and a power line can be realized.

[0020] Another characteristic configuration of the distributed power system according to the present invention is that the power supply relay device supplies the power supplied from the power line through a power receiving line connected to the power line to a power supply terminal attachable to a power supply target device in a power supply state, and switches to a non-power supply state in which the power is not supplied to the power supply terminal. It is provided with a power supply changeover switch, and a switch control unit that switches the power supply changeover switch to the power supply state when a predetermined power supply execution condition is satisfied, and switches the power supply changeover switch to the non-power supply state when the power supply execution condition is not satisfied.

[0021] According to the above characteristic configuration, when a power supply target device is attached to the power supply terminal of the power supply relay device and a predetermined power supply execution condition is satisfied, the power supply relay device can supply the power supplied from the power line to the power supply target device through the power receiving line connected to the power line.

[0022] Yet another characteristic configuration of the distributed power system according to the present invention is that the power supply execution condition includes, as a requirement to be satisfied, that the current time is within a predetermined power supply execution time zone in which power supply to the power supply terminal is permitted.

[0023] According to the above characteristic configuration, when a power supply target device is attached to the power supply terminal of the power supply relay device and the current time is within a predetermined power supply execution time zone in which power supply to the power supply terminal is permitted, the power supply relay device can supply the power supplied from the power line to the power supply target device through the power receiving line connected to the power line.

[0024] Yet another characteristic configuration of the distributed power system according to the present invention is that the power detection part is a part where power is supplied when the power supply from the power system is being performed normally, and no power is supplied when the power supply from the power system is not being performed normally. The power supply execution condition includes, as a requirement to be satisfied, that no power supply is being performed to the power detection part.

[0025] According to the above characteristic configuration, in the power supply relay device, a power supply target device is attached to the power supply terminal. In the case of a power outage, for example, when the power supply from the power grid to the power detection part is not being carried out normally, the power supply target device can be supplied with power from the power grid via the power receiving line connected to the power line.

[0026] Yet another characteristic configuration of the distributed power supply system according to the present invention is that the distributed power supply has a charge and discharge device, The power supply execution conditions include, as a requirement to be satisfied, that the remaining charge amount of the charge and discharge device is equal to or greater than a predetermined value.

[0027] According to the above characteristic configuration, in a distributed power supply system provided with a charge and discharge device as a distributed power supply, when the remaining charge amount of the charge and discharge device is equal to or greater than a predetermined value, that is, when a large amount of power can be secured in the distributed power supply system, the switch control unit can supply power to the power supply target device.

[0028] Yet another characteristic configuration of the distributed power supply system according to the present invention is that the distributed power supply has a solar cell device, The power supply execution conditions include, as a requirement to be satisfied, that the generated power of the solar cell device is equal to or greater than a predetermined power.

[0029] According to the above characteristic configuration, in a distributed power supply system provided with a solar cell device as a distributed power supply, when the generated power of the solar cell device is equal to or greater than a predetermined power, that is, when a large amount of power can be secured in the distributed power supply system, the switch control unit can supply power to the power supply target device.

Brief Description of the Drawings

[0030]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

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Figure 8

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Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0031] <First Embodiment> Hereinafter, with reference to the drawings, a power supply relay device 20A(20) according to the first embodiment of the present invention and a distributed power supply system in which the same is provided will be described. FIGS. 1 and 2 are diagrams showing the configuration of a distributed power supply system in which the power supply relay device 20A according to the first embodiment is provided. FIG. 1 is a diagram showing the state during the interconnection operation of the distributed power supply system to the power grid 1. FIG. 2 is a diagram showing the state during the independent operation of the distributed power supply system. In FIGS. 1 and 2, the parts where power is being supplied are drawn with thick lines.

[0032] As shown in FIGS. 1 and 2, the distributed power system includes a power supply relay device 20A, a solar cell device 16 and a charge / discharge device 17 as distributed power sources, a power conditioner 10, and a power line 2.

[0033] The power line 2 to which the power load device 3 is connected is connected to a switchboard 4. The switchboard 4 is connected to the power grid 1 and the power conditioner 10. And the power load device 3 can receive power supply from at least one of the power grid 1 and the power conditioner 10.

[0034] The solar cell device 16 and the charge / discharge device 17 as distributed power sources and the power output terminal 22 of the power supply relay device 20A are connected to the power conditioner 10. Specifically, the power conditioner 10 includes a DC / DC conversion unit 13 to which the solar cell device 16 is connected, a DC / DC conversion unit 14 to which the charge / discharge device 17 is connected, and a DC / DC conversion unit 15 connected to the power output terminal 22 of the power supply relay device 20A. In addition, the power conditioner 10 includes an inverter 12 connected to each of the DC / DC conversion units 13, 14, 15 to convert the DC power into AC power, and a switch 11 connected to the AC side of the inverter 12. The switch 11 has a contact point a connected to the AC side of the inverter 12, a contact point b connected to the tie line 8, and a contact point c connected to the stand-alone line 9.

