JP2000253585A - Distributed power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distributed power supply system, wherein a plurality of distributed power supply units can be operated in parallel without troublesome setting. SOLUTION: A distributed power supply system comprises distributed power supply units 7, which allow network separation between direct-current power supplies 8 and a commercial power supply 1 and a display 15, capable of indicating the condition of operation of the distributed power supply units 7. The display 15 is provided with a plurality of terminals 15f, to which the distributed power supply units 7 are connectable, a transmission and reception circuit 15a, which transmits confirmation signals to the connection terminals 15f and receives reply signals corresponding to the confirmation signals from the distributed power supply units 7, and an operation control circuit 15b which determines the condition of connection for the distributed power supply units 7, from the presence or absence of a reply signal received by the transmitting and receiving circuit 15a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply using a DC power supply such as a solar cell, which is electrically connected to a commercial power supply.
The present invention relates to a distributed power supply system that performs a system interconnection operation so as to supply power to a common load.

[0002]

2. Description of the Related Art FIG. 3 is a schematic configuration diagram of a conventional distributed power supply (solar power generation apparatus) using a solar cell as a DC power supply. In FIG. 3, 1 is a power system of a commercial power supply,
A main power source 2 of the power plant, a power plant 3 that steps down the power from the power plant 2 and distributes the power, a circuit breaker 5 provided on the distribution line 4,
A pole transformer 6 for reducing the supplied electric power and supplying it to each home. Reference numeral 8 denotes a solar cell installed in each home. The distributed power source 7 includes a grid-connected power converter 10 that converts a DC voltage output from the solar cell 8 into an AC voltage. Reference numeral 12 denotes a system interconnection protection circuit, which is a disconnection switch 11 when the state of the commercial power supply 1 is normal.
To link the distributed power source 7 with the commercial power source 1. When an abnormality or power failure of the commercial power supply 1 is detected, the power converter 9 stops supplying power to the commercial power supply 1, disconnects the disconnecting switch 11 to separate the distributed power supply 7 from the system, When the power outage is no longer detected, the disconnecting switch 11 is operated to connect the distributed power source 7 and the commercial power source 1 to the system again.

When the system interconnection protection circuit 12 recognizes that the commercial power supply 1 is normal and performs system interconnection, power is supplied to the shared branch circuit 16 from the commercial power supply 1 and the interconnection protection circuit 12 When it is determined that 1 is abnormal / power failure, power is supplied from the power converter 9.

In the distributed power supply device having the above-described configuration,
When DC power is output from the solar cell 8, the power is converted into AC power of a predetermined frequency by the power converter 9 and the AC power is supplied to the load in the house, while the power that cannot be covered by the AC power from the distributed power source Is supplied from the commercial power supply 1.

In the basic configuration of the distributed power supply device shown in FIG. 3, reference numeral 8 denotes a solar cell, and reference numeral 10 denotes a grid-connected power converter. This grid-connected power converter 10 includes the above-described power converter 9, a parallel-off switch 11, and a grid-connected protection circuit 12. In addition, the grid-connected power converter 10 has a display 15 connected by a cable 14.

[0006] The display 15 displays the solar cells 8 of the distributed power source 7 so that the user can easily grasp the power generation state of the distributed power source.
, The power generation amount, the integrated power amount, the state of the commercial power supply 1, and the state of the grid-connected power converter 10.

[0007]

In the case of a distributed power supply system (see FIG. 4) in which a plurality of distributed power supply units having the above-described configuration are connected to the commercial power supply 1 in parallel and operated, a plurality of distributed power supply units are operated. The connected display 15 displays the operation status of each distributed power source 7, the state of the commercial power source 1, the integrated value of the generated power of each distributed power source, and notifies the distributed power source 7 of a control command such as operation / stop. It is supposed to. in this way,
In order to communicate with a plurality of distributed power supplies 7 using one display 15 and acquire various data, it is necessary to make the display 15 recognize the number of connected distributed power supplies 7.

However, in order for the display unit 15 to recognize the number of connected distributed power sources 7, a switch 15e is provided, and by operating the switch 15e, the connection terminal to which the distributed power source 7 is connected is set. Such a complicated work is required. Also,
If the switch 15e is set incorrectly, the display 15 and the distributed power source 7
There is a problem that the distributed power supply system may not operate normally because communication with the power supply is not performed.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a distributed power supply system capable of operating a plurality of distributed power supply apparatuses in parallel without performing complicated settings. To provide.

