JP2010207056A - Power interchange processing method of power distribution system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that any arithmetic operation is not possible so long as a the tree structure is not formed when constituents of a power distribution system are dealt with by a graph theory to form the tree structure and an optimum solution for power interchange is obtained for the entire tree when a power failure occurs. <P>SOLUTION: A power interchange calculation processing section of an operation processing device is equipped with a loop releasing means, the loop releasing means removes the side of a loop of a power interchange path formed by power feeding points and demanding points when a power failure occurs to form a power network to be recovered from the power failure in a tree structure. When a fault occurs, a weight adding means adds different weight scores to a demand point of a sound route and a demand point of a fault route, and a power interchange route is calculated based on the magnitude of the sum of the weight scores. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power interchange method for a distribution automation system, and more particularly to a power interchange processing method for a distribution system that enables multi-stage interchange.

  In a distribution automation system that is a computer system that manages a distribution system, when a power failure occurs in the distribution system, or when a power failure occurs within a limited range due to construction, etc., it is different from the normal power supply route. A function of searching for a power supply route and supplying power from the obtained route is provided.

Non-patent document 1 is known as a calculation method for performing power interchange.
In this method, the distribution system is handled by graph theory, and when the input graph is limited to “tree”, an optimal solution is efficiently obtained. For this purpose, the algorithm finds the optimal solution by using the special structure of the tree. In this method, there are three components that are necessary to handle the power system interchange calculation problem with graph theory: a supply point, a demand point, and a switch.

  The supply point is a source for supplying electric power, and the main point of the distribution line is the transmission point of the distribution substation. A demand point is a point using electric power, such as a building, a factory, and a general household. A plurality of switches are switches installed on the power system.

In order to handle these three elements in graph theory, supply points and demand points are treated as “points”, and switches are treated as “edges”. Furthermore, by representing the supply quantity at the supply point and the demand quantity at the demand point with numerical values, it is possible to handle the distribution system in a graph, and represents a configuration that considers all the switches of the distribution system. The graph includes a cycle.
Sasakura, Shu, and Nishiseki: “Algorithms for solving tree partitioning problems” Technical Report COMP2001-87. IEICE of Japan (2002) p. 33-40 The Institute of Electronics, Information and Communication Engineers

  In Non-Patent Document 1, an input graph is limited to a tree, and an optimal solution is obtained using its special structure. However, in the interchange calculation in an actual power network, a plurality of data from the same feeder (one supply point) are used. There is a case where power can be supplied to the load section of the location, in which case the power network is no longer a tree and cannot even be input to the alcoholism. Therefore, the theoretically supported algorithm could not be applied to the distribution interchange problem. On the other hand, even if the input graph is a tree, there is a problem that the optimum solution cannot be obtained within the time allowed in the application of the distribution interchange problem.

  An object of the present invention is to provide a power interchange processing method for a distribution system that solves the above problems.

Claim 1 of the present invention provides a power interchange process based on data in the event of a power outage stored in a storage device when a power outage occurs in a power distribution system by an arithmetic processing unit having a power interchange calculation processing unit and a monitoring control unit. Computation is performed, and the arithmetic processing unit constitutes a graph for the power distribution system by means of division processing using graph theory, and divides into subtrees to calculate power interchange.
The interchange calculation processing unit is provided with a loop canceling unit, and when the power failure occurs, the loop canceling unit removes the side of the loop of the power interchange path formed by the power supply point and the demand point, and the power network to be restored by the power failure It is characterized by that.

  According to a second aspect of the present invention, a weight adding unit is provided in the accommodation calculation processing unit, and when the accident occurs, different weight points are added to the demand point of the healthy route and the demand point of the accident route by the weight adding unit. This is characterized in that the power interchange route is calculated based on the sum of the two.

  A third aspect of the present invention is characterized in that, at the time of power accommodation calculation by the accommodation calculation processing unit, the demand points of healthy routes are gathered and the number of demand points is reduced, and then the power accommodation route is calculated.

  As described above, according to the present invention, even when the power network is no longer in a tree structure at the time of a power failure in the distribution system, it is possible to accurately calculate power interchange using the tree structure by creating a virtual tree. In addition, the calculation speed can be increased.

