JP2009219247A - Standalone operation preventing system and control apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly and reliably release a power application state in an optional section, for safety of a worker, even if the optional section of a distribution system is forcibly disconnected due to fire of a residence or the like, and its state is not determined as an accident. <P>SOLUTION: A standalone operation preventing system 100 includes an open detecting part 202 which detects opening of power feeding switches 130B and 130F, and a command transmission part 204 which, upon detecting opening of all power feeding switches in a section, transmits a disconnection command to a distributed switch 130G in a power feeding region 170 of the section. The distributed switch includes a command accepting part 206 which opens connection between the power feeding region of the section and a distributed type power supply 150 based on the disconnection command. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an isolated operation prevention system and a control device that prevent an isolated operation of a distributed power source.

  In recent years, in parallel with electric power supplied from distribution facilities of electric power companies such as distribution substations, electric power companies and consumers other than electric power companies themselves generate electric power to effectively use resources. A power source that generates such electric power is particularly called a distributed power source (DG), and includes various power sources such as a high-voltage output private generator, a low-voltage output solar cell, and a fuel cell.

  In a distribution system provided by an electrician, power transmission by the high-voltage distribution line is stopped (power failure) in the event of a short circuit or ground fault. However, if a distributed power source is connected to the high-voltage distribution line, A reverse power flow occurs, the power-charging state is maintained, and the accident point is hindered.

  Therefore, the remote shutoff control device constantly acquires and stores the position information of the distributed power source and the switch state information in the system, and based on this stored information, each distributed power source has which distribution line at which substation. Is known to individually identify whether it is under the power supply (power supply area) and selectively transmit a transfer cut-off control signal only to a distributed power source that is a transfer cut-off target when an accident occurs in the system (For example, patent document 1).

  By using this technology, it became possible to disconnect the distributed power source from the high-voltage distribution line. However, in recent years when distributed power sources are increasing and diversifying, it is not feasible for a remote cutoff control device to monitor all of the distributed power sources and directly stop them.

  To solve this problem, when a ground fault or short-circuit accident is detected, the switch of the low-voltage distribution line is opened, then the resistance short-circuit is closed and the two phases of the low-voltage distribution line are short-circuited. A technique for stopping the power supply is disclosed (for example, Patent Document 2). In addition, the protection relay captures the detection output of the current transformer and transformer, and monitors the occurrence of system faults. When an accident is detected, it outputs a start signal to prevent isolated operation in response to the fault detection. A technique for opening and forcibly shorting a circuit breaker upstream of a power supply is also disclosed (for example, Patent Document 3).

Furthermore, it is possible to avoid isolated operation by mounting a passive isolated operation prevention device or an active isolated operation prevention device on the distributed power supply itself. A passive type isolated operation prevention device is a device that detects a change in load or frequency due to the distribution system being disconnected and stops the distributed power supply itself. This device applies a small amount of bias in the upward direction (one direction) and detects a change in frequency or impedance when the power distribution system is disconnected from the control stable state, thereby stopping the distributed power supply itself.
JP 2005-198446 A JP-A-2005-341666 JP 2007-037354 A

  By the way, when an arbitrary section of the power distribution system is urgently separated in order to ensure the safety of workers in a house fire or the like, a switch connected to the section is temporarily opened by remote control or field operation. However, since the conventional technology as described above that opens the switch after detecting a ground fault or a short-circuit accident cannot detect such a forced opening operation of the switch, a distributed power Even if was connected, the distributed power source could not be separated from the distribution system.

  Under such circumstances, it is necessary to rely on, for example, passive isolated operation prevention devices mounted on the distributed power supply, but the load generated by the distributed power supply and the load on the customer connected to the low-voltage distribution line Are in balance, in other words, when the power generation and load are balanced within a single system, or when there is little change in the amount of electricity when a single system is generated, It may not be possible to reliably detect that the operation is continued, and the isolated operation prevention device does not operate normally. If it does so, the distributed power supply which did not receive operation stop command will continue an operation | movement, and an applied state will be maintained in a low voltage distribution line. The voltage of such a distributed power source is boosted to a high-voltage distribution line via a pole transformer and becomes an excessive voltage, and an operator can receive an electric shock even though the section switch in any section is open. Sex will occur.

