JP7251213B2 - Bank reverse power flow suppression system and method - Google Patents

Description

The present invention relates to a system for suppressing the occurrence of reverse power flow when an accident occurs in a power system to which distributed power sources are connected, and a method for suppressing the occurrence of bank reverse power flow using the system. The present invention relates to a bank reverse power flow suppression system and a bank reverse power flow suppression method using the same, which can safely and efficiently restore work even if the system is not

In our corporate activities and in our daily lives, electric energy is now an indispensable energy because of its ease of handling, etc., and its application area is expanding even now. Especially in recent years, the expansion trend has been strengthened, and products using electric energy are beginning to appear one after another in fields where electric energy has not been used so far. For example, electric vehicles and electric construction machines that can be charged at home are examples. In this way, our society is rapidly changing to one centered on electric energy, and it is believed that the demand for electric power will further increase in the future.

Against this background, demand from consumers who want electric power companies to "build a stable power supply system" is increasing more than ever. There are various ideas for what this "stable power supply system" should be, but one of them is to carry out restoration work accurately, quickly, and safely even in the event of an accident on the power system. It is mentioned that it is a system that can be done. With this kind of system, even in the event of a power outage due to an accident, it would be possible to complete the restoration work quickly and safely while minimizing further power outage damage, while minimizing the negative impact on our lives. can be reduced to

Here, regarding the recovery method in the event of an accident on the power system, in general, in order to suppress the spread of damage to sound sections in the power system, work to detach it. Specifically, an operation is performed to stop the power supply from the power plant to the location where the accident occurred by, for example, shutting off equipment (circuit breaker, etc.) located on the higher voltage side than the location of the accident. This operation prevents the adverse effects of the accident from spreading to sound areas, and allows workers to safely perform restoration work on the site where the accident occurred.

Such restoration work is performed on conventional power systems, where power is one-way from power plants to power consumers. However, with the increasing demand for electricity in recent years, the lines of power systems have become more complex. That in itself is becoming difficult. Furthermore, recently, power systems have emerged in which many small-scale distributed power sources are connected to distribution lines. have to consider.

Reverse power flow means that in a power system in which distributed power sources are connected to distribution lines, the power of the distributed power sources flows toward the bus line side. Such reverse power flow occurs when the power supply from an upstream power plant stops due to an accident, etc., or when the distributed power source is solar power generation, and the amount of power generated becomes excessive due to good weather. known to occur from time to time. Such reverse power flow may even flow to distribution transformers (a group of one or more transformers is particularly called a "bank"), and such reverse power flow is particularly called "bank reverse power flow".

A reverse power flow (including a bank reverse power flow) from distributed power sources will be briefly described with reference to FIG. FIG. 9 exemplifies a power system that supplies electric power from a power plant to consumers (households, solar power plants, factories) via a bank. b) shows the state when an accident occurs between the bank and the power plant, and FIG. 9(c) shows the state when the bank fails.

In the normal state shown in FIG. 9(a), the load of power from the power plant is adjusted to exceed the load of the photovoltaic power plant. There is only forward flow and no reverse power flow occurs. However, if an accident occurs between the bank and the power plant as shown in Fig. 9(b) and the power supply from the power plant is stopped for restoration work, the power load from the solar power plant will become relatively large. This directs current flow from the PV plant to other consumers and then to the bank.

It is known that the bank reverse power flow that occurs in this manner causes damage to the bank, and if the bank reverse power flow damages the bank, it is inevitable that the recovery period will be prolonged. Therefore, when a bank reverse power flow occurs, the electric power company must disconnect the solar power plant that is the cause of the bank reverse power flow from the power system as soon as possible to stop the bank reverse power flow. Also, when the bank fails and the line connecting the bank and the distribution line is cut off as shown in Fig. 9(c), the power load from the photovoltaic power plant causes the current to flow to other consumers. become. Even in such a case, there is a possibility of inducing failures in the electric equipment of the consumer, and the electric power company must immediately disconnect the photovoltaic power plant that is the cause from the electric power system.

In the power system having the configuration shown in FIG. 9, the source of the bank reverse power flow can be easily identified, and there is no problem in preventing the bank reverse power flow. However, in most of the actual electric power systems, a plurality of distributed power sources, which are sources of bank reverse power flow, are connected, and busbars, distribution lines, and the like are connected in a complicated manner. When an accident occurs in such an actual power system, power supply to the accident site is first stopped. Then, after ascertaining the blackout section based on the connection status of equipment in the power system, which distributed power source will generate the bank reverse power flow is identified by manual calculation, etc., and the corresponding distributed power source is distributed. disconnected from the power line.

As described above, power systems have become so complex and diversified that it is necessary to consider reverse power flow. In the worst case, it is fully expected that the worker himself will be injured. In addition, in modern society, where jobs are becoming fluid and the birthrate is declining and the population is aging, the number of experienced workers themselves is decreasing.
Against this background, even in the event of a complicated power system accident, regardless of the level of experience, the establishment of a method to safely and quickly restore the location where the accident occurred while suppressing bank reverse power flow. is urgent.