[0035] The tie line 8 is a line that is electrically connected to the power grid 1 when the power supply from the power grid 1 is being carried out normally. The stand-alone line 9 is a line that is electrically disconnected from the power grid 1 when the power supply from the power grid 1 is not being carried out normally and can receive power supply from other power sources.

[0036] The switch 11 switches between a state where the contact point a and the contact point b are connected, that is, a state where the power conditioner 10 is connected to the tie line 8, and a state where the contact point a and the contact point c are connected, that is, a state where the power conditioner 10 is connected to the self - contained line 9. Although detailed explanations are omitted, when the power supply from the power system 1 is being carried out normally, the switch 11 switches to the tie state where the contact point a and the contact point b are connected as shown in FIG. 1, and when the power supply from the power system 1 is not being carried out normally, it switches to the self - contained state where the contact point a and the contact point c are connected as shown in FIG. 2.

[0037] The switchboard 4 has a breaker 5, a breaker 6, and a switch 7. The switch 7 has a contact point a connected to the power line 2, a contact point b connected to the power system 1 side, and a contact point c connected to the self - contained line 9. And the switch 7 switches between a state where the contact point a and the contact point b are connected, that is, a state where the power line 2 is connected to the power system 1 side, and a state where the contact point a and the contact point c are connected, that is, a state where the power line 2 is connected to the self - contained line 9. Although detailed explanations are omitted, when the power supply from the power system 1 is being carried out normally, the switch 7 switches to the tie state where the contact point a and the contact point b are connected as shown in FIG. 1, and when the power supply from the power system 1 is not being carried out normally, it switches to the self - contained state where the contact point a and the contact point c are connected as shown in FIG. 2. Thus, the power line 2 can receive power supply from at least one of the power system 1 and the power conditioner 10 when the power supply from the power system 1 is being carried out normally, and can receive power supply from the power conditioner 10 when the power supply from the power system 1 is not being carried out normally.

[0038] The solar cell device 16 is a device that receives sunlight and generates electricity. The charge / discharge device 17 is a device that can discharge the electric power stored in a power storage unit (not shown) and charge the power storage unit with electric power. The power conditioner 10 controls operations such as receiving the electric power generated by the solar cell device 16, charging and discharging the electric power by the charge / discharge device 17, and outputting the electric power to the connection line 8 or the self - supporting line 9. In addition, the power conditioner 10 controls the operation of receiving electric power from the power supply relay device 20A.

[0039] The power supply relay device 20A includes a power input terminal 21 to which power is input, a power output terminal 22 that outputs power, a power conversion circuit 23 that is connected between the power input terminal 21 and the power output terminal 22 and performs a power conversion process of converting the power input to the power input terminal 21 into a predetermined power and then outputting it to the power output terminal 22, a detection terminal 24 connected to an external power detection part 19, and a circuit control part 25 that controls the operation of the power conversion circuit 23 based on the input power to the detection terminal 24. The power detection part 19 is provided on the connection line 8, and the power detection part 19 and the detection terminal 24 are connected by a connection detection line 18. The power conversion circuit 23 is controlled in operation by the circuit control part 25, and converts the AC power supplied from the power input terminal 21 into a predetermined DC power and outputs it to the power output terminal 22.

[0040] In addition, the power supply relay device 20A includes a power supply part 26 connected to the power input terminal 21, and operates using the power supplied through this power supply part 26, that is, the power input to the power input terminal 21. Therefore, when no power is input to the power input terminal 21, the circuit control part 25 of the power supply relay device 20A does not operate, and thus the power conversion process in the power conversion circuit 23 is not performed either.

[0041] To the terminal 40 connected to the power input terminal 21, various types of power supply devices 41 can be attached and removed. For example, the power supply device 41 can be an electric vehicle equipped with a power storage device, a fuel cell vehicle equipped with a fuel cell, etc. Additionally, the power supply device 41 can also be a vehicle equipped with an electrical outlet capable of outputting AC power, a portable power generation device, a portable power storage device, etc. In this embodiment, the case where the power supply device 41 outputs AC power is exemplified. And when the terminal 40 connected to the power input terminal 21 is connected to the power supply device 41, the power input from the power supply device 41 to the power input terminal 21 is supplied to the circuit control unit 25 via the power supply unit 26 and then supplied to the power conversion circuit 23. For example, a form can be considered where a user attaches an electrical plug as the terminal 40 to the AC 100V electrical outlet mounted on a vehicle as the power supply device 41, and the power supplied from the vehicle is provided to the distributed power system via the power supply relay device 20A.