  Also, in the active type independent operation preventing device, when a plurality of units are connected to the same line, it becomes difficult to detect the isolated operation because the active signals interfere with each other.

  In view of such a problem, the present invention promptly determines the state of power distribution in an arbitrary section even when an arbitrary section of the distribution system is forcibly divided due to a house fire or the like and the situation is not determined to be an accident. An object of the present invention is to provide an isolated operation prevention system and a control device that can be surely released to ensure the safety of an operator.

  In order to solve the above-described problem, a typical configuration according to the present invention includes one or a plurality of power supply switches that open and close power supply from the system power supply to the section in any section that receives power from the system power supply. A distributed power source in the power feeding area of the section, a distributed switch capable of separating the distributed power source from the power feeding area of the section, and a control device capable of individually controlling the power switch and the switching state of the distributed switch. An isolated operation prevention system for preventing isolated operation of a distributed power source, wherein the control device detects an open detection unit for detecting the opening of the power supply switch, and detects that all the power supply switches in the section are open. A command transmission unit that transmits a disconnection command to the distributed switch in the power supply region, and the distributed switch opens a connection between the power supply region of the section and the distributed power source according to the split command Specially equipped with To. Here, the isolated operation means that the distribution state is maintained by the continuous operation of the distributed power source in the distribution system separated from the distribution facility (system power source) of the electric power company.

  In the present invention, the control device grasps that the open / close state of one or a plurality of power supply switches that open and close the power supply from the system power supply to the target section is an open state, so that the section is an electric utility. Recognize that the person is disconnected from the distribution system (distribution equipment). Therefore, regardless of the cause of the opening of the power supply switch, the disconnection command is transmitted to the distributed switch connected upstream of the distributed power source, and the power supply state of the section surrounded by the power supply switch and the distributed switch Can be quickly and reliably released, and the safety of the operator can be improved.

  The command receiving unit may further short-circuit between the lines on the distributed power source side according to the division command. Once the distributed switch is opened, all of the distributed power supplies under it must be stopped when the power is restored (when power is turned on again). With such a configuration that short-circuits the lines on the distributed power supply side, the load on the distributed power supply can be rapidly increased, and the balance of supply and demand between the power supply and the load can be biased, and the number of distributed power supplies is very large. However, it is possible to reliably stop the distributed power supply regardless of the number or type.

  Another representative configuration according to the present invention includes one or a plurality of power supply switches that open and close power supply from the system power supply to the section in any section that receives power from the system power supply, and a power supply area of the section. A distributed power source comprising: a distributed power source; a line short circuit located upstream of the distributed power source; and a control device capable of individually controlling a switching state of the power supply switch and a short circuit state of the line short circuit. In the isolated operation prevention system, the control device is in the power supply area of the section when detecting the open detection unit for detecting the opening of the power supply switch and the opening of all the power supply switches in the section. A command transmission unit that transmits a division command to the line short-circuit, and the line short-circuit short-circuits between the lines of the distribution line according to the division command.

  Here, the distributed power source is connected to the power supply region of the section directly or through a transformer or the like without using the above-described distributed switch. Therefore, the transmission target of the division command is a line short circuit located upstream of the distributed switch, and the line short circuit performs a short circuit between the lines.

  Another representative configuration according to the present invention includes one or a plurality of power supply switches for opening and closing power supply from the system power supply to the section in an arbitrary section for receiving power from the system power supply, and a power supply area of the section Is a control device capable of individually controlling the open / closed state of a distributed switch that can decouple the distributed power source from the power supply area of the section, and an open detection unit that detects the opening of the power supply switch, and all the switches in the section When the opening of the power supply switch is detected, the distributed switch includes a command transmission unit that transmits a disconnection command for opening a connection between at least the power supply region of the section and the distributed power source.