  FIG. 1 is a system configuration diagram showing an embodiment of the present invention. 1 is a power distribution system, 2 is an arithmetic processing unit comprising a computer, and has a RAM, a ROM storage unit, a monitoring control unit 3 and a flexible calculation processing unit 4. is doing. Reference numeral 5 denotes a storage device, which stores equipment data of the distribution system 1, constraint condition data for system operation such as system configuration, actual load value, and switch state. The monitoring control unit 3 monitors the system state of the distribution system 1, that is, the connection of the system, the load power amount, and the switching state of the switch, and stores these states in the storage device 5. In addition to the division processing means using the graph theory of Non-Patent Document 1, the accommodation calculation processing unit 4 includes a loop release means, a weight addition means, and the like.

  When a power failure occurs in the distribution system, the monitoring control unit 3 detects the occurrence of a power failure and instructs the accommodation calculation processing unit 4 to perform the accommodation calculation. Based on this command, the accommodation calculation processing unit 4 executes accommodation calculation using system data, constraint condition data, and the like at the time of occurrence of an accident stored in the storage device 5.

  In the distribution system of the electric power company, since the loop operation of the system is not performed, the power network in the steady state has a tree structure as shown in FIG. In the figure, ◯ indicates a demand point that is a load node connected to the branch, and □ indicates a power supply point such as a distribution substation. When an accident occurs at the supply point □ having this tree structure, the power failure section immediately after the accident has a tree structure as shown in FIG. However, when a power outage occurs, power is supplied from the distribution system supply point outside the power outage section in order to recover from the power outage, so the power network in the power outage section to be considered is not a tree as shown in FIG. Since it is no longer a tree, application to the algorithm of Non-Patent Document 1 becomes impossible.

  In addition, in an actual power system, there are usually interconnected switches (normally open switches) that are open and can be accommodated by considering the calculation of interchange using these switches when accumulating power. Since the range is widened, calculation considering a normally open switch is desired at the time of interchange calculation. However, when this normally open switch is used (closed), as shown in FIG. 5 (a), for example, the path of loop 1 and loop 2 exists and is not in a tree structure. For example, the supply point n is set at two locations. Even if the loop 1 is eliminated by distribution, the loop 2 remains as shown in FIG.

  Furthermore, as shown in FIG. 6 (a), if an accident occurs at point a of the power system, it can be divided into a sound feeder A and an accident feeder B. , The demand line of A ′ that belonged to the healthy feeder A group has a power failure due to the supply route of the thick line shown in FIG. The power interchange source feeder A is originally a healthy feeder, and even if some of the feeders are interchanged, it is not allowed to cause a power failure of the healthy feeder.

In the present invention, when the closed loop is formed by using the normally open switch, the side that forms the closed loop is deleted by the loop releasing means that is one of the functions of the interchange calculation processing unit 4. A tree structure.
That is, when a closed loop as shown in FIG. 7A is formed, the closed loop is eliminated by removing the side between the demand points A and A on the loop as shown in FIG. . The loop release means pays attention to the supply point u and uses the property that the loop is canceled by removing one side from the loop, and searches for the side to be released when controlling the normally open switch.

  In the search in this case, since the number of sides is 6 from the supply point u as shown in FIG. 7A, six combinations may be calculated. Due to the nature of the power distribution system, the supply amount is often a few hundred amperes, and especially when only the remote control switch is taken into account, the loop at the place where the loop is formed is reversed. In many cases, the number above is at most several tens. For this reason, since there are few calculation cases for canceling the loop to form a tree structure, the calculation speed can be increased.

In the above description, attention is paid only to the loop including the supply point, but there are cases where two loops are formed as shown in FIG. When such a situation is assumed, pay attention to all the loops in the constructed graph, and by removing one edge each from all the loops, all the loops will be eliminated and the normally open switch will be handled. Can do.
In the case of FIG. 8, as shown in FIG. 8B, all the two loops are eliminated by removing the side between the demand points A and C and the side between D and E, thereby forming a tree configuration. Therefore, it becomes possible to handle a normally open switch, and there are more candidate routes that can be accommodated, and a more optimal accommodation route can be searched.

