JPS63310333A - Load interchange mode determining system for power distribution system - Google Patents

Abstract

PURPOSE:To raise processing efficiency by immediately forming an optimum combination out of combinations of many load zones and adjacent power distribution line systems. CONSTITUTION:More suitable assignment than normal one can be performed by sequentially selecting load zones to which highly probable one can be applied as compared with a simultaneous study of all zones to be interchanged in the process of the assignment. (The process is finished when power distribution line systems to be assigned to all load zones are determined as designated in a block 101). Accordingly, the assigned section is sequentially removed from the load zone to be interchanged and to be processed, and associated with the adjacent power distribution line systems. These load zones to be interchanged are clearly modeled by the process in a block 102. The adjacent power distribution line systems which can be supplied to the load zones are extracted in a block 103, and either one is selected based on the information in a block 104.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for determining a load accommodation mode in a power distribution system, and in particular to a method for determining the route through which power should be supplied to each load section of a power distribution line. The present invention relates to a suitable method for determining a load accommodation mode for a power distribution system.

[Conventional technology]

Traditionally, as a method for determining load accommodation in power distribution systems, the
Discussed in Publication No. 1-12455 "Distribution Line Transmission System". In the method described in this publication, the distribution line to be accommodated is first reversed from the system of the directly connected substation within a margin, and then the sections that cannot be accommodated by this reverse transfer are relieved and relieved. In order to equalize the reserve capacity of side substations,
Adjustments will be made by interconnecting substations so that the load on substations with large power interchange reserves will be large.

(Problems to be Solved by the Invention) This is an attempt to simplify the process of deciding how to make accommodations and to carry out actual switch operation as early as possible.

However, with this method, for somewhat complex systems, there may be sections with power outages that cannot be accommodated, and in order to reduce power outages, it is necessary to temporarily transfer sections where reverse transmission is performed from the system of another substation. There are some problems such as In addition, the time required for the entire load accommodation including switch operation is determined not only by the accommodation calculation, but also by the characteristics of the switch being operated.
For example, it depends on the availability of remote control, and in that sense, it is not preferable to immediately start with reverse transfer.

An object of the present invention is to achieve high speed and minimize the number of power outage sections and the total amount of power outage load for a group of load sections of distribution lines connected in various shapes. The object of the present invention is to provide a method for determining a load accommodation mode.

[Means for solving problems]

The above objective is achieved by the following method. That is,
Adjacent Wi line systems that can supply to each load section to be accommodated are extracted as follows, and based on this information, the distribution line systems that should be accommodated for each load section are assigned. In a distribution line system, there is a switch that can be used from the distribution line system to the load section of interest, and the remaining reserve capacity of the distribution line system is within the load section of interest, including the section load in the middle of the supply route. The condition is that it can be covered.

When assigning the distribution line system obtained in this way to each load section,
For example, it is possible to select the feeder with the lowest number, but it is more efficient to take the following measures. used for.

(1) When the load section in the middle of supplying to the load section of interest is the only one on the route, or due to the characteristics of the connection switch, the distribution line system is linked to the assignment of the adjacent distribution line system to the load section of interest. The fact that it is necessary to allocate to a section that is not on the supply route in addition to the load section means that it is necessary to allocate the supply from the same system as that of the section of interest.

(2) When the assumption that all eight target load sections can be accommodated from any of the adjacent distribution line systems (ultimately there will be no power outage) is likely to hold true, (i) It is assumed that all the load sections subject to 8 transmissions can be accommodated from one of the adjacent distribution line systems (ultimately there will be no power outage); The only distribution line system mentioned above will be assigned to the load section that can be accommodated.

In addition, (it) The remaining reserves of the connected power line system are large, and if even one of them is not used for accommodation, a power outage will occur. When there is only one flexible load section, try allocating the above-mentioned distribution line system to this load section.

Note that if a situation in which a power outage cannot be avoided occurs in subsequent processing, the assumption of application of this rule will be broken, and the allocation will not be considered inevitable.

(3) Among the load sections to be accommodated, those with large loads are prioritized for allocation.

(4) Preferentially allocate load sections that require fewer operating procedures for connection switches for supply.

