JP2008172897A - Transfer stop system for distributed power supplies - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To disconnect distributed power supplies quickly and surely without using a communication line when a failure occurs in a power distribution system. <P>SOLUTION: A transfer stop system for distributed power supplies 1 is constituted of a substation 2 connected via a distribution line 4 and devices installed at a plurality of consumer residences 3. A signal synthesizing device 22 receives power carrier waves transformed from a transformer 21, superimposes signal waves including a substation ID and time on the power carrier waves received, and transmits the superimposed waves to a bus bar 23. The superimposed waves are transmitted to the distribution line 4 via the bus bar 23 and distribution line breakers 24. Signal separation devices 31 separate the power carrier waves and the signal waves from the waves received from the distribution line 4 and transmit the signal waves. Distributed power breaking devices 35 receive the signal waves from the signal separation device 31 and gives instruction to open the circuit of contactors 33 when neither substation ID nor time is included in the received signal waves. The distributed power supplies 34 are interrupted by opening the circuit when the contactors 33 receives the instruction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a transfer interrupt system for a distributed power source.

In recent years, distributed power sources such as solar power generation and wind power generation are becoming popular. Here, when distributed power sources are widely spread, there is a concern that when an accident occurs in a distribution system to which they are connected, the accident may be expanded due to the distributed power source becoming a single state. Therefore, an isolated operation prevention device and a transfer interruption device have been proposed as a method of stopping the distributed power supply.
JP 2002-27671 A

  However, the isolated operation prevention device is currently under research and development in order to cope with the problem of erroneously detecting an accident due to interference between signals transmitted by a large number of devices. In addition, the transfer cut-off device can reliably stop the distributed power supply by receiving the transfer cut-off signal when a distribution system fault occurs, but it is necessary to secure a communication line for transmitting the transfer cut-off signal. It is.

  Therefore, Patent Document 1 discloses an isolated operation prevention device that does not require the installation of a communication line. This is a technique for injecting a carrier signal into a bus of a substation and checking the presence or absence of the carrier signal in the distributed power supply device, and disconnecting from the distribution system if reception is not possible. However, in this technique, since it is not known whether the received carrier signal is from the original substation, there is a possibility that it cannot be cut off even if the distribution system is abnormal.

  The present invention has been made in view of the above problems, and its main object is to quickly and reliably shut off a distributed power source when an accident occurs in a distribution system without using a communication line. is there.

  In order to solve the above-mentioned problem, the present invention is a distributed power supply transfer cutoff system, which superimposes a signal wave including a substation ID on a received power carrier wave and transmits the superimposed wave to a distribution system. When the substation ID is not included in the combining means, the signal separating means for separating the power carrier wave and the signal wave from the received wave from the distribution system, and the signal wave separated by the signal separating means And a distributed power supply cutoff means for cutting off the distributed power supply.

  According to this configuration, since it is confirmed whether or not the original substation ID is included in the signal wave, an accident occurs in the distribution system, and the power from the substation is no longer conveyed, or the distribution system Even if power is mistakenly transferred from other than the substation due to the abnormality, the distributed power supply can be stopped quickly and reliably without using a communication line.

  In addition, the present invention is a distributed power transfer cutoff system, wherein the signal synthesis unit superimposes a signal wave including time in addition to the substation ID on the power carrier wave, And the distributed power shutoff means shuts off the distributed power supply when the time is not included in the signal wave separated by the signal separating means in addition to the above case. And

  According to this configuration, since it is confirmed whether or not the real time is included in the signal wave, the distributed power source can be stopped more reliably when the original power is not carried.

  The present invention is also a distributed power supply transfer cutoff system, wherein the distributed power cutoff means uses the time when the signal wave separated by the signal separation means includes the time. The time correction of the clock is performed.

  According to this configuration, it is possible to effectively use the time included in the signal wave received by the distributed power cutoff unit.

  In addition, the problems disclosed in the present application and the solutions thereof will be clarified by the column of the best mode for carrying out the invention and the drawings.

  ADVANTAGE OF THE INVENTION According to this invention, when an accident generate | occur | produces in a power distribution system, without using a communication line, it can interrupt | block a distributed power supply quickly and reliably.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. In the distributed power supply transfer cut-off system according to the embodiment of the present invention, the signal synthesis device superimposes the signal wave including the substation ID and the time on the power carrier and transmits it to the distribution system at the substation. At the customer's home, the signal separation device transmits the received wave from the distribution system separately to the power carrier wave and the signal wave, and the distributed power cut-off device includes the substation ID and time in the received signal wave. If not, the distributed power supply is cut off.