[0042] Figure 3 is a flowchart for explaining the operation performed by the circuit control unit 25 in the power supply relay device 20A of the first embodiment. The circuit control unit 25 repeatedly executes this flowchart when receiving power supply via the power supply unit 26. That is, this flowchart is executed when the power supply device 41 is connected to the power input terminal 21. On the contrary, when the power supply device 41 is not connected to the power input terminal 21, the circuit control unit 25 cannot receive power supply and thus is not operating.

[0043] In Project #10, the circuit control unit 25 determines whether a predetermined processing execution condition including at least a condition regarding whether power is being supplied to the power detection part 19 is satisfied. In the case of this embodiment, the processing execution condition includes, as a condition to be satisfied, that power is not being supplied to the power detection part 19. That is, when power is not being supplied to the power detection part 19, the circuit control unit 25 determines that the processing execution condition is satisfied. Then, when the processing execution condition is satisfied, that is, when power is not being supplied to the power detection part 19, the circuit control unit 25 proceeds to Project #11, and when power is being supplied to the power detection part 19, the circuit control unit 25 proceeds to Project #12.

[0044] In Project #11, the circuit control unit 25 executes the power conversion process in the power conversion circuit 23. That is, when power is not being normally supplied to the power detection part 19 and there is an input voltage at the power input terminal 21, the circuit control unit 25 performs the power conversion process in the power conversion circuit 23.

[0045] Also, in Project #12, the circuit control unit 25 does not execute the power conversion process in the power conversion circuit 23. That is, even if there is an input voltage at the power input terminal 21, when power is being normally supplied to the power detection part 19, the circuit control unit 25 does not perform the power conversion process in the power conversion circuit 23.

[0046] As described above, in this embodiment, when the power supply to the power detection part 19 is being performed normally, the circuit control part 25 does not perform the power conversion process in the power conversion circuit 23, and when the power supply to the power detection part 19 is not being performed normally and there is an input voltage at the power input terminal 21, the circuit control part 25 is configured to perform the power conversion process in the power conversion circuit 23. In this embodiment, the power detection part 19 is provided on the tie line 8. That is, the power detection part 19 is a part where power is supplied when the power supply from the power system 1 is being performed normally, and power is not supplied when the power supply from the power system 1 is not being performed normally. Therefore, as shown in FIG. 1, when power is being supplied to the tie line 8, the circuit control part 25 determines that the power supply to the power detection part 19 is being performed normally, and as shown in FIG. 2, when power is not being supplied to the tie line 8, the circuit control part 25 determines that the power supply to the power detection part 19 is not being performed normally.

[0047] In the case of the connection state shown in FIG. 1, if the solar power generation device 16 is generating power, the generated power is supplied to at least one of the charge / discharge device 17 and the tie line 8 via the power conditioner 10. Also, there may be a case where the power supplied from the charge / discharge device 17 is supplied to the tie line 8 via the power conditioner 10. In this case, even if the circuit control part 25 assumes that the power supply device 41 has received the power via the power supply part 26 by being connected to the power input terminal 21, the circuit control part 25 does not perform the power conversion process in the power conversion circuit 23. That is, the power supply relay device 20A does not supply power to the power conditioner 10.

[0048] In the self - standing state shown in Fig. 2, if the solar cell device 16 is generating power, the generated power is supplied to at least one of the charge - discharge device 17 and the self - standing line 9 via the power conditioner 10. Also, in some cases, the power supplied from the charge - discharge device 17 is supplied to the self - standing line 9 via the power conditioner 10. Further, in some cases, the power supplied from the power supply device 41 is supplied to at least one of the self - standing line 9 and the charge - discharge device 17 via the power conditioner 10. In this case, when the power supply device 41 is connected to the power input terminal 21 and the circuit control unit 25 receives the power via the power supply unit 26, the power conversion circuit 23 performs power conversion processing. That is, power is supplied from the power supply relay device 20A to the power conditioner 10.

[0049] As described above, when a power supply device 41 having a power supply function is connected to the power input terminal 21, the power supply relay device 20A can convert the power input to the power input terminal 21 into a predetermined power by the power conversion circuit 23 and then supply it to the power output terminal 22. At this time, even if a power supply device 41 having a power supply function is connected to the power input terminal 21, the circuit control unit 25 does not perform the power conversion processing in the power conversion circuit 23 when the processing execution condition is not satisfied, and performs the power conversion processing in the power conversion circuit 23 when the processing execution condition is satisfied. That is, only when a power supply device 41 having a power supply function is connected to the power input terminal 21 and power supply is required from the power supply device 41 having a power supply function, the power input to the power input terminal 21 can be converted into a predetermined power by the power conversion circuit 23 and then supplied to the power output terminal 22.

[0050] <Second Embodiment> The power supply relay device 20B(20) and the distributed power system of the second embodiment are different from the above - described embodiment in that they include a power generation input terminal 27 to which a power generation device is connected. The power supply relay device 20B and the distributed power system of the second embodiment will be described below, and the description of the same configuration as the above - described embodiment will be omitted.