[Effect]

In determining the load accommodation mode, it is difficult to find out which adjacent distribution line system should supply each load section and the optimal combination of load sections and distribution line systems. Therefore,
When a system becomes large-scale, the number of combinations becomes enormous, and if combinations are extracted haphazardly, a large amount of processing time is required.

However, it can be seen that the distribution line system that can supply each load section is limited due to the upper limit of its remaining reserve capacity, etc., as described above. If one is selected from among the limited candidates based on the above-mentioned rules, the allocation will naturally be made with a high degree of necessity, and a combination close to the optimum can be realized. As a result, high-speed processing can be performed by avoiding combinational calculations required for many cases, and the amount of power outage load can be minimized.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure is a flowchart showing the procedure for determining the accommodation mode based on the present invention.

Usually, a power distribution system is operated so as not to form a loop, that is, by connecting a group of interchangeable load sections in a tree shape.

From now on, only adjacent distribution f11 line systems can be assigned to the same load section.

By the way, it is better to sequentially select the load amount TJI (not limited to one) to which the most likely one of the above-mentioned rules can be applied than to perform the allocation process on all the concessioned sections at once. It is considered that a more appropriate allocation than usual is possible (the process ends when the distribution line system to be allocated to the full load section is determined, as shown in block 101),
This can be said to be appropriate as it follows the tendency for the above-mentioned loop prohibition restriction to become stronger as processing progresses.

Therefore, the allocated portions are sequentially removed from the accommodating load section to be processed, and the adjacent distribution W! , it will be incorporated into the line system side (at this time, the remaining reserve capacity of the distribution line system will be allocated only for the target section load)
. These load sections to be accommodated and the like are clearly modeled in the process of block 102.

In block 103, adjacent distribution line systems that can supply each load section are extracted, and based on this information, in block 104, one is selected.

A case in which the process shown in FIG. 1 is applied to the power distribution system shown in FIG. 2 will be described below.

In the system shown in Figure 2, the connection arrangement is through a circuit breaker to the bus bar! ! If a ground fault occurs in the load section 321 of the line system, all load sections connected to the circuit breaker 22 will experience a power outage. However, in the portion indicated by 300 surrounded by a broken line, there is a possibility that a power outage can be avoided by load accommodation from the distribution line system of the adjacent circuit breakers 21 and 23. In order to process this accommodation calculation, the partial system 300 is extracted as an accommodation target. In order to facilitate subsequent processing, as shown in Figure 3, covered overload sections are designated as nodes, and the vine switches that connect interchangeable load sections (nodes) are designated as branches and interchangeable load sections (nodes). A feeder is treated as a feeder, including the adjacent distribution line switch that can be connected to it. Unlike a branch, as shown by the arrow, a feeder has only one end as a node. (Values shown in parentheses) Note that even when the same feeder is connected to multiple nodes, the reserve capacity in parentheses is shown for the entire feeder. The object of flexibility is not limited to 300 in FIG. 2, but may be, for example, the entire system.

In Figure 2, the value shown in parentheses at the circuit breaker indicates the capacity of the circuit breaker, and the value in parentheses at the load section indicates the load amount in the section. The inside shows the load amount of the corresponding section, and the small circle on the left shoulder or right shoulder shows the node in the extracted accommodating part.As for the feeder, Fl, Reattach it to F2.

The modeling of the accommodated portion as described above is performed in block 102 of FIG. In the example of the system shown in FIG. 2, in order to simplify the explanation, it is assumed that the branch and feeder switches do not depend on the direction of operation (there is no difference).

Next, the load section to be accommodated shown in block 103 of FIG.
Path=shortest load path) is calculated. SLP is the minimum total load from the inlet node of the feeder to each node of interest (including the inlet node) within the capacity of each feeder, and if SLP exists at the node of interest, the amount of load from the designated feeder is Indicates that supply is possible (required condition), and therefore which feeder's SLP for a given node.
If there is no power supply, there will be no supply to the area and a power outage will have to occur (a sufficient condition for a power outage).