  Another representative configuration according to the present invention includes an open / close state of one or a plurality of power supply switches for opening and closing power supply from the system power supply to the section in any section that receives power from the system power supply, and a section Is a control device capable of individually controlling the short-circuit state of the line short circuit located upstream of the distributed power source in the power supply area, and an open detection unit that detects the open of the power supply switch, and all of the sections in the section When the opening of the power supply switch is detected, a command transmission unit that transmits a disconnection command for short-circuiting between the lines of the distribution line is provided to the line short-circuiting device.

  The component corresponding to the technical idea in the isolated operation prevention system described above and the description thereof can be applied to the control device.

  As described above, according to the present invention, even when an arbitrary section of the power distribution system is forcibly divided due to a house fire or the like and the situation is not determined to be an accident, the electric power distribution state of the arbitrary section can be quickly and It is possible to release it reliably and to ensure the safety of the operator.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  For example, in the event of a house fire, as part of fire fighting work support, any section of the distribution system may be used to temporarily de-energize the distribution system that passes through the area where the fire is occurring. May be urgently separated. This is done by temporarily opening a switch connected to the section by remote control or field operation. However, since the output of the distributed power source connected to the power distribution system cannot be stopped by opening the switch, there is a possibility that the power distribution state is maintained. If such a charge state (single operation state) remains, there is a risk of electric shocks from firefighters and other workers who do not know that it is in the charge state, and that the charge state will continue. In some cases, the distributed power supply itself may be damaged.

  In the isolated operation prevention system of this embodiment, when any section of the power distribution system is forcibly divided due to such a house fire or the like, the power distribution state of this arbitrary section is quickly and reliably released, The purpose is to ensure the safety of the elderly.

(First embodiment: Isolated operation prevention system 100)
FIG. 1 is an explanatory diagram showing a schematic configuration of the isolated operation prevention system 100. Here, the isolated operation prevention system 100 includes a distribution substation 110, a distribution line 120 (a high-voltage distribution line 120A, a low-voltage distribution line 120B), and a switch 130 (section switches 130A, 130B, 130C, 130D, and 130E, System switch 130F, switch with short-circuit function (group breaker) 130G), pole transformer 140, distributed power source 150, and controller 160.

  The distribution substation 110 transforms the power received from the bus 112 into a 6.6 kV three-phase AC 50/60 Hz by the distribution transformer 114 and distributes the power to the high-voltage distribution line 120 of each distribution system through the substation circuit breaker 116. ing. The high-voltage distribution line 120A is composed of parallel lines (feeders) (A1) and (A2) that branch from the distribution transformer 114 and spread radially, and are connected to other parallel lines (B) through the connection switch 130F. can do.

  The switch 130 relays the distribution lines 120 on the distribution system, and opens and closes the connections of the distribution lines 120. In the following embodiments, the switch 130 is referred to as a power supply switch or a distributed switch depending on its function. The power supply switch indicates a switch that opens and closes the power supply from the system power supply to any section, and the distributed switch is connected upstream of the distributed power supply and can divide the distributed power supply from the power supply area of any section A simple switch. Such a power supply switch and a distributed switch are dynamically defined according to a difference in a target section. In order to facilitate understanding, here, the division switch 130B and the interconnection switch 130F that can receive power from the system power supply are used as the power supply switch, and the switch with short circuit function 130G provided upstream of the distributed power supply 150 is distributed. Use a switch. Here, in FIG. 1 and the following figures, black fill indicates a closed circuit of the switch 130, and white fill indicates open of the switch 130.

  In addition, the power supply area of any section described above refers to all areas where power can be supplied when the power supply switch is closed, and specifically includes a section closed by the power supply switch and a section downstream thereof. Is done. Therefore, in the example of FIG. 1, the power supply area of the section by the power supply switches 130B and 130F indicates the area 170, and when the power supply switch is the section switches 130A and 130B, the area 180 indicates the area 180.