[0051] FIG. 4 and FIG. 5 are diagrams showing the configuration of a distributed power system in which the power supply relay device 20B of the second embodiment is provided. FIG. 4 is a diagram showing the state during the interconnection operation to the power system 1 of the distributed power system. FIG. 5 is a diagram showing the state during the independent operation of the distributed power system. In FIGS. 4 and 5, portions where power is being supplied are drawn with thick lines.

[0052] The power conditioner 10 includes a DC / DC conversion unit 14 to which the charge / discharge device 17 is connected, and a DC / DC conversion unit 15 connected to the power output terminal 22 of the power supply relay device 20B. In addition, the power conditioner 10 includes an inverter 12 connected to each of the DC / DC conversion units 14, 15 to convert the DC power into AC power, and a switch 11 connected to the AC side of the inverter 12.

[0053] The power supply relay device 20B includes a power generation input terminal 27 to which the solar cell device 16 as a power generation device is connected, and a switching unit 28 that connects the power output terminal 22 to the power generation input terminal 27 and does not connect the power output terminal 22 to the power conversion circuit 23 when power supply to the power detection part 19 is being performed normally, and connects the power output terminal 22 to the power conversion circuit 23 when power supply to the power detection part 19 is not being performed normally.

[0054] The switching unit 28 included in the power supply relay device 20B has a switch 28a and a coil 28b. The coil 28b of the switching unit 28 is electrically connected to an interconnection detection line 18 connected to the power detection part 19. In the switching unit 28, the contact a of the switch 28a is connected to the power output terminal 22, the contact c of the switch 28a is connected to the power generation input terminal 27, and the contact b of the switch 28a is connected to the power conversion circuit 23. The power output terminal 22 is connected to the power conditioner 10, and the power generation input terminal 27 is connected to the solar cell device 16.

[0055] During the interconnection operation shown in FIG. 4, the coil 28b of the switching unit 28 is energized by the power supplied from the interconnection line 8. As a result, the contact a and the contact c of the switch 28a of the switching unit 28 are connected. Then, the photovoltaic device 16 is connected to the DC / DC conversion unit 15 of the power conditioner 10 via the power generation input terminal 27, the contact c of the switch 28a, the contact a, and the power output terminal 22.

[0056] During the independent operation shown in FIG. 5, since no power is supplied from the interconnection line 8, the coil 28b of the switching unit 28 is not energized. As a result, the contact a and the contact b of the switch 28a of the switching unit 28 are connected. Then, the power conversion circuit 23 is connected to the DC / DC conversion unit 15 of the power conditioner 10 via the contact b of the switch 28a, the contact a, and the power output terminal 22.

[0057] In this way, when the power supply to the power detection part 19 is being normally performed, the switching unit 28 connects the power output terminal 22 to the power generation input terminal 27 and does not connect the power output terminal 22 to the power conversion circuit 23. When the power supply to the power detection part 19 is not being normally performed, the switching unit 28 connects the power output terminal 22 to the power conversion circuit 23.

[0058] <Third Embodiment> The power supply relay device 20C(20) and the distributed power system of the third embodiment differ from the above-described embodiments in the method of receiving power supply. The power supply relay device 20C and the distributed power system of the third embodiment will be described below. The description of the same configuration as that of the above-described embodiments will be omitted.

[0059] FIGS. 6 to 8 are diagrams showing the configuration of a distributed power system in which the power supply relay device 20C of the third embodiment is provided. FIG. 6 is a diagram showing a state in which the power supply device 41 is not connected to the power input terminal 21 during the interconnection operation of the distributed power system to the power grid 1. FIG. 7 is a diagram showing a state in which the power supply device 41 is not connected to the power input terminal 21 during the stand-alone operation of the distributed power system. FIG. 8 is a diagram showing a state in which the power supply device 41 is connected to the power input terminal 21 during the stand-alone operation of the distributed power system. In FIGS. 6 to 8, the portions where power is being supplied are drawn with thick lines.

[0060] The power supply relay device 20C includes a power generation input terminal 27 to which a power generation device is connected, and a switching unit 30 that connects the power output terminal 22 to the power generation input terminal 27 and does not connect the power output terminal 22 to the power conversion circuit 23 when the power supply to the power detection part 19 is being performed normally, and connects the power output terminal 22 to the power conversion circuit 23 when the power supply to the power detection part 19 is not being performed normally.

[0061] The switching unit 30 included in the power supply relay device 20C is configured using two magnetic contactors 30a and 30b. The circuit control unit 25 switches the conduction state and the non-conduction state of the magnetic contactors 30a and 30b. When the magnetic contactor 30a is in the conduction state, the power conversion circuit 23 is connected to the power output terminal 22, and when the magnetic contactor 30a is in the non-conduction state, the power conversion circuit 23 is not connected to the power output terminal 22. When the magnetic contactor 30b is in the conduction state, the solar cell device 16 is connected to the power output terminal 22, and when the magnetic contactor 30b is in the non-conduction state, the solar cell device 16 is not connected to the power output terminal 22.