≪System configuration and overview≫
FIG. 1 is a diagram illustrating a configuration of a distributed power transfer cutoff system. The distributed power transfer interruption system 1 includes a substation 2 connected via a distribution line (distribution system) 4 and devices installed in a plurality of customer homes 3. In the substation 2, a transformer 21, a signal synthesizer (signal synthesizer) 22, a bus 23 and a distribution line breaker 24 are installed. The transformer 21 is a power device that receives a carrier wave of commercial power from a power plant and converts (transforms) an AC voltage. The signal synthesizer 22 is a device that receives the transformed power carrier wave from the transformer 21, superimposes a signal wave including the substation ID and time on the received power carrier wave, and transmits the superimposed wave.

  The substation ID is a code unique to the substation 2 and is used to specify a substation that is a supply source of power reaching the customer's house 3. Therefore, the received wave on which the signal wave including the substation ID of the substation 2 is not superimposed is not supplied from the substation 2. The time indicates real time and is set from a clock built in the signal synthesizer 22. Therefore, the received wave on which the signal wave including the real time is not superimposed is not supplied from the substation 2.

  The bus 23 is a power line that connects the signal synthesizer 22 and the distribution line breaker 24. The distribution line breaker 24 is a power device installed between the bus 23 and the distribution line 4, and is normally closed to connect the bus 23 and the distribution line 4, thereby supplying power to the distribution line 4. However, when an accident occurs in a power distribution system such as the distribution line 4, the power supply to the distribution line 4 is stopped by opening the power line 23 to cut off the space between the bus 23 and the distribution line 4. The superimposed wave transmitted by the signal synthesis device 22 is transmitted onto the distribution line 4 via the bus 23 and the distribution line breaker 24.

  In the customer's house 3, a signal separation device (signal separation means) 31, a load 32, a contactor 33, a distributed power supply 34 and a distributed power supply interruption device (distributed power supply interruption means) 35 are installed. The signal separation device 31 is a device that separates and transmits a power carrier wave and a signal wave from a reception wave from the distribution line 4. The load 32 is an electrical device that operates by receiving a power carrier wave from the signal separation device 31 or the distributed power source 34, and is, for example, various home appliances used in the customer's home 3.

  The contactor 33 is a switch installed between the signal separation device 31 and the load 32 and the distributed power source 34, and opens and closes according to an instruction from the distributed power shut-off device 35. The distributed power source 34 is a private power generation facility installed in the customer's house 3 and is a power source such as solar power generation or wind power generation. The distributed power shutoff device 35 receives the separated signal wave from the signal separation device 31 and instructs the contactor 33 to open the circuit when the received signal wave does not include the substation ID and time. . When the contactor 33 receives this instruction and opens the circuit, the distributed power source 34 is cut off.

<< Configuration and processing of signal synthesizer and signal separator >>
FIG. 2 is a diagram illustrating the configuration of the signal synthesis device and the signal separation device. FIG. 2A is a diagram illustrating a configuration of the signal synthesis device 22. The signal synthesizer 22 includes a signal generator 221 and an FM (Frequency Modulation) modulation modem 222. The signal generator 221 generates a signal wave including the substation ID and time and supplies the signal wave to the FM modulation modem 222. The substation ID is stored in a predetermined memory, and the time is supplied by a built-in clock.

  The FM modulation modem 222 receives a power carrier wave from the transformer 21 and generates a modulated wave (superimposed wave) by FM-modulating the received power carrier wave from the signal generator 221. Transmit to the bus 23. Here, the power of the signal wave transmitted by the signal generator 221 is sufficiently small compared to the power carrier wave, and the frequency fluctuation of the modulated wave transmitted by the FM modulation modem 222 affects the power quality of the commercial power. As small as possible. In addition, a frequency band of about several tens of kHz is used. This is because if the frequency is too low, it may be confused with harmonics, and if the frequency is too high, it may leak outside.

  FIG. 2B is a diagram illustrating the configuration of the signal separation device 31. The signal separation device 31 includes an FM demodulation modem 311. The FM demodulation modem 311 separates the power carrier wave and the signal wave from the modulated wave (received wave) from the distribution line 4 using the same frequency band as the FM modulation modem 222, and transmits the power carrier wave to the load 32. Then, the signal wave is transmitted to the distributed power shutoff device 35. Here, when the power supply from the substation 2 is stopped and there is no received wave, or when the received wave does not include the signal wave and the signal wave cannot be separated from the received wave, the signal wave is disconnected from the distributed power source. It cannot be transmitted to the device 35.

  The signal wave transmitted to the distributed power cut-off device 35 is used for determination regarding the transfer cut-off of the distributed power supply 34 and time correction of the built-in clock of the distributed power cut-off device 35. The built-in clock of the distributed power shutoff device 35 is used, for example, to add time data when storing the state change of the distributed power supply 34 as a history, and the stored history data is displayed on a monitor as needed. Is done.

≪Distributed power shutoff device processing≫
FIG. 3 is a flowchart showing processing of the distributed power shutoff device. First, the distributed power shutoff device 35 determines whether or not the signal wave received from the signal separation device 31 includes the substation ID of the substation 2 (step S301). This determination is to confirm whether or not the received wave of the signal separation device 31 is transmitted from the substation 2 that is the original power supply source.