  As described above, a feeder that was originally healthy is not allowed to cause a power failure even if it is a part of the feeder through power interchange. FIG. 9 shows an example of the countermeasure, in which points (weights) are added to the demand points in addition to the demand amount. This point addition is performed by the weight load means of the flexible calculation processing unit 4, and for example, a point such as 10,000 points is added to a demand point that was originally healthy when a power failure occurs. For example, a small point of 1 or less is assigned. After the points are added, the arithmetic processing unit 2 executes a route search for power accommodation using existing technology, calculates the point sum of the obtained solution, and sets the route that maximizes the point sum as the optimum solution. Of course, the number of added points may be reduced on the healthy side, contrary to the above.

  In FIG. 9, if the supply amount of the supply point u is 55, the route with the maximum satisfaction amount (= 55) is the A group, but the total point at this time is 2000.4. Group B will be out of power. When the search by the accommodation calculation processing unit 4 becomes the demand route C shown in FIG. 10, the number of points becomes 5000.1 and becomes the maximum, and the sufficiency at this time becomes 42. In other words, the interchange calculation processing unit 4 searches for a supply route that is equal to or less than the supply amount of the supply point u and maximizes the point, and makes an optimal solution, and allows power to be supplied to the accident feeder without causing a power failure of the sound feeder.

The interchange calculation processing unit 4 can allocate power to the accident feeder without causing a power failure of the sound feeder by assigning points by the weight addition means when a power failure occurs, but even in that case, further speeding up of the arithmetic processing Is required.
FIG. 11 is based on such a request, and it is assumed that a group of healthy feeders A and a group of accident feeders B as shown in FIG. The accommodation calculation processing unit 4 does not perform the computation on the power accommodation path for each demand point for the group of the healthy feeder A, and (b) the five demand points and edges of the group A as shown in FIG. Are calculated as the demand amount 32 by reducing the number of demand points / sides.
Therefore, according to this method, the number of computation paths to be searched is reduced and the number of calculations is reduced, so that the calculation speed can be increased.

1 is a system configuration diagram of power accommodation showing an embodiment of the present invention. Explanatory drawing of the electric power network in a steady state. Explanatory drawing of the electric power network at the time of a power failure occurrence. Explanatory drawing of the electric power network after a power failure occurs. It is explanatory drawing of electric power interchange, (a) is a 2 loop formation state figure, (b) is a 1 loop residual state figure. It is explanatory drawing of electric power interchange, (a) is an accident occurrence state figure, (b) is a route search state figure. It is explanatory drawing of this invention, (a) is an accident occurrence state figure, (b) is a route search state figure. It is explanatory drawing of this invention at the time of 2 loop generation | occurrence | production, (a) is an accident occurrence state figure, (b) is a route search diagram. Explanatory drawing when adding points. Explanatory drawing at the time of the point addition of this invention. In other explanatory drawing of this invention, (a) is a state figure at the time of accident occurrence, (b) is a route calculation state figure.

DESCRIPTION OF SYMBOLS 1 ... Power distribution system 2 ... Arithmetic processing device 3 ... Monitoring control part 4 ... Accommodation calculation processing part 5 ... Memory | storage device

Claims (3)

By an arithmetic processing unit having a power interchange calculation processing unit and a monitoring control unit,
A power interchange processing calculation is performed based on data at the time of a power outage stored in a storage device when a power outage occurs in the distribution system, and the arithmetic processing unit uses a division processing means using graph theory to distribute the power distribution system. In the case of constructing a graph with respect to
The interchange calculation processing unit is provided with a loop canceling unit, and when the power failure occurs, the loop canceling unit removes the side of the loop of the power interchange path formed by the power supply point and the demand point, and the power network to be restored by the power failure A power interchange processing method for a power distribution system. A weight adding unit is provided in the interchange calculation processing unit, and when the accident occurs, a different weight point is added to the demand point of the healthy route and the demand point of the accident route by the weight adding unit, and based on the magnitude of the sum of the weight points. The power interchange processing method for a distribution system according to claim 1, wherein a power interchange route is calculated. 3. The power interchange of the distribution system according to claim 1, wherein the power interchange route is calculated after collecting demand points of the healthy route and reducing the number of demand points during the power interchange calculation by the interchange calculation processing unit. Processing method.

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