[0062] The power supply unit 26 can receive power supply from the power switchover unit 29. The power switchover unit 29 has a switch 29a and a coil 29b. The coil 29b of the power switchover unit 29 is connected to the power input terminal 21. The contact point a of the switch 29a is connected to the power supply unit 26, the contact point c of the switch 29a is connected to the power input terminal 21, the contact point b of the switch 29a is connected to the self - supporting terminal 36 provided in the power supply relay device 20C, and the self - supporting terminal 36 is connected to the self - supporting line 9 via the connection line 35. As shown in FIGS. 6 and 7, when the power supply device 41 is not connected to the power input terminal 21, the coil 29b is not energized, so the contact point a and the contact point b of the switch 29a are connected. On the contrary, as shown in FIG. 8, when the power supply device 41 is connected to the power input terminal 21, the coil 29b is energized, so the contact point a and the contact point c of the switch 29a are connected.

[0063] In the case of the linked operation shown in FIG. 6, the power supply device 41 is not connected to the power input terminal 21, and the self - supporting line 9 is not energized. Since power is not supplied to the power supply unit 26, the power supply relay device 20C cannot operate. In this case, both the magnetic contactors 30a and 30b are in the non - conductive state.

[0064] In the case of the self - supporting operation shown in FIG. 7, the power supply device 41 is not connected to the power input terminal 21, but the self - supporting line 9 is energized. Since power is supplied to the power supply unit 26 from the self - supporting line 9 via the connection line 35, the self - supporting terminal 36, and the power switchover unit 29, the power supply relay device 20C can operate. In this case, the circuit control unit 25 switches the magnetic contactor 30a to the non - conductive state and switches the magnetic contactor 30b to the conductive state. As a result, the power supplied from the solar cell device 16 is supplied to the power conditioner 10.

[0065] In the case of autonomous operation shown in FIG. 8, the power supply device 41 is connected to the power input terminal 21, and the autonomous line 9 is energized. Then, power is supplied from the power input terminal 21 to the power supply unit 26, and the power supply relay device 20C can operate. In addition, there is also an input voltage on the input side (AC side) of the power conversion circuit 23. In this case, the circuit control unit 25 switches the magnetic contactor 30a to the conductive state and switches the magnetic contactor 30b to the non-conductive state. As a result, the power supplied from the power supply device 41 is supplied to the power conditioner 10.

[0066] FIG. 9 is a flowchart for explaining the operation performed by the circuit control unit 25 in the power supply relay device 20C according to the third embodiment. The circuit control unit 25 repeatedly executes this flowchart when receiving power supply via the power supply unit 26. Note that, as shown in FIG. 6, when the circuit control unit 25 is not receiving power supply, this flowchart is not executed because the circuit control unit 25 cannot operate.

[0067] In the case of this embodiment, the power supply unit 26 can receive power supply from the power supply device 41 connected to the power input terminal 21 or the autonomous line 9 via the power switch unit 29. Therefore, even when the circuit control unit 25 is receiving power supply, there may be a case where the power supply device 41 is not connected to the power input terminal 21. Therefore, in step #20, the circuit control unit 25 determines whether there is an input voltage at the power input terminal 21. For example, when there is an input voltage on the input side (i.e., the AC side) of the power conversion circuit 23, the circuit control unit 25 determines that there is an input voltage at the power input terminal 21 and proceeds to step #21, and when there is no input voltage on the input side (i.e., the AC side) of the power conversion circuit 23, the circuit control unit 25 determines that there is no input voltage at the power input terminal 21 and proceeds to step #23.

[0068] In Step #21, the circuit control unit 25 determines whether a predetermined process execution condition including at least a condition regarding whether power is being supplied to the power detection part 19 is satisfied. In the case of the present embodiment, the process execution condition includes, as a condition to be satisfied, that power is not being supplied to the power detection part 19. That is, when power is not being supplied to the power detection part 19, the circuit control unit 25 determines that the process execution condition is satisfied. Then, when the process execution condition is satisfied, that is, when power is not being supplied to the power detection part 19, the circuit control unit 25 proceeds to Step #22, and when power is being supplied to the power detection part 19, the circuit control unit 25 proceeds to Step #23.

[0069] In Step #22, the circuit control unit 25 uses the switching unit 30 to connect the power conversion circuit 23 to the power output terminal 22 and not connect the power generation input terminal 27 to the power output terminal 22. In addition, the circuit control unit 25 executes power conversion processing in the power conversion circuit 23. That is, when power is not being supplied normally to the power detection part 19 (i.e., when the answer in Step #21 is "Yes") and there is an input voltage at the power input terminal 21 (i.e., when the answer in Step #20 is "Yes"), the circuit control unit 25 performs power conversion processing in the power conversion circuit 23. This state corresponds to the state shown in FIG. 8.