Here, in order to support recovery from an accident, recently, Patent Document 1 discloses a method of creating a slip on which equipment operation procedures to be used for recovery from an accident are described under the name of "Accident Recovery Management Method" by a computer. It is
In the recovery management method disclosed in Patent Document 1, signal data indicating the operating state is received by communication means from equipment on the power system, etc., and the signal data is compared with the data of the power system during normal times. It identifies the equipment that needs to be operated. Furthermore, this is a method in which the user creates a desired recovery procedure chart while prioritizing the operation of the specified equipment.

Patent document 1 also describes a system using the above method. This system includes a communication CPU for receiving equipment information of a power system by a communication means, a recovery guide CPU for deriving a recovery procedure based on signal data received from the communication CPU and user input data, and this recovery guide. It is composed of a guide display CPU that performs processing for outputting the results derived by the CPU to a display or the like, an input device such as a keyboard, and an output device such as a display.

The invention described in Patent Literature 1 has the effect of being able to check the power state at any timing because it is always connected to the power system. Then, when an abnormality such as an accident occurs in the power system, it is possible to easily create a recovery procedure chart while extracting candidates for circuit breakers that need to be operated and prioritizing the operation of circuit breakers. have

With these effects, even a distant power system can be constantly monitored if a communication environment is established, and if the communication range is expanded, it will be possible to manage multiple power systems. . Furthermore, in the event of an accident, a recovery procedure sheet suitable for the details of the accident can be easily created, regardless of the level of experience, reducing the risk of expanding damage and injuring workers due to incorrect operation of equipment. It is possible.

JP-A-6-178434

However, the invention described in Patent Document 1 does not presuppose that distributed power sources are connected, so there is a problem that it cannot be applied to prevent bank reverse power flow. In addition, in order to monitor the state of the power system, various capital investments are required other than installing this system, such as installing signal detectors and building a communication environment, so anyone can easily install and use it. There was also the issue of not being Furthermore, since the contents of the recovery procedure chart can be adjusted according to the user's preference, it is possible that only those with a certain degree of experience can use it.

The present invention has been made in view of these problems, and its object is to prevent the occurrence of bank reverse power flow even by an unskilled person when an accident occurs in a power system to which distributed power sources are connected. To provide a bank reverse power flow suppression system and a bank reverse power flow suppression method using the same, which can efficiently perform restoration work.

In order to achieve the above object, a bank reverse power flow suppression system, which is a first invention, is provided in an electric power system in which a distributed power supply is connected to a secondary bus of a distribution transformer via a secondary side distribution line. A bank reverse power flow suppression system that prevents the occurrence of reverse power flow from distributed power sources to distribution transformers by interrupting the secondary side distribution line when an accident occurs on the upstream side of a secondary bus line. A secondary side distribution line based on the information input from the input unit for inputting information about the location and equipment existing on the power system, the storage unit storing the power system line data, and the information input from the input unit and the power system line data and a data processing unit for determining whether or not to cut off the secondary side distribution line when the first line connecting the secondary bus and the distribution transformer is not cut off. It is characterized by judging to cut off.

With such a bank reverse power flow suppression system, in a power system in which a distributed power supply is connected to the secondary bus of a distribution transformer via a secondary side distribution line, the accident location is upstream of the secondary bus. When information is input from the input section that the first line connecting the secondary bus and the distribution transformer is not cut off, the data processing section detects the distributed power source connected to the secondary bus as the source of the generation. It has the effect of instantaneously predicting the occurrence of bank reverse power flow. Then, based on this prediction result, the data processing unit also has the effect of creating and displaying a restraining procedure for prompting the user to cut off the power supply from the distributed power supply.

The bank reverse power flow suppression system, which is the second invention, is provided on the upstream side of the secondary bus in a power system in which a distributed power supply is connected to the secondary bus of a distribution transformer via a secondary side distribution line. A bank reverse power flow suppression system that prevents the occurrence of reverse power flow from distributed power sources to distribution transformers by shutting off the secondary side distribution line in the event of an accident. An input unit for inputting information about equipment existing in the storage unit, a storage unit storing power system line data, and whether or not the secondary side distribution line should be cut off based on the information and the power system line data input from the input unit and a data processing unit for determining whether the first line connecting the secondary bus and the distribution transformer is cut off and the secondary bus is supplied with power from another power system. It is characterized by determining to cut off the secondary side distribution line when it is determined that it is not.

With such a bank reverse power flow suppression system, in an electric power system in which a distributed power supply is connected to the secondary bus of the bank via a secondary side distribution line, the accident location is the secondary bus as in the case of the first invention. Information is received from the input unit that the first line that is upstream from the bus and connects the secondary bus and the distribution transformer is cut off and that the secondary bus is not supplied with power from another power system. When input, the data processing unit has the effect of instantaneously predicting the bank reverse power flow generated by the distributed power source connected to the secondary bus and the occurrence of reverse power flow in the secondary side distribution line. . Then, based on this prediction result, the data processing unit also has the effect of creating and displaying a restraining procedure for prompting cutoff of the power supply from the distributed power supply.

Next, in the bank reverse power flow suppression system, which is the third invention, the secondary side distributed power supply is connected to the secondary bus of the distribution transformer via the secondary side distribution line, and the tertiary power supply of the distribution transformer In a power system in which a tertiary distributed power supply is connected to a bus via a tertiary distribution line, when an accident occurs on the secondary bus, the tertiary distribution line is It is a bank reverse power flow suppression system that prevents the occurrence of reverse power flow from distributed power sources to distribution transformers. and a data processing unit that determines whether or not to cut off the secondary distribution line based on the information input from the input unit and the power system line data, the data processing unit comprising: It is characterized by determining to cut off the tertiary side distribution line when the second line connecting the tertiary bus and the distribution transformer is not cut off.