[0010]

According to the first aspect of the present invention,
A DC power supply, a power converter for converting DC output from the DC power supply to AC, and, when an abnormality / power failure of the commercial power supply is detected, stopping the power supply output from the power converter to the commercial power supply and performing system separation, When the abnormality of the commercial power supply / release of the power failure is detected, the distributed power supply having a grid connection protection device that performs grid connection and restarts the power supply from the power converter to the commercial power supply, and the power from the commercial power supply during grid connection. A distributed power supply device including a shared branch circuit to which power is supplied from the power converter at the time of power supply and system separation, a plurality of terminals to which each distributed power supply device can be connected, and a confirmation signal transmitted to each connection terminal, A transmission / reception circuit that receives a return signal from the distributed power supply device in response to the confirmation signal; and an operation control circuit that determines a connection state of the distributed power supply device based on the presence or absence of the return signal received by the transmission / reception circuit. And 示器 and is characterized in that it consists of.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A distributed power system according to one embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a schematic configuration diagram of a distributed power supply system. FIG. 2 is a flowchart showing the operation of the display unit of the distributed power supply system. Note that the same parts as those of the distributed power supply device and the distributed power supply system shown in the section of the related art are denoted by the same reference numerals, and detailed description thereof will be omitted.

The distributed power source 7 is constituted by a solar cell 8 corresponding to a DC power source and a system interconnection type power converter 10.
The distributed power supply system 18 includes a plurality of distributed power supplies 7 and the display 15. The grid-connected power converter 10 includes a power converter 9, a parallel-off switch 11, a grid-connected protection device 12, a transmission / reception circuit 19, and a sensor unit 17. The display 15 is provided with a transmitting / receiving circuit 15a
, Operation control circuit 15b, display unit 15c, operation unit 1
5d, and a connection terminal 15f for connecting a plurality of distributed power sources 7.

The power converter 9 converts DC power input from the solar cell 8 as a DC power supply into AC, and outputs AC power to the commercial power supply 1 when the power system is connected, and to the shared branch circuit 16 when the power system is separated. Things. The disconnection switch 11 is a switch for connecting and disconnecting the distributed power supply 7 and the commercial power supply 1, and is controlled by the system interconnection protection device 12.

The system interconnection protection device 12 outputs a control signal for controlling the power converter 9 when signals from the voltage sensor and the current sensor provided in the sensor unit 17 are input. Further, the system interconnection protection device 12 detects a frequency abnormality or a voltage abnormality in the system of the distributed power supply 7 or a power failure of the commercial power supply 1 based on a voltage signal or a current signal from the sensor unit 17, and disconnects based on the abnormality. By controlling the switch 11, the distributed power supply 7 is disconnected from the commercial power supply 1, the AC output to the commercial power supply 1 is stopped by the power converter 9, and when the system separation is confirmed, the shared branch circuit 16 is connected to the power converter 9. To restart output. When it is detected that the abnormality and the power failure of the commercial power supply 1 have been eliminated, the power converter 9 stops the output of the AC power to the shared branch circuit 16 and controls the parallel-off switch 11 to reconnect the distributed power supply 7 to the system. The power converter 9 restarts the AC current output to the commercial power supply 1 when the system interconnection is confirmed.

Further, the interconnection protection device 12 notifies the display 15 of the operation state of the distributed power source 7 such as the state of the solar cell voltage and the system voltage, the operation state of the power converter 9, and the presence or absence of an abnormality. As means for that purpose, the grid-connected power converter 10
Is a transmission / reception circuit 19, and the display 15 is a transmission / reception circuit 15a.
Is provided. The transmission and reception circuits 19 and 15a may be wired communication or wireless communication.

The display unit 15 performs an operation based on the transmission / reception circuit 15a and the notified operating state of each distributed power supply 7, determines a command for controlling the operation of the distributed power supply system 18, and displays the display unit 15c. An operation control circuit 15b for determining the content to be displayed on the display, a display unit 15c for displaying the display content determined by the operation control circuit 15b, and an operation device 15d for receiving a user's request such as start or stop of operation. , Connection terminals 15f1 to 15fn (n is the maximum number of connected distributed power sources 7).

Next, a method of recognizing the number of connected distributed power sources 7 connected to the display 15 in the distributed power system 18 according to the present embodiment will be described with reference to FIG. The operation control circuit 15b of the display 15 transmits a confirmation signal to the distributed power source 7 using the transmission / reception circuit 15a every time the power is turned on. The distributed power supply 7 that has been notified of the confirmation signal displays the
Is notified to the display using the transmission / reception circuit 19. The display 15 notified of the reply recognizes that the distributed power source 7 is connected to the connection terminal 15f.