[0070] Also, in Step #23, the circuit control unit 25 uses the switching unit 30 to not connect the power conversion circuit 23 to the power output terminal 22 and connect the power generation input terminal 27 to the power output terminal 22. In addition, the circuit control unit 25 does not execute power conversion processing in the power conversion circuit 23. That is, when power is being supplied normally to the power detection part 19 (i.e., when the answer in Step #21 is "No"), or when there is no input voltage at the power input terminal 21 (i.e., when the answer in Step #20 is "No"), the circuit control unit 25 does not perform power conversion processing in the power conversion circuit 23.

[0071] <Fourth Embodiment> The power supply relay device 20D (20) and the distributed power system according to the fourth embodiment are different from the above-described embodiments in that they have a power supply function for a power supply target device. The power supply relay device 20D and the distributed power system according to the fourth embodiment will be described below, but descriptions of the same configurations as those in the above-described embodiments will be omitted.

[0072] FIG. 10 is a diagram showing the configuration of a distributed power system in which the power supply relay device 20D according to the fourth embodiment is provided. As shown in the figure, the power supply relay device 20D includes a power supply changeover switch 31 and a switch control unit 32.

[0073] The power supply changeover switch 31 switches between a power supply state in which the power supplied from the power line 2 via the power receiving line 37 connected to the power line 2 is supplied to the power supply terminal 38 attachable to the power supply target device, and a non-power supply state in which the power is not supplied to the power supply terminal 38. In the example shown in FIG. 10, the contact a of the power supply changeover switch 31 is connected to the power receiving end 34 provided in the power supply relay device 20D. The power receiving end 34 is connected to the power line 2 between the switchboard 4 and the power load device 3 via the power receiving line 37. In the present embodiment, power is supplied to the power line 2 in both the case of interconnection operation and the case of independent operation. Therefore, power is also supplied to the power supply changeover switch 31 in both the case of interconnection operation and the case of independent operation. The contact b of the power supply changeover switch 31 is connected to the power supply end 33 provided in the power supply relay device 20D. The power supply end 33 is connected to the power supply terminal 38, and a power supply device 41 as a power supply target device can be connected to the power supply terminal 38. The power supply device 41 as a power supply target device is, for example, an electric vehicle including a power storage device, a portable power storage device, or the like. When the contact a and the contact b of the power supply changeover switch 31 are connected, the above-described power supply state is established, and when the contact a and the contact b of the power supply changeover switch 31 are not connected, the above-described non-power supply state is established. For example, a form in which a user attaches the power supply terminal 38 to a power supply port mounted on a vehicle as the power supply device (power supply target device) 41, and the power supplied from the power line 2 is provided to the vehicle via the power supply changeover switch 31 of the power supply relay device 20D can be considered.

[0074] When a predetermined power supply execution condition is satisfied, the switch control unit 32 switches the power supply switching switch 31 to the power supply state, and when the power supply execution condition is not satisfied, the switch control unit 32 switches the power supply switching switch 31 to the non-power supply state. Power is supplied to the switch control unit 32 from the power line 2. The content of the power supply execution condition can be set as appropriate.

[0075] Specifically, the power supply execution condition may include, as a requirement to be satisfied, that the current time is within a predetermined power supply execution time zone in which power supply to the power supply terminal 38 is permitted. For example, the power supply execution time zone is from 7:00 to 17:00. If it is within this time zone, since power generation is performed by the solar power generation device 16, it is expected that even if power is supplied to the power supply device 41, the received power from the power grid 1 will not become excessive.

[0076] Alternatively, the power supply execution condition may include, as a requirement to be satisfied, that no power supply is being performed to the power detection part 19. In the present embodiment, information that can determine whether power is being supplied to the detection terminal 24, that is, whether power is being supplied to the power detection part 19, is transmitted to the switch control unit 32. As a result, the switch control unit 32 can determine whether the power supply from the power grid 1 is being performed normally. In the case shown in FIG. 10, since the power supply from the power grid 1 is not being performed normally, the switch control unit 32 determines that the power supply execution condition is satisfied.

[0077] <Fifth Embodiment> The content of the power supply execution condition described above can be changed as appropriate. The power supply relay device 20D and the distributed power system of the fifth embodiment will be described below, but the description of the same configuration as the above embodiment will be omitted.

[0078] FIG. 11 is a diagram showing the configuration of a distributed power system in which the power supply relay device 20D of the fifth embodiment is provided. As shown in the figure, the information communication device 42 can collect information from the solar cell device 16 and the charge / discharge device 17 and transmit the information to the power supply relay device 20D. The information communication device 42 is a device that controls the operation of controlled devices (i.e., the power supply relay device 20D, the solar cell device 16, the charge / discharge device 17, etc.), such as a HEMS (Home Energy Management System). It can perform information communication via a communication line with the controlled devices, receive information from each device, and transmit information to each device. In the case of this embodiment, the information communication device 42 collects information about the remaining charge of the charge / discharge device 17 as a distributed power source and information about the generated power of the solar cell device 16 as a distributed power source, and transmits the information to the power supply relay device 20D.