  If the substation ID is included (Y in step S301), it is determined whether the received signal wave includes time (step S302). This determination is also to confirm whether or not the received wave of the signal separation device 31 is transmitted from the substation 2.

  If the time is included (Y in step S302), the distributed power shutoff device 35 corrects the time of the clock built in itself using the time (step S303). And it returns to determination of step S301. Note that the determinations in step S301 and step S302 are performed periodically with a predetermined time interval in order to detect that power is supplied but the power does not come from the original substation 2. Done.

  If the substation ID is not included in the signal wave received from the signal separation device 31 (N in step S301) or the time is not included in the received signal wave (N in step S302), the distributed power source The shut-off device 35 shuts off the distributed power source 34 (step S304). Specifically, the contactor 33 is instructed to open the circuit. In response to this instruction, the switch of the contactor 33 is opened, so that the distributed power source 34 is cut off.

  The distributed power shutoff device 35 determines whether or not the power distribution system has been restored (step S305), and if not restored (N in step S305), repeats the determination. When the restoration of the power distribution system is recognized from an operator input or the like (Y in step S305), the distributed power supply 34 is connected (step S306). Specifically, the contactor 33 is instructed to close the circuit. In response to this instruction, the switch of the contactor 33 is closed, so that the distributed power source 34 is connected. Then, it returns to determination of step S301.

  According to the embodiment of the present invention described above, since it is confirmed whether there is a signal wave in the received wave from the distribution line 4, an accident occurs in the distribution line 4 without using a communication line, When the electric power from the substation 2 is no longer conveyed, the distributed power source 34 can be quickly stopped. In addition, since it is confirmed whether or not the original substation 2 ID is included in the signal wave, even if power is mistakenly transmitted from other than the substation 2 due to an abnormality in the distribution line 4, it is surely distributed. The mold power supply 34 can be stopped. Then, since it is confirmed whether or not the time is included in the signal wave, the distributed power source 34 can be surely stopped when the original power is not carried. In addition, the time included in the signal wave can be effectively used for correction of the internal clock.

  According to the above, it is not necessary to examine the problem of interference in the isolated operation prevention device and the problem of securing the communication line in the transfer blocking device, and the signal synthesis device 22 is installed in the substation 2 and the signal separation device is installed in the customer's home 3. By installing 31 and using a signal wave including a substation ID and time, the distributed power source 34 can be shut off quickly and reliably when an accident occurs in the distribution line 4.

Although the best mode for carrying out the present invention has been described above, the above embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and equivalents thereof are also included in the present invention. For example, the following embodiments can be considered.
(1) In the above embodiment, the signal wave including the substation ID and the time is used. However, other data may be added to the signal wave.
(2) The original substation 2 from which the customer's house 3 receives power supply is not always the same, and may vary depending on the time zone. In this case, when the distributed power shutoff device 35 checks the substation ID included in the signal wave received from the signal separation device 31, at least one substation out of the plurality of substations 2 to which power is supplied. You may make it confirm whether it corresponds with ID, and you may make it compare with substation ID according to a time slot | zone.

It is a figure which shows the structure of the transfer interruption | blocking system for distributed power supplies. It is a figure which shows the structure of a signal synthesizer and a signal separator, (a) shows the structure of the signal synthesizer 22, (b) shows the structure of the signal separator 31. It is a flowchart which shows the process of a distributed type | mold power supply cutoff device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transfer interruption system for distributed power sources 2 Substation 21 Transformer 22 Signal synthesizer (Signal synthesizer)
221 Signal generator 222 FM modulation modem 23 Bus 24 Distribution line breaker 3 Customer's house 31 Signal separation device (signal separation means)
311 FM demodulation modem 32 Load 33 Contactor 34 Distributed power source 35 Distributed power shut-off device (Distributed power shut-off means)
4 Distribution lines (distribution system)

Claims (3)

Signal combining means for superimposing a signal wave including a substation ID on the received power carrier wave and transmitting the superimposed wave to the distribution system;
A signal separating means for separating a power carrier wave and a signal wave from a received wave from the distribution system;
A distributed power supply shut-off means for shutting down a distributed power supply when the substation ID is not included in the signal wave separated by the signal separation means;
A transfer interruption system for a distributed power source, comprising: It is the transfer interruption | blocking system for distributed power supplies of Claim 1, Comprising:
The signal synthesizing unit superimposes a signal wave including time in addition to the substation ID on the power carrier wave, and transmits the superimposed wave.
In addition to the above case, the distributed power supply cutoff means cuts off the distributed power supply even when the time is not included in the signal wave separated by the signal separation means. Type transfer stop system. It is the transfer interruption | blocking system for distributed power supplies of Claim 2, Comprising:
The distributed power shut-off means, when the time is included in the signal wave separated by the signal separation means, performs time correction of a clock using the time. Transfer blocking system.

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