  The pole transformer 140 converts the power of the high-voltage distribution line 120A into the power of the low-voltage distribution line 120B. The distributed power source 150 includes various power sources such as a private power generator, a solar cell, and a fuel cell, and can supply power to the low-voltage distribution line 120B in parallel with the power supplied from the distribution facility of the electric power company. . The control device 160 is connected to the substation circuit breaker 116 and the switch 130 in the distribution substation 110 and individually controls the open / close state of the switch 130. Here, the control device 160 and the switch 130 are connected via a communication network 162 constituted by an ISDN (Integrated Services Digital Network) line, the Internet, a dedicated line, a wireless communication line and the like, which are indicated by a one-dot chain line in FIG. Although the example connected is given, the control apparatus 160 can also be installed adjacent to the switch 130, or can be integrally formed, and can take various installation modes.

  By the way, for example, when an accident occurs between the section switch 130B and the interconnection switch 130F, the protection relay 118 in the distribution substation 110 is activated, the substation breaker 116 trips, and the parallel line ( The power distribution in A1) is stopped. Such power failure information is also distributed to the control device 160, and the control device 160 opens the section switches 130A and 130B. Thus, the section where the accident occurred can be disconnected from the power distribution system. However, the protection relay 118 cannot detect a forced opening operation of the switch 130 in a house fire or the like. Therefore, a means for detecting such a forced opening operation is required separately from the accident detection.

  FIG. 2 is a functional block diagram illustrating functions of the power supply switches 130B and 130F, the control device 160, and the distributed switch 130G in the present embodiment. The switches 130B and 130F are configured to include the switching transmission unit 200, the control device 160 is configured to include the opening detection unit 202 and the command transmission unit 204, and the distributed switch 130G includes the command reception unit 206. Consists of including.

  The switching transmission / reception unit 200 of the switch 130 transmits switching information such as whether the switch is in a closed state or an open state to the control device 160.

  The open detection unit 202 of the control device 160 always acquires the open state of the switch 130 regularly and distributes power to the section in any section that receives power from the system power source, here, the distribution substation 110. By detecting that all the power supply switches 130B and 130F that open and close the power supply from the substation 110 are opened (logical product), the power supply region 170 in the section surrounded by the power supply switches 130B and 130F For example, it is grasped that the distribution substation 110 is disconnected due to a fire or the like.

  When the command transmission unit 204 of the control device 160 detects the opening of all the power supply switches in the section, here, the power supply switches 130B and 130F, the command transmission unit 204 transmits a disconnection command to the distributed switch 130G in the power supply region 170 of the section.

  The command receiving unit 206 of the distributed switch 130G opens the connection in response to the disconnection command from the control device 160 if the connection with the distributed power source 150 is still closed.

  Thus, in the present embodiment, the control device 160 grasps that the open / close state of one or more power supply switches that open and close the power supply from the system power supply to the target section is an open state. Recognize that the section is disconnected from the distribution system (distribution equipment) of the electric utility. Therefore, regardless of the cause of the opening of the power supply switch, a disconnection command is transmitted to the distributed switch 130 connected upstream of the distributed power supply 150, and the section surrounded by the power supply switch and the distributed switch 130 is transmitted. It is possible to quickly and surely release the power-applied state, and it is possible to improve the safety of the worker.

  Further, the command receiving unit 206 forcibly shorts all three phases or any two phases between the lines on the distributed power source side in response to a division command (including a forced short circuit signal). With such a configuration in which the lines on the distributed power source side are short-circuited, the load on the distributed power source 150 can be rapidly increased, and the balance of supply and demand between the power source and the load can be biased. Even when, for example, several hundred or more distributed power sources 150 are connected to the power supply region 170 of the section, the independent operation of the distributed power source 150 can be reliably prevented regardless of the number or type. Is possible. Further, it is not necessary to stop the distributed power source 150 again at the time of power recovery (at the time of re-input).