[0079] And the above-described power supply execution conditions include, as requirements to be satisfied, that the remaining charge of the charge / discharge device 17 is equal to or greater than a predetermined value. That is, when the remaining charge of the charge / discharge device 17 transmitted is equal to or greater than the predetermined value (i.e., when the power supply execution conditions are satisfied), the switch control unit 32 switches the power supply changeover switch 31 to the power supply state to enable power supply to the power supply device 41, and when the remaining charge of the charge / discharge device 17 is less than the predetermined value (i.e., when the power supply execution conditions are not satisfied), the switch control unit 32 switches the power supply changeover switch 31 to the non-power supply state to prohibit power supply to the power supply device 41.

[0080] Further, the power supply execution conditions may include, as requirements to be satisfied, that the generated power of the solar cell device 16 is equal to or greater than a predetermined power. That is, when the generated power of the solar cell device 16 transmitted is equal to or greater than the predetermined power (i.e., when the power supply execution conditions are satisfied), the switch control unit 32 switches the power supply changeover switch 31 to the power supply state to enable power supply to the power supply device 41, and when the generated power of the solar cell device 16 is less than the predetermined power (i.e., when the power supply execution conditions are not satisfied), the switch control unit 32 switches the power supply changeover switch 31 to the non-power supply state to prohibit power supply to the power supply device 41.

[0081] <Alternative Embodiment> <1> In the above embodiment, specific examples of the power supply relay device 20 and the distributed power system of the present invention have been described, but the configuration can be changed as appropriate. For example, the number of solar cell devices 16 etc. connected to the power conditioner 10 is not limited to the above-described example and can be changed as appropriate. Although the solar cell device 16 and the charge / discharge device 17 have been exemplified as the distributed power sources, other power sources may be used.

[0082] Also, the power supply relay device 20 may be provided with a switch for switching between the conductive state and the non-conductive state between the power input terminal 21 and the power conversion circuit 23. Then, when the above processing execution condition is not satisfied, the power conversion process in the power conversion circuit 23 is not performed by switching the switch to the non-conductive state, and when the above processing execution condition is satisfied and there is an input voltage at the power input terminal 21, the power conversion process in the power conversion circuit 23 may be performed by switching the switch to the conductive state.

[0083] <2> In the above embodiment, the content of the processing execution condition can be changed as appropriate. Taking a specific example, in addition to the fact that no power supply is being performed at the power detection part 19, the processing execution condition may include that the current time is within a predetermined processing execution time zone in which power conversion processing is permitted. For example, if a storage part (not shown) of the power supply relay device 20D stores the processing execution time zones in which power conversion processing is permitted, such as from time 19:00 to time 24:00 and from time 0:00 to time 5:00, the power conversion process in the power conversion circuit 23 is not performed outside that time zone.

[0084] <3> In the above embodiment, a plurality of power detection parts 19, 43 may be provided. FIG. 12 is a diagram showing the configuration of a distributed power system in which a power supply relay device 20E (20) according to another embodiment is provided. As shown in the figure, the power detection part includes a first detection part 19 that supplies power when the power supply from the power grid 1 is normal and does not supply power when the power supply from the power grid 1 is not normal, and a second detection part 43 that does not supply power when the power supply from the power grid 1 is normal and can be supplied with power from another power source when the power supply from the power grid 1 is not normal. The first detection part 19 as the power detection part is provided on the tie line 8, and the first detection part 19 and the detection end (first detection end) 24 are connected by a tie detection line 18. The second detection part 43 as the power detection part is provided on the self - supporting line 9, and the second detection part 43 and the detection end (second detection end) 44 are connected by a self - supporting detection line 39.

[0085] And the processing execution condition includes, as a condition to be satisfied, a transition from a state where the power conversion process in the power conversion circuit 23 is not performed and power is supplied to at least one of the first detection part 19 and the second detection part 43, to a state where the power conversion process in the power conversion circuit 23 is not performed and power is not supplied to both the first detection part 19 and the second detection part 43.

[0086] For example, when the circuit control unit 25 determines that the processing execution condition is satisfied when the power supply from the power conditioner 10 to the self - supporting line 9 is interrupted because the charge - discharge device 17 cannot discharge and the solar cell device 16 cannot generate power during self - operation. And in such a case, power is supplied from the power supply device 41 to the power conditioner 10 via the power supply relay device 20E, and the power is supplied to the power load device 3. When the circuit control unit 25 determines that the processing execution condition is satisfied and starts the power supply from the power supply device 41 to the power conditioner 10, it may perform control to continue the power supply for a certain period of time.