As shown in FIG. 4(1), in a state where all the feeders are unprocessed, feeder F1 can supply to all nodes, and feeder F2 can supply to all nodes except ■. Note that in the SLP, the supply route indicated by an arrow and the route difference load amount written near the node are clearly indicated. Based on this SLP, block 104 in FIG.
process and allocate feeders to some nodes. That is, on the assumption that there is no power outage, Fl is assigned to ■, and Fl is also assigned to ■ on its only route. If F2 cannot be used (as is the case with Fl), the power that can be supplied by the feeder will be insufficient with respect to the total amount of load to be accommodated.

Also, since the only entry node for F2 is ■, assuming that there is no power outage (assign F2 to Φ).

Remove the processed part from the target, correct the feeder capacity and direct supply inlet node, and select S in Fig. 4 (2).
Get LP. From now on, assuming that only F2 can be supplied to ■ and there will be no power outage, F2 will be assigned to ■. Similarly below,
In the end, the flexibility calculation results shown at the end of FIG. 4 are obtained.

Here, some supplementary information regarding the above-mentioned rules is given below.

An example of the only route for rule (1) is node (1) in FIG. 4 (1), as described above. Here, it is possible to allocate feeder F2 to ■, but in this case, it becomes impossible to supply Fl to ■, which has already been allocated, and a contradiction occurs.

Therefore, ■ will also necessarily be assigned to Fl.

On the other hand, in the example shown in FIG. 5 (1), node ■ can only be supplied from feeder F1, so even if Fl is assigned to ■ and then F2 is assigned to node ■ on the temporary route, there will be no difference. Since the route ■→■→■→■→■ exists, it can be detoured, and ■→■→■ is not the only route. Whether or not a temporary route is unique is determined, for example, if a node on the temporary route is later used or provisionally allocated due to allocation by another feeder, the duplicate node (see Figure 4 (1)
), we temporarily remove ■, and in Figure 5 (1), we temporarily remove ■),
This can be determined by checking whether or not there is an SLP to a node that has been previously allocated.

However, depending on the connection shape of the nodes, it can be determined whether there is only one route without calculating the SLP.

In the system illustrated in FIG. 5(2), even if Fl is assigned to ■, it is clear that there is no other branch in the temporary route from ■→■→■, and there is no room for a detour.

Next, FIG. 4(3) shows an example in which the same feeder is allocated to different nodes in conjunction with the allocation. The switch between nodes ■ and ■ is different from those of other branches, and its operating characteristics differ depending on its orientation. That is, when ■ is charged, it is automatically turned on after a certain time period. On the other hand, even if ■ is charged, ■ does not turn on automatically and requires human operation. In addition, ■It is necessary to set a cut in advance so that it does not turn on automatically after charging. In this way, assigning Fl to ■ means assigning Fl to ■ at the same time.

The layout of rule (4) that requires fewer operating procedures will be explained using the example shown in FIG. 5 (3). When nodes ■ and ■ connected by a switch with the above-mentioned characteristics can be supplied from either feeder Fl or F2, if Fl is assigned to ■ (and therefore also to ■), one operation is enough, but ■ Assigning F2 to 2
Requires multiple operations. Therefore, it is better to take advantage of Fl.

Another embodiment of the present invention will be described with reference to FIG.

Regarding the accommodation target shown in Fig. 6 (1), the feeder Fl
, F2 can be supplied to all nodes. Therefore, using the above-mentioned rule (3), try feeding the node (2) with the largest load amount from the feeder F1. Then, by a procedure similar to that described above, (a-1) and (b-
The result shown in 1) is obtained, and in this case, the power outage load cannot be made smaller than the sum of ■ and ■ (4).
When assigned, the results shown in (a-2) and (b-2) are obtained, and the amount of power outage can be reduced by (2)
This results in a solution closer to the optimum. It is also close to optimal in terms of the small number of power outage sections.

In this way, there are cases in which the power outage load cannot be minimized using only the above-mentioned measures, and an optimal solution may not always be found. Therefore, even if (a-1) ((b-1)) is obtained, other candidate feeders will be assigned for areas where the necessary assignments were not made (for example, the assignment to ■ above). (As a result, (a-
2) (A solution like (b-2) is found).

In this way, if the necessity of feeder allocation is managed by its application rules, it is convenient to check other combinations, and by using the branch and bound method, it is possible to systematically check other combinations. Even when applying the branch-and-bound method, if the rules of this invention are used and the assignments with high necessity are prioritized, a solution closer to the optimal one can be obtained.
Modifications to combinations can be made as quickly as possible.