In such a bank reverse power flow suppression system, the secondary side distributed power supply is connected to the secondary bus of the distribution transformer through the secondary side distribution line, and the tertiary bus of the distribution transformer is connected to the secondary side distributed power supply. In a power system in which a tertiary distributed power supply is connected via a secondary distribution line, if an accident occurs on the secondary bus, the secondary line that connects the tertiary bus and the distribution transformer is cut off. When information is input from the input unit that it is not, the data processing unit has the effect of instantaneously predicting the occurrence of bank reverse power flow originating from the tertiary side distributed power supply connected to the tertiary bus. . Then, based on this prediction result, the data processing unit also has the effect of creating and displaying a restraining procedure for prompting cutoff of the power supply from the tertiary side distributed power supply.

In the bank reverse power flow suppression system of the fourth invention, the secondary side distributed power supply is connected to the secondary bus of the distribution transformer via the secondary side distribution line, and the tertiary bus of the distribution transformer is connected. In a power system in which a tertiary distributed power supply is connected to the tertiary distribution line, if an accident occurs on the tertiary bus, the secondary distribution line is cut off to restore the secondary distribution. It is a bank reverse power flow suppression system that prevents the occurrence of reverse power flow from a model power supply to a distribution transformer. and a data processing unit that determines whether or not to cut off the secondary distribution line based on the information input from the input unit and the power system line data. If the second line that connects the secondary bus and the distribution transformer is interrupted and the tertiary bus is not supplied with power from another power system, the decision is made to cut off the secondary side distribution line. characterized by

In such a bank reverse power flow suppression system, the secondary side distributed power supply is connected to the secondary bus of the distribution transformer through the secondary side distribution line, and the tertiary bus of the distribution transformer is connected to the secondary side distributed power supply. In a power system in which a tertiary distributed power source is connected via a secondary distribution line, if an accident occurs on the tertiary bus, the second line that connects the tertiary bus and the distribution transformer is cut off. and that the tertiary bus is not supplied with power from another power system, the data processing unit determines that the secondary side distributed power source connected to the secondary bus is the source of the generation. It has the effect of instantaneously predicting the occurrence of bank reverse power flow. Then, based on this prediction result, the data processing section creates a restraining procedure for prompting the user to cut off the power supply from the secondary side distributed power supply, and the procedure output section also has the effect of displaying this restraining procedure.

Furthermore, the bank reverse power flow suppression method, which is the fifth invention, is provided on the upstream side of the secondary bus in a power system in which a distributed power supply is connected to the secondary bus of a distribution transformer via a secondary side distribution line. A bank reverse power flow suppression method for preventing the occurrence of reverse power flow from a distributed power source to a distribution transformer by interrupting the secondary side distribution line when an accident occurs in a secondary bus and a distribution transformer The secondary side distribution line is cut off when the first line connecting the devices is not cut off.

With such a bank reverse power flow suppression method, in a power system in which a distributed power supply is connected to the secondary bus of a distribution transformer via a secondary side distribution line, the accident location is upstream of the secondary bus. If the first line that connects the secondary bus and the distribution transformer is not interrupted, it is determined that a bank reverse power flow originating from the distributed power supply connected to the secondary bus will occur. have an effect.

In addition, the bank reverse power flow suppression method, which is the sixth aspect of the invention, is provided upstream from the secondary bus in a power system in which a distributed power supply is connected to the secondary bus of a distribution transformer via a secondary side distribution line. A bank reverse power flow suppression method for preventing occurrence of reverse power flow from a distributed power source to a distribution transformer by interrupting a secondary side distribution line when an accident occurs in a secondary bus line and a distribution transformer. The secondary side distribution line is cut off when the first line connecting the transformers is cut off and the secondary bus is not supplied with power from another electric power system.

With such a bank reverse power flow suppression method, in a power system in which a distributed power supply is connected to the secondary bus of a distribution transformer via a secondary side distribution line, the accident location is upstream of the secondary bus. and is connected to the secondary bus when the first line connecting the secondary bus and the distribution transformer is interrupted and the secondary bus is not supplied with power from another power system It has the effect of judging that a bank reverse power flow originating from the power source and a reverse power flow in the secondary side distribution line occur.

In the bank reverse power flow suppression method of the seventh invention, the secondary side distributed power supply is connected to the secondary bus of the distribution transformer via the secondary side distribution line, and the tertiary bus of the distribution transformer is connected to the secondary side distributed power supply. In a power system in which a tertiary distributed power supply is connected to the tertiary side distribution line via a tertiary side distribution line, if an accident occurs on the secondary bus line, the tertiary side distribution line is cut off to prevent the tertiary side distribution A bank reverse power flow suppression method for preventing the occurrence of reverse power flow from a type power supply to a distribution transformer, and assuming that the second line connecting the tertiary bus and the distribution transformer is not interrupted, the tertiary It is characterized by cutting off the side distribution line.