[0087] <4> In the above-described embodiment, several examples of processing execution conditions were illustrated. However, these conditions may be used alone, or these conditions may be used in combination.

[0088] <5> In the above-described embodiment, several examples of power supply execution conditions were illustrated. However, these conditions may be used alone, or these conditions may be used in combination.

[0089] <6> Note that the configurations disclosed in the above-described embodiment (including other embodiments, the same applies hereinafter) can be applied in combination with the configurations disclosed in other embodiments as long as no contradiction occurs. Also, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these, and can be appropriately modified within the scope not departing from the object of the present invention.

Industrial Applicability

[0090] The present invention can be used for a power supply relay device and a distributed power source system that can effectively utilize a device having a power supply function.

Explanation of Signs

[0091] 1 Power grid 16 Photovoltaic device 17 Charge and discharge device 18 Connection detection line 19 Power detection part (first detection part) 20 Power supply relay device 21 Power input terminal 22 Power output terminal 23 Power conversion circuit 24 Detection terminal (first detection terminal) 25 Circuit control unit 26 Power supply unit 27 Power generation input terminal 28 Switching part 30 Switching part 31 Power supply switching switch 32 Switch control unit 38 Power supply terminal 40 Terminals 41 Power supply device (device to be powered) 43 Electric power detection part (second detection part) 44 Detection terminal (second detection terminal)

Claims

1. a power input terminal to which power is input; a power output terminal that outputs power; a power conversion circuit connected between the power input terminal and the power output terminal, which performs a power conversion process of converting the power input to the power input terminal into a predetermined power and then outputting it to the power output terminal; a detection terminal connected to an external power detection part; a circuit control unit that controls the operation of the power conversion circuit based on the input power to the detection terminal, and the power detection part has a first detection part that supplies power when the power supply from the power grid is normal and does not supply power when the power supply from the power grid is not normal, and a second detection part that does not supply power when the power supply from the power grid is normal and can supply power from another power source when the power supply from the power grid is not normal; the circuit control unit, as a condition to be satisfied, does not perform the power conversion process in the power conversion circuit when a predetermined process execution condition including a transition from a state where the power conversion process in the power conversion circuit is not performed and power is supplied to at least one of the first detection part and the second detection part to a state where the power conversion process in the power conversion circuit is not performed and power is not supplied to both the first detection part and the second detection part is not satisfied, and is configured to perform the power conversion process in the power conversion circuit when the process execution condition is satisfied and there is an input voltage at the power input terminal. A power supply relay device.

2. The power supply relay device according to claim 1, wherein the process execution condition includes, as a condition to be satisfied, that the current time is within a predetermined process execution time zone in which it is allowed to perform the power conversion process.

3. a power generation input terminal to which a power generation device is connected; a switching unit that connects the power output terminal to the power generation input terminal and does not connect the power output terminal to the power conversion circuit when the power supply to the power detection part is normal, and connects the power output terminal to the power conversion circuit when the power supply to the power detection part is not normal. The power supply relay device according to claim 1 or 2.

4. A power supply relay device according to any one of claims 1 to 3; a distributed power source; a power conditioner to which the power output terminals of the distributed power source and the power supply relay device are connected, A distributed power system comprising a power line that can receive power supply from at least one of the power system and the power conditioner when the power supply from the power system is being carried out normally, and can receive power supply from the power conditioner when the power supply from the power system is not being carried out normally.

5. The distributed power system according to claim 4, wherein the power supply relay device includes a power supply switching switch that switches between a power supply state in which power supplied from the power line through a power receiving line connected to the power line is supplied to a power supply terminal attachable to a power supply target device, and a non-power supply state in which the power is not supplied to the power supply terminal, and a switch control unit that switches the power supply switching switch to the power supply state when a predetermined power supply execution condition is satisfied, and switches the power supply switching switch to the non-power supply state when the power supply execution condition is not satisfied.

6. The distributed power system according to claim 5, wherein the power supply execution condition includes, as a requirement to be satisfied, that the current time is within a predetermined power supply execution time zone in which power supply to the power supply terminal is permitted.

7. The power detection part is a part where power supply is carried out when the power supply from the power system is being carried out normally, and power supply is not carried out when the power supply from the power system is not being carried out normally. The distributed power system according to claim 5 or 6, wherein the power supply execution condition includes, as a requirement to be satisfied, that no power supply is carried out to the power detection part.

8. The distributed power source has a charge and discharge device. The distributed power system according to any one of claims 5 to 7, wherein the power supply execution condition includes, as a requirement to be satisfied, that the remaining charge amount of the charge and discharge device is equal to or more than a predetermined value.

9. The distributed power source has a solar cell device. The distributed power system according to any one of claims 5 to 8, wherein the power supply execution condition includes, as a requirement to be satisfied, that the generated power of the solar cell device is equal to or more than a predetermined power.

Images