Improving the solution once obtained can be achieved not only by trying a different allocation according to the processing procedure as described above, but also by replacing the solution (node supply feeder) as described below. This will be explained using FIG. 7.

Although the feeder F1 is connected to the node (2) experiencing a power outage in FIG. 6(2)(b-1), the capacity is insufficient by one. Therefore, the supply from Fl to ■ is stopped (FIG. 7 (1)) and is instead supplied to ■ (FIG. 7 (2) Fl is used up to the upper limit of its supply capacity, which reduces the amount of power outages).

Next, F2 can be supplied to ■, so it is assigned as such. As a result, the power outage occurs only at node (2) (FIG. 7 (3)).

Note that this post-processing can be applied not only to reducing power outages by replacing feeders, but also to improving operability by switching ON and OFF switches.

〔Effect of the invention〕

As described above, according to the present invention, the accommodating mode can be quickly and easily applied to a group of accommodating load sections of distribution lines connected in any shape.
Moreover, it can be obtained as a quasi-optimal solution with the smallest amount of power outage load. In other words, in the present invention, among the many possible combinations of load sections and adjacent distribution line systems, those that correspond to combinations that are considered to be optimal are processed by directly creating the combinations, rather than using the ratios of the combinations. Increases efficiency (for example, if the number of load sections is 10 and the number of adjacent distribution lines is 3, the total combination including power outages is 4 tons)
There are so many ways to do this. In contrast, in the present invention, there is no process that requires particularly time, including calculations for determining the distribution line system, which can be assigned at most 10 times. ).

In the above explanation of the present invention, it is assumed that the same load section is supplied from only one distribution line system (loop is not possible), but even if a loop is allowed, it may be supplied via a section that has been assigned to another system. With the addition of the condition, the above S
This can be handled by calculating L and P.

Furthermore, in SLP, it is possible to reflect not only the capacity of adjacent distribution lines, but also the allowable capacity of switches, etc. along the route, and the voltage drop in load sections.

Note that the scope of application of the present invention is not limited to the power distribution system described here, but is broadly related to systems operated in the form of a network.

[Brief explanation of the drawing]

Fig. 1 is a processing flow diagram showing an embodiment of the present invention, Fig. 2 is a power distribution system diagram for explaining the embodiment, and Fig. 3 is an extraction of the part particularly related to the flexibility calculation from Fig. 2. Figure 4 is a diagram showing the processing situation on a system diagram, Figure 5 is a system diagram for supplementary explanation of the measures proposed by the present invention, and Figures 6 and 7 are different diagrams of the present invention. It is a system diagram etc. for explaining the Example of this. 20... Substation busbar, 21-23... Circuit breaker, 31
~33... Grid switch, 101-104... Processing block diagram, 211-234... Division switch, 300.
...Systems of the group of load sections to be accommodated, 311-334...Loads to be accommodated 1st turn λ 8th 381 Takuto Kyou (+) Flme SLP F2's SLP No. S mouth V4+ No. Q Figure

Claims (1)

[Claims] 1. In a load accommodation mode determination method that determines which load section should be used to supply power to a group of load sections belonging to a distribution line system set for each circuit breaker connected to the busbar of a distribution substation, At least a load section of the group of load sections that would cause a power outage if supplied only from the circuit breaker of the distribution line system to which it belongs is taken as the accommodated load section to be accommodated, and this taken in accommodation object is used as a node for each accommodated section. of,
A switch that can connect interchangeable sections as a branch,
Furthermore, it can be expressed as a network by using the adjacent distribution line system via a switch at the node as a feeder that can supply power within the specified capacity based on the remaining supply reserve to its own system in the interchangeable section. Therefore, the decision on the accommodation mode is treated as a problem of feeder allocation to each node, and the minimum value of the total load of the nodes on the route leading to each node is the feeder that can be supplied to each node. If it is less than the capacity, it is determined that it is possible (if it exceeds it, it is impossible), and one of the feeders that can be supplied is assigned to the node, and on the other hand,
A method for determining a load accommodation mode for a power distribution system, characterized in that a node without a supplyable feeder is treated as a power outage.