The same process is performed on the remaining connection terminals 15f to determine whether or not the distributed power source 7 is connected. If there is no reply from the distributed power source 7, it is determined that the distributed power source 7 is not connected to the connection terminal 15f.

The connection terminal 15 of the display 15 has this processing.
By repeating f1 to 15fn the number of times (n times in the present embodiment), the display 15 can recognize the number of distributed power supplies 7 constituting the distributed power supply system 18 and the distributed power supply 7 is connected. It is possible to distinguish between the connection terminal 15f that is connected and the connection terminal 15f that is not connected. Further, even if the number of distributed power supplies 7 is changed after the distributed power supply system 18 is installed at the user's house, complicated processing using the conventional switch 15e is performed because the above-described processing is performed every time the power supply is started. No need. Further, in the distributed power supply system 18 of the present embodiment,
There is an effect that it is possible to prevent the system from malfunctioning due to erroneous setting of the switch 15e, which is conventionally required. In the present embodiment, the connection terminal 15f connected when the power is turned on is checked, but it goes without saying that the check is not limited to this.

[0020]

As described above, according to the first aspect of the present invention, a DC power supply, a power converter for converting a DC output from the DC power supply into an AC, and an abnormality / power failure of a commercial power supply are detected. Then, the power supply output from the power converter to the commercial power supply is stopped to separate the system, and when the abnormality of the commercial power supply / release of the power failure is detected, the system is connected to restart the power supply from the power converter to the commercial power supply. A distributed power supply including a distributed power supply having a grid connection protection device, a shared branch circuit that is supplied with power from a commercial power supply when the grid is connected, and is supplied with power from a power converter when the grid is separated, and each distributed power supply. A plurality of terminals that can be connected, a transmitting / receiving circuit that transmits a confirmation signal to each connection terminal, and receives a reply signal from the distributed power supply device in response to the confirmation signal, and the presence / absence of a reply signal received by the transmitting / receiving circuit And an operation control circuit for judging the connection state of the distributed power supply device. The connection terminals are automatically connected without setting the connection recognition switch, which was conventionally required. This makes it possible to provide a distributed power supply system capable of operating a plurality of distributed power supply devices in parallel without performing complicated settings.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a distributed power supply system.

FIG. 2 is a flowchart illustrating an operation of a display unit of the distributed power supply system.

FIG. 3 is a schematic configuration diagram of a conventional distributed power supply device.

FIG. 4 is a schematic configuration diagram of a conventional distributed power supply system.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Commercial power supply 7 Distributed power supply 8 Solar cell 9 Power converter 10 Grid-connected power converter 11 Off-line switch 12 System fan-shaped control circuit 13 House load 15 Display 15a Transmission / reception circuit 15b Operation control circuit 15c Display 15d Operation Unit 15e Distributed power connection recognition switch 15f Distributed power connection terminal 16 Shared branch circuit 17 Sensor unit 18 Distributed power system 19 Transmitter / receiver circuit 20 Outlet for shared branch circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hirotada Higashihama 1048 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Inventor Shinichiro Okamoto 1048, Kadoma, Kadoma, Osaka Prefecture, Matsushita Electric Works Co., Ltd. Tadayoshi 1048 Kadoma Kadoma, Kadoma-shi, Osaka Matsushita Electric Works F-term (reference) 5G066 HA06 HA13 HB03 HB05

Claims (1)

[Claims] A DC power supply; a power converter for converting DC output from the DC power supply to an AC; and a system for stopping power supply output from the power converter to the commercial power supply when an abnormality / power failure of the commercial power supply is detected. A distributed power supply equipped with a grid connection protection device that performs grid connection and resumes power supply from the power converter to the commercial power supply when power supply is disconnected from the power supply and power failure is detected. Check the distributed power supply unit that has a shared branch circuit that is supplied with power from the commercial power supply and is supplied with power from the power converter when the system is separated, multiple terminals to which each distributed power supply unit can be connected, and each connection terminal. A transmission / reception circuit that transmits a signal and receives a return signal from the distributed power supply in response to the confirmation signal, and an operation control that determines a connection state of the distributed power supply based on the presence or absence of the return signal received by the transmission / reception circuit. Distributed power system comprising a display and a road, in that it consists of.