With such a bank reverse power flow suppression method, the secondary side distributed power supply is connected to the secondary bus of the distribution transformer through the secondary side distribution line, and the tertiary bus of the distribution transformer is connected to the tertiary power supply. In a power system in which a tertiary side distributed power source is connected via a side distribution line, the accident location is on the secondary bus, and the second line connecting the tertiary bus and the distribution transformer is not cut off. In this case, it has the effect of determining that a bank reverse power flow originating from the tertiary side distributed power supply connected to the tertiary bus is generated.

Finally, in the bank reverse power flow suppression method of the eighth invention, the secondary side distributed power supply is connected to the secondary bus of the distribution transformer via the secondary side distribution line, and the tertiary power supply of the distribution transformer In a power system in which a tertiary-side distributed power source is connected to a bus via a tertiary-side distribution line, when an accident occurs on the tertiary-side bus, the secondary side is A bank reverse power flow suppression method for preventing occurrence of reverse power flow from a distributed power source to a distribution transformer, wherein a second line connecting a tertiary bus and a distribution transformer is cut off and another line is connected to the tertiary bus. The secondary side distribution line is cut off when power is not supplied from the power system.

With such a bank reverse power flow suppression method, the secondary side distributed power supply is connected to the secondary bus of the distribution transformer through the secondary side distribution line, and the tertiary bus of the distribution transformer is connected to the tertiary power supply. In a power system in which a tertiary distributed power source is connected via a side distribution line, the accident location is on the tertiary bus, the second line connecting the tertiary bus and the distribution transformer is interrupted, and The action of judging that a bank reverse power flow originating from the secondary-side distributed power supply connected to the secondary-side distribution line occurs when power is not supplied to the tertiary bus from another power system. have.

According to the bank reverse power flow suppression system of the first invention, the bank reverse power flow when the accident location is upstream of the secondary bus and the first line connecting the secondary bus and the distribution transformer is not cut off. It is possible to instantly predict the occurrence of , and easily output the suppression procedure. As a result, when a similar accident occurs, it is possible to recover from the accident without panic while confirming the suppression procedure. This is expected to have the effect of reducing equipment operation errors during work, and enabling recovery work to be carried out quickly and safely while suppressing the occurrence of new accidents.
Furthermore, since the system is easy to operate as described above, it can be easily handled by anyone without relying on an experienced operator unlike the conventional system. It is believed that this will make it easier to secure power-related workers amid fears of a shortage of human resources in the future.

Next, according to the bank reverse power flow suppression system of the second invention, the accident location is on the upstream side of the secondary bus, and the first line connecting the secondary bus and the distribution transformer is cut off, It is possible to instantly predict the occurrence of bank reverse power flow and reverse power flow in the secondary side distribution line when power is not supplied to the secondary bus from another power system, and to easily output the suppression procedure. becomes. As a result, when a similar accident occurs, it is possible to recover from the accident without panic while confirming the suppression procedure. This is thought to have the effect of suppressing equipment operation mistakes during work, and enabling recovery work to be carried out quickly and safely while suppressing the occurrence of new accidents.
Furthermore, since the system is easy to operate as described above, it can be easily handled by anyone without relying on an experienced operator unlike the conventional system. It is believed that this will make it easier to secure power-related workers amid fears of a shortage of human resources in the future.

Then, according to the bank reverse power flow suppression system of the third invention, the bank reverse power flow when the accident location is on the secondary bus and the second line connecting the tertiary bus and the distribution transformer is not interrupted. It is possible to instantly predict the occurrence of , and easily output the suppression procedure. As a result, when a similar accident occurs, it is possible to recover from the accident without panic while confirming the suppression procedure. It is thought that this has the effect of suppressing equipment operation mistakes during work, and that recovery work can be carried out quickly and safely while suppressing the occurrence of new accidents.
Furthermore, since the system is easy to operate as described above, it can be easily handled by anyone without relying on an experienced operator unlike the conventional system. It is believed that this will make it easier to secure power-related workers amid fears of a shortage of human resources in the future.

According to the bank reverse power flow suppression system of the fourth invention, the accident location is on the tertiary bus bar, the second line connecting the tertiary bus bar and the distribution transformer is cut off, and another line is connected to the tertiary bus bar. It is possible to instantaneously predict the occurrence of bank reverse power flow when power is not supplied from the power system, and to easily output the suppression procedure.

As a result, when a similar accident occurs, it is possible to recover from the accident without panic while confirming the suppression procedure. It is thought that this has the effect of suppressing equipment operation mistakes during work, and that recovery work can be carried out quickly and safely while suppressing the occurrence of new accidents. Furthermore, since the system is easy to operate as described above, it can be easily handled by anyone without relying on an experienced operator unlike the conventional system. It is believed that this will make it easier to secure power-related workers amid fears of a shortage of human resources in the future.

Further, according to the bank reverse power flow suppression method of the fifth invention, it is assumed that the accident location is upstream of the secondary bus and the first line connecting the secondary bus and the distribution transformer is not cut off. In response to the input, immediately shutting off the secondary distribution line is output as a suppression procedure. For this reason, when an accident occurs under the same conditions, it is possible to simply enter the location of the accident and the connection status of equipment on the power system without rushing to identify the source of the bank reverse power flow. A suppression procedure can be derived, and countermeasures against bank reverse power flow can be taken at an early stage.
In addition, although it is a simple method, it presents an accurate procedure for suppressing bank reverse power flow, so mistakes in equipment operation during work can be suppressed, and restoration work can be carried out quickly and safely while suppressing the occurrence of new accidents. It is considered that there is an effect that

Next, according to the bank reverse power flow suppression method of the sixth invention, the accident location is on the upstream side of the secondary bus, the first line connecting the secondary bus and the distribution transformer is cut off, and In response to an input indicating that power is not being supplied to the secondary bus from another power system, immediate shutdown of the secondary side distribution line is output as a suppression procedure.