(Second embodiment: Isolated operation prevention system 300)
In the first embodiment described above, the distributed power source 150 is connected to the parallel line (A1) via the distributed switch 130G. However, in the second embodiment, the distributed power source 150 is connected to the pole transformer 140. Is directly connected to the parallel line (A1).

  FIG. 3 is an explanatory diagram showing the configuration of the isolated operation prevention system 300. The isolated operation prevention system 300 includes a distribution substation 110, a distribution line 120 (a high-voltage distribution line 120A, a low-voltage distribution line 120B), a switch 130 (a section switch 130A, 130B, 130C, 130D, 130E, an interconnected switch. 130F), pole transformer 140, distributed power source 150, control device 160, and line short circuit 310. Distribution substation 110, distribution line 120 (high-voltage distribution line 120A, low-voltage distribution line 120B), switch 130, pole transformer 140, distributed power supply already described as the components in the first embodiment Since 150 and the control device 160 have substantially the same functions, redundant description will be omitted, and here, the line short circuit 310 having a different configuration will be mainly described.

  FIG. 4 is a functional block diagram illustrating functions of the switch 130, the control device 160, and the line short-circuiting device 310 in the isolated operation prevention system 300. Here, the power supply switches 130B and 130F are configured to include the switching transmission / reception unit 200, the control device 160 is configured to include the opening detection unit 202 and the command transmission unit 204, and the line short circuit 310 is A command receiving unit 306 is included. Here, although the power supply switch 130B and the line short circuit 310 that are disposed in proximity are described separately, it goes without saying that the power supply switch 130B and the line short circuit 310 can be integrally formed. . In the first embodiment, the distributed switch 130G performs the separation from the distributed power source 150 and the stop of the distributed power source 150. Here, the distributed power source 150 is directly connected via the pole transformer 140. Since it is connected to the parallel line (A1), the line short circuit 310 performs the operation of the distributed switch 130G.

  The open detection unit 202 of the control device 160 constantly acquires the open state of the switch 130 at regular intervals, and receives power from the distribution substation 110 from the distribution substation 110 to the corresponding section in any section that receives power from the distribution substation 110. It is detected that all of the power supply switches 130B and 130F that open and close the power supply are opened.

  When the command transmission unit 204 of the control device 160 detects the opening of all the power supply switches in the section, here, the power supply switches 130B and 130F, the command transmission unit 204 transmits a disconnection command to the line short circuit 310 in the power supply region 170 of the section. .

  And the command reception part 306 of the line short circuit 310 short-circuits between the lines of a distribution line according to the division | segmentation instruction | command from the control apparatus 160. FIG.

  In the present embodiment, since the power supply switches 130B and 130F located upstream of the distributed power supply 150 have already been disconnected, the power supply from the distribution substation 110 that is the system power supply has already been cut off. Therefore, the line short circuit 310 performs only a short circuit between the lines on the distributed power source side. With the configuration in which the lines on the distributed power supply side are short-circuited, as in the first embodiment, the load on the distributed power supply 150 is rapidly increased, the balance between supply and demand of the power supply and the load is biased, and the number of distributed power supplies Regardless, it is possible to reliably prevent isolated operation of the distributed power source 150.

  Summarizing the features of the present application through the first embodiment and the second embodiment, (1) the control device 160 monitors the open state of the power supply switch and supplies power to open and close the power supply from the system power supply to an arbitrary section. When all the switches are in the open state, it is considered that the arbitrary section is divided by the forcible operation, and (2) the distributed power supply 150 under the arbitrary section opens the distributed switch 130 upstream. And it stops by the short circuit or the short circuit of the line short circuit 310, and the power-applying state of the distributed power source 150 to an arbitrary section is prevented.