For this reason, when an accident occurs under the same conditions, it is possible to simply enter the location of the accident and the connection status of equipment on the power system without rushing to identify the source of the bank reverse power flow. A suppression procedure can be derived, and countermeasures against bank reverse power flow can be taken at an early stage. In addition, although it is a simple method, it shows an accurate procedure for suppressing bank reverse power flow, which reduces equipment operation mistakes during work, and enables quick and safe recovery work while suppressing the occurrence of new accidents. It is thought that there is an effect that it can be done.

Furthermore, according to the bank reverse power flow suppression method of the seventh invention, when the accident location is on the secondary bus bar and the second line connecting the tertiary bus bar and the distribution transformer is not interrupted, On the other hand, it outputs that the tertiary side distribution line is cut off immediately as a suppression procedure. For this reason, when an accident occurs under the same conditions, it is possible to simply enter the location of the accident and the connection status of equipment on the power system without rushing to identify the source of the bank reverse power flow. A suppression procedure can be derived, and countermeasures against bank reverse power flow can be taken at an early stage.
In addition, although it is a simple method, it shows an accurate procedure for suppressing bank reverse power flow, which reduces equipment operation mistakes during work, and enables quick and safe recovery work while suppressing the occurrence of new accidents. It is thought that there is an effect that it can be done.

According to the bank reverse power flow suppression method of the eighth invention, an input indicating that the accident location is on the tertiary bus and that the first line connecting the secondary bus and the distribution transformer is not interrupted. On the other hand, immediately interrupting the secondary side distribution line is output as a suppression procedure. For this reason, when an accident occurs under the same conditions, it is possible to simply enter the location of the accident and the connection status of equipment on the power system without rushing to identify the source of the bank reverse power flow. A suppression procedure can be derived, and countermeasures against bank reverse power flow can be taken at an early stage.
In addition, although it is a simple method, it shows an accurate procedure for suppressing bank reverse power flow, which reduces equipment operation mistakes during work, and enables quick and safe recovery work while suppressing the occurrence of new accidents. It is thought that there is an effect that it can be done.

1 is a configuration diagram of a bank reverse power flow suppression system according to an embodiment of the present invention; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the example of an electric power system for demonstrating the bank reverse power flow suppression system which concerns on embodiment of this invention. It is a figure which shows the example of the 1st output display screen of the bank reverse power flow suppression system which concerns on embodiment of this invention. It is a figure which shows the example of the 2nd output display screen of the bank reverse power flow suppression system which concerns on embodiment of this invention. FIG. 9 is a diagram showing an example of a third output display screen of the bank reverse power flow suppression system according to the embodiment of the present invention; FIG. 10 is a diagram showing an example of a fourth output display screen of the bank reverse power flow suppression system according to the embodiment of the present invention; 4 is a flowchart showing a processing procedure for deriving a bank reverse power flow suppression procedure using the bank reverse power flow suppression system according to the embodiment of the present invention; 4 is a flowchart showing a processing procedure for deriving a procedure for suppressing bank reverse power flow using the bank reverse power flow suppression system according to the embodiment of the present invention; FIG. 4 is a diagram for explaining occurrence of bank reverse power flow;

Hereinafter, a bank reverse power flow suppression system and a bank reverse power flow suppression method using the same according to the present invention will be described with reference to FIGS. 1 to 8. FIG.
FIG. 1 shows the configuration of a bank reverse power flow suppression system according to an embodiment of the present invention. The bank reverse power flow suppression system 1 stores an input unit 2 for inputting predicted accident locations and equipment information about equipment on the target power system, and the predicted accident locations and equipment information input from the input unit 2. A procedure for suppressing bank reverse power flow by identifying the source of bank reverse power flow that is expected to occur by grasping the blackout section and line connection state in the power system while checking with the power system data stored in section 4. and a procedure output unit 5 for visually confirming the suppression procedure derived by the data processing unit 3 by displaying it on a display or outputting it to a printer. .

Next, the contents of the information to be input in the input unit 2 will be described with reference to the basic model diagram of the electric power system. FIG. 2 schematically shows a power system related to the bank reverse power flow suppression system shown in FIG. are configured to be supplied with power respectively. The arrow indicates the direction in which power is supplied from the power plant.

In the power system 6 shown in FIG. 2, current flowing along transmission lines 7 and 8 flows into banks 10 and 11 while being connected by primary bus 9 on the way. These inflowing currents are further divided into currents flowing in the first lines 7a, 8a and second lines 7b, 8b in the banks 10, 11, the currents in the first lines 7a, 8a being secondary currents of each bank. The current in the second lines 7b, 8b flows toward the tertiary bus 8h installed on the tertiary side. The current is finally supplied to consumers connected to the secondary and tertiary busbars.

Next, facilities installed on the power system 6 will be described. Disconnecting switches 7c, 7e, 8c, 8e, 9a and circuit breakers 7d, 8d, 9b are installed on the transmission lines 7, 8 and on the primary bus 9.
The above facilities are essential facilities in the electric power system, and in addition, a plurality of disconnectors and circuit breakers are installed on the downstream side of the banks 10 and 11 . Although the installation conditions vary depending on the power system, FIG. 2 shows all facilities that may be installed on the power system. Facilities that may be installed include circuit breakers (7f and 8f in order) installed between the banks 10, 11 and the secondary bus 7h, and between the banks 10, 11 and the tertiary bus 8h. It is the circuit breaker (7g, 8g in order) to be installed. Further, circuit breakers 12 and 13 are installed in order on the secondary bus 7h and the tertiary bus 8h so as to adjust the flow of currents flowing from the banks 10 and 11, respectively.

Secondary distributed power sources 14 and 15 are connected in order to the secondary bus 7h via secondary distribution lines 18 and 19, and tertiary distributed power sources 16 and 17 are connected in order to the tertiary bus 8h. They are connected via tertiary side distribution lines 20 and 21 . Both the secondary distribution lines 18 and 19 and the tertiary distribution lines 20 and 21 are provided with circuit breakers.
Here, one of the information required in the bank reverse power flow suppression system 1 is the connection state of facilities located downstream of the banks 10 and 11 . In addition, the distribution line connected to the secondary bus 7h and the tertiary bus 8h shall be processed within the bank reverse power flow suppression system 1 assuming that they are always connected.

On the other hand, most of the accidents on the power system occur at points P1 to P8 surrounded by dashed lines in the figure. Here, points P1, P2, P4 and P5 are upstream of the secondary bus 7h, points P3 and P6 are on the secondary bus 7h, and points P7 and P8 are on the tertiary bus 8h. Basically, the circuit breakers 7d and 9b are shut off when accidents occur at P1 to P3 and P7, and the circuit breakers 8b and 9b are shut off when accidents occur at P4 to P6 and P8.
These circuit breakers 7d, 8d, and 9b are cut off in order to prevent power from being supplied from the power plant to the location where the accident occurred, and to ensure safety during restoration work. However, if the circuit breakers are not properly operated, the power loads on the power system may become unbalanced, causing reverse bank power flow from the distributed generation.

An example of utilization of the bank reverse power flow suppression system when it is predicted that an accident will occur at P1 to P3 and P7 in such a power system 6 will be described with reference to FIGS. 3 to 6. FIG. In the case where P4 to P6 and P8 are the fault locations, the results are similar to those of P1 to P3 and P7 due to the symmetry of the line structure of the electric power system 6, so the description thereof will be omitted.

First, the case where it is predicted that an accident will occur at P1 will be described. FIG. 3 is a diagram showing an example of the first output display screen of the bank reverse power flow suppression system according to the embodiment of the present invention. Although common to all of FIGS. 3 to 6, the power system diagram in the figure is the same as that in FIG. The description is omitted. In addition, explanations are given in the figure for various displayed figures.

As shown in FIG. 3, when it is predicted that an accident will occur at P1 on the upstream side of the secondary bus 7h (corresponding to an accident on the transmission line), the circuit breaker 7d, 9b is basically cut off (marked as "basic cutoff point" in FIG. 3). Although the disconnector 7e is in the connected state, it may be in the disconnected state because the connected state of the disconnector 7e does not affect the generation of the bank reverse power flow. This is because, regardless of the connection state of the disconnecting switch 7e, the downstream side of the accident site becomes a blackout section (a section in which the power load is lower than usual) that can be said to be an essential condition for the bank reverse power flow to occur.

Here, if the circuit breaker 7f on the first line 7a is not interrupted, the current indicated by the arrow symbol flows from the secondary side distributed power supply 14 to the secondary bus 7h in the blackout state, and then the circuit breaker 7f. It becomes a bank reverse power flow that passes through and goes to the bank 10 side. It can be easily understood that in order to suppress such a bank reverse power flow, it is sufficient to cut off the secondary distribution line 18 between the secondary side distributed power source 14 and the secondary bus 7h, which is the starting point of the arrow. . If the secondary side distribution line 18 is marked with an easy-to-visually confirmable mark as shown in this figure, it becomes possible to intuitively understand the cut-off point.

Next, the case where it is predicted that an accident will occur at P2 will be described. FIG. 4 is a diagram showing an example of a second output display screen of the bank reverse power flow suppression system according to the embodiment of the present invention.
As shown in FIG. 4, when it is predicted that an accident will occur at P2 on the upstream side of the secondary bus 7h (bank failure or the like is the cause of the accident), the power plant The circuit breakers 7d and 9b are basically cut off so that the power from the source is not supplied to the accident location (indicated by symbols as "basic cutoff location" in FIG. 4). In addition, the circuit breakers 7f and 7g adjacent to the fault location are also normally shut off as basic shutoff locations. The disconnecting switch 7e may be in the connected state or in the disconnected state as described above.

Here, when the circuit breaker 7f on the first line 7a is interrupted and the secondary bus 7h is not supplied with power from another power system (meaning that the circuit breaker 12 is in the interrupted state). , the current indicated by the arrow symbol becomes a bank reverse power flow from the distributed power source 14 to the secondary bus 7h in the blackout state. It can be easily understood that such a reverse power flow can be suppressed by cutting off the secondary distribution line 18 between the secondary distributed power source 14, which is the starting point of the arrow, and the secondary bus 7h. If the secondary side distribution line 18 is marked with an easy-to-visually confirmable mark as shown in this figure, it becomes possible to more intuitively understand the cut-off point.