  In this way, when the fire occurrence section is separated from the power distribution system for fire fighting support such as a house fire, the distributed power supply 150 is also stopped immediately after the separation, and the state of power distribution in this fire occurrence section is quickly and surely released. Safety can be achieved. However, since a large current due to a large inertia flows in the short circuit of the line short circuit 310 of the second embodiment, the continuous range of the distributed power source 150 is reduced to a small area through the distributed switch as in the first embodiment. It is good to divide into two and short-circuit at the position of the dispersion switch.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  For example, in the above-described embodiment, the single operation of the distributed power source 150 is prevented by giving an example of the forced operation of the switch 130 due to a fire or the like. However, the present invention is not limited to this, and an accident search when an accident occurs Even if the distribution line is stressed due to landslide or the like but is not broken, it is not judged as an accident, but the same effect can be obtained under various situations where the switch 130 needs to be opened.

  The present invention is applicable to an isolated operation prevention system and a control device that prevent an isolated operation of a distributed power source.

It is explanatory drawing which shows the schematic structure of the isolated operation prevention system in 1st Embodiment. It is a functional block diagram showing the function of each component in the first embodiment. It is explanatory drawing which shows the structure of the isolated operation prevention system in 2nd Embodiment. It is the functional block diagram which showed the function of each component in 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100, 300 ... Isolated operation prevention system 110 ... Distribution substation 120 ... Distribution line 130 ... Switch 150 ... Distributed power supply 160 ... Control apparatus 200 ... Opening / closing transmission part 202 ... Opening detection part 204 ... Command transmission part 206, 306 ... Command receiving unit 306 ... line short circuit

Claims (5)

One or a plurality of power supply switches for opening and closing power supply from the system power supply to the section in an arbitrary section for receiving power from the system power supply, a distributed power supply in the power supply area of the section, and the distributed power supply A distributed switch that can be separated from the power supply region of the section, and a control device that can individually control the open / closed state of the power supply switch and the distributed switch, A driving prevention system,
The controller is
An opening detection unit for detecting opening of the power supply switch;
When detecting the opening of all the power supply switches in the section, a command transmission unit that transmits a split command to the distributed switches in the power supply area of the section;
With
The said distributed switch is provided with the command reception part which open | releases the connection of the electric power feeding area | region of the said area and the said distributed power supply according to the said division | segmentation instruction | command, The isolated operation prevention system characterized by the above-mentioned.   2. The isolated operation prevention system according to claim 1, wherein the command receiving unit further short-circuits the lines on the distributed power source side according to the division command. One or a plurality of power supply switches for opening and closing power supply from the system power supply to the section in an arbitrary section for receiving power from the system power supply, a distributed power supply in the power supply area of the section, and the distributed power supply And a control device capable of individually controlling the open / close state of the power supply switch and the short-circuit state of the line short circuit to prevent isolated operation of the distributed power source. An isolated operation prevention system,
The controller is
An opening detection unit for detecting opening of the power supply switch;
When detecting the opening of all the power supply switches in the section, a command transmission unit that transmits a disconnection command to the line short circuit in the power supply region of the section;
With
The said line | wire short circuit device short-circuits between the lines of a distribution line according to the said division | segmentation instruction | command, The independent operation prevention system characterized by the above-mentioned. In any section that receives power from the system power supply, one or more power supply switches that open and close the power supply from the system power supply to the section, and a distributed power source in the power supply area of the section A control device capable of individually controlling the open / closed state of a distributed switch that can be separated from the area,
An opening detection unit for detecting opening of the power supply switch;
When detecting the opening of all the power supply switches in the section, a command transmission unit that transmits a disconnection command to open the connection between at least the power supply region of the section and the distributed power source to the distributed switch,
A control device comprising: In any section that receives power from the system power supply, the open / close state of one or more power supply switches that open and close the power supply from the system power supply to the section, and upstream of the distributed power supply in the power supply area of the section A control device capable of individually controlling the short-circuit state of the line short-circuit located at
An opening detection unit for detecting opening of the power supply switch;
When detecting the opening of all the power supply switches in the section, a command transmission unit that transmits a disconnection command to short-circuit between the lines of the distribution line to the line short circuit,
A control device comprising:

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