Next, the case where it is predicted that an accident will occur at P3 will be described. FIG. 5 is a diagram showing an example of a third output display screen of the bank reverse power flow suppression system according to the embodiment of the present invention.
As shown in FIG. 5, when it is predicted that an accident will occur at P3 on the secondary bus 7h, the circuit breakers 7d and 9b are basically cut off so that power from the power plant is not supplied to the accident location ( Indicated by a symbol as "basic cut-off point" in Fig. 5). In addition, circuit breakers 7f, 12, and 18 adjacent to the fault location are also normally shut off as basic shutoff locations. The disconnecting switch 7e may be in the connected state or in the disconnected state as described above.

Here, if the circuit breaker 7g on the second line 7b is not interrupted, the current indicated by the arrow symbol flows from the distributed power supply 16 to the tertiary bus 8h in the blackout state, and then passes through the circuit breaker 7g. As a result, the bank reverse power flow toward the bank 10 side. It can be easily understood that such a reverse power flow can be suppressed by cutting off the tertiary distribution line 20 between the tertiary distributed power source 16, which is the starting point of the arrow, and the tertiary bus 8h. If the tertiary side distribution line 20 is marked with an easy-to-visually confirmable mark as shown in this figure, it becomes possible to more intuitively understand the cut-off point.

Next, the case where it is predicted that an accident will occur at P7 will be described. FIG. 6 is a diagram showing an example of a fourth output display screen of the bank reverse power flow suppression system according to the embodiment of the present invention.
As shown in FIG. 6, when it is predicted that an accident will occur at P7 on the tertiary bus 8h, circuit breakers 7d and 9b are basically cut off so that power from the power plant is not supplied to the accident location ( Indicated by a symbol as "basic cut-off point" in Fig. 6). In addition, circuit breakers 7g, 13, and 20 adjacent to the accident location are also normally shut off as basic shutoff locations. The disconnecting switch 7e may be in the connected state or in the disconnected state as described above.

Here, if the circuit breaker 7f on the first line 7a is not interrupted, the current indicated by the arrow symbol flows from the secondary-side distributed power supply 14 to the secondary bus 7h in the blackout state, and then the circuit breaker 7f. It becomes a bank reverse power flow which goes through and goes to the bank 10 side. It can be easily understood that such a reverse power flow can be suppressed by cutting off the secondary distribution line 18 between the secondary distributed power source 14, which is the starting point of the arrow, and the secondary bus 7h. If the secondary side distribution line 18 is marked with an easy-to-visually confirmable mark as shown in this figure, it becomes possible to more intuitively understand the cut-off point.
As can be said for any of FIGS. 3 to 6, the display method is not particularly limited. For example, another design drawing may be used, and other useful information for work may be displayed. can be

As described above, the bank reverse power flow suppression system 1 can output the bank reverse power flow suppression procedure in a clear display format. Next, a method of deriving a procedure for suppressing bank reverse power flow, which is used by the data processing unit 3 of the bank reverse power flow suppression system 1 during processing, will be described.
FIG. 7 is a flow chart showing a processing procedure for deriving a bank reverse power flow suppression procedure using the bank reverse power flow suppression system according to the embodiment of the present invention.

In order to derive the bank reverse power flow control procedure, the user of the bank reverse power flow control system 1 first inputs whether or not the location where the accident is predicted to occur is upstream of the secondary bus, as shown in FIG. (Step S1). If it is determined in step S1 that the location is on the upstream side of the secondary bus, then input is made as to whether or not the first line is cut off (step S2). In this step S2, if the target first line is not cut off, a bank reverse power flow from the secondary side distributed power supply occurs, so that the secondary bus and the secondary side distributed power supply The bank reverse power flow suppression system 1 judges that the secondary side distribution line must be cut off (step S4), and outputs this as a suppression procedure.

On the other hand, if the first line is cut off in the previous step S2, then input whether power is being supplied to the secondary bus from another power system (step S3). In this step S3, if it is assumed that power is being supplied from another power system, the bank reverse power flow will not occur from the secondary side distributed power source, so it is not necessary to cut off the secondary side distribution line. The reverse power flow suppression system 1 determines (step S5) and outputs this as a suppression procedure. On the other hand, in the previous step S3, when power is not supplied from another power system, bank reverse power flow or reverse power flow occurs. The system 1 judges (step S4) and outputs this as a suppression procedure.

Further, in step S1, if it is assumed that the location where the accident is predicted to occur is not on the upstream side of the secondary bus, the processing is performed based on the flowchart shown in FIG. Here, FIG. 8 is a flow chart showing a processing procedure for deriving a bank reverse power flow suppression procedure using the bank reverse power flow suppression system according to the embodiment of the present invention. This is done when the predicted location is not on the upstream side of the secondary bus.
First, in step S6, whether or not the second line is cut off is input. The bank reverse power flow suppression system 1 determines that the tertiary side distribution line must be cut off (step S8), and outputs this as a suppression procedure.

On the other hand, if it is determined in step S6 that the second line is cut off, next input is whether or not power is being supplied to the tertiary bus from another power system (step S7). In this step S7, if power is being supplied from another power system, bank reverse power flow does not occur from the tertiary side distributed power source, so it is not necessary to cut off the tertiary side distribution line. The suppression system 1 determines (step S9) and outputs this as a suppression procedure.
On the other hand, in step S7, if power is not supplied from another power system, a reverse power flow occurs in the tertiary bus, so it is necessary to cut off the tertiary side distribution line. The system 1 judges (step S8) and outputs this as a suppression procedure.

As described above, in the bank reverse power flow suppression system and method of the present invention, it is possible to determine whether or not bank reverse power flow will occur simply by inputting the location where an accident is predicted to occur and facility information on the power system. It has the effect of being able to easily and quickly output the suppression procedure when it occurs. Due to this action, accident countermeasures can be perfected, and when an accident involving bank reverse power flow occurs, the worker can output the suppression procedure without panicking and perform the work accurately. It is also expected that recovery work can be performed quickly and safely while minimizing mistakes.

Moreover, since the operation itself is simple, anyone can easily output the bank reverse power flow suppression procedure without relying on an experienced operator as in the past. In addition, since the amount of data to be processed is small and it can be used with a tablet computer, etc., it is possible to work while checking the output contents at the site, and it is thought that the work can be done quickly and accurately.

The bank reverse power flow suppression system and the bank reverse power flow suppression method using the system of the present invention eliminate the possibility of bank reverse power flow occurring due to a ground fault, disconnection accident, or the like in an electric power system to which distributed power sources are connected. Useful in some cases.

DESCRIPTION OF SYMBOLS 1... Bank reverse power flow control system 2... Input part 3... Data processing part 4... Storage part 5... Procedure output part 6... Power system 7... Transmission line 7a... 1st line 7b... 2nd line 7c... Disconnector 7d Circuit breaker 7e Disconnector 7f, 7g Circuit breaker 7h Secondary bus 8 Transmission line 8a First line 8b Second line 8c Disconnector 8d Circuit breaker 8e Disconnector 8f, 8g Breaker 8h... Tertiary bus 9... Primary bus 9a... Disconnector 9b... Circuit breaker 10, 11... Bank 12, 13... Circuit breaker 14, 15... Secondary side distributed power supply 16, 17... Tertiary side distributed type Power supply 18, 19, 20, 21... Circuit breaker

Claims (4)

A secondary distributed power source is connected to the secondary bus of the distribution transformer via a secondary distribution line, and a tertiary distributed power source is connected to the tertiary bus of the distribution transformer via a tertiary distribution line. In a power system to which a power source is connected, if an accident occurs on the secondary bus, the tertiary side distribution line is cut off to prevent the reverse direction from the tertiary side distributed power source to the distribution transformer. A bank reverse power flow suppression system that prevents power flow from occurring,
an input unit for inputting information about an accident occurrence location and facilities existing on the power system;
a storage unit storing power system line data;
a data processing unit that determines whether or not to cut off the secondary distribution line based on the information input from the input unit and the power system line data;
The data processing unit determines to cut off the tertiary side distribution line when a second line connecting the tertiary bus and the distribution transformer is not cut off. Bank reverse power flow suppression system. A secondary distributed power source is connected to the secondary bus of the distribution transformer via a secondary distribution line, and a tertiary distributed power source is connected to the tertiary bus of the distribution transformer via a tertiary distribution line. In a power system to which a power source is connected, in the event of an accident on the tertiary bus, the secondary side distribution line is cut off to prevent the reverse direction from the secondary side distributed power source to the distribution transformer. A bank reverse power flow suppression system that prevents power flow from occurring,
an input unit for inputting information about an accident occurrence location and facilities existing on the power system;
a storage unit storing power system line data;
a data processing unit that determines whether or not to cut off the secondary distribution line based on the information input from the input unit and the power system line data;
When the second line connecting the tertiary bus and the distribution transformer is cut off and power is not supplied to the tertiary bus from another power system, the data processing unit A bank reverse power flow control system characterized by judging to cut off a secondary side distribution line. A secondary distributed power source is connected to the secondary bus of the distribution transformer via a secondary distribution line, and a tertiary distributed power source is connected to the tertiary bus of the distribution transformer via a tertiary distribution line. In a power system to which a power source is connected, if an accident occurs on the secondary bus, the tertiary side distribution line is cut off to prevent the reverse direction from the tertiary side distributed power source to the distribution transformer. A bank reverse power flow suppression method for preventing power flow from occurring, comprising:
A bank reverse power flow suppressing method, wherein the tertiary side distribution line is cut off when a second line connecting the tertiary bus and the distribution transformer is not cut off. A secondary distributed power source is connected to the secondary bus of the distribution transformer via a secondary distribution line, and a tertiary distributed power source is connected to the tertiary bus of the distribution transformer via a tertiary distribution line. In a power system to which a power source is connected, in the event of an accident on the tertiary bus, the secondary side distribution line is cut off to prevent the reverse direction from the secondary side distributed power source to the distribution transformer. A bank reverse power flow suppression method for preventing power flow from occurring, comprising:
When the second line connecting the tertiary bus and the distribution transformer is cut off and power is not supplied to the tertiary bus from another power system, the secondary side distribution line A bank reverse power flow suppression method characterized by blocking.

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