JPH0348728B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to real-time simulation of power systems, and is particularly necessary for calculating the range of power outages or determining system separation for monitoring the operating status of power systems. This paper relates to a system connection determination method.

[Conventional technology]

Figure 1 is a system diagram showing the power system, Figure 2 is the diagram showing the power system.
Figure 3 is a block diagram showing the table arrangement, and Figure 4 is a flowchart showing the operation of the conventional system connection determination method. , 1st
In the figure, 1 and 5 are busbars, 3 is a transformer, and 6
and 9 are disconnectors; 7 and 8 are disconnectors; 2 and 4 are connection lines between the disconnector 6 and the disconnector 7; and between the disconnector 9 and the disconnector 8.

In FIG. 2, a to e are nodes corresponding to the parts (connection lines, etc.) labeled 1 to 5 in FIG. 1, respectively, and f to i are nodes 6 to 9 in FIG.
These are the branches that correspond to the parts marked with (switches such as disconnectors and breakers), and the nodes and branches are expressed in a graph.

In FIG. 3, numeral 10 is a table of branch number size, and stores the from node number of the branch. 11 is a table of branch number size, and the to (destination) of the branch
Stores the side node number. 12 is a table of branch number size, and ON or OFF of the branch
Store state. However, the current system status is set as the initial value. 13 is a table of the size of the number of nodes, which indicates whether or not it is connected to an arbitrary starting point node, that is, ON or OFF, and indicates the range connected to the arbitrarily selected starting point node at the end of the determination. (node group).

Next, the operation will be explained. First, in the conventional system connection determination method, the system connection shown in FIG. 1 is represented graphically as shown in FIG. 2, and then the system connection is determined according to the flowchart shown in FIG.

First, in step ST1, an arbitrary node is selected as the starting point (here, a is taken as the starting point). Next, in step ST2, the convergence flag is turned on. Next, in step ST3, it is checked whether all branches (four branches in this example) have been focused on. Next, in step ST4, check whether the branch (table 12) is on or off, and if it is off, return to step ST3,
Find out about the next branch. If the branch is on, proceed to step ST5. At step ST5
In order to check whether the from side node (the node stored in the table 10) is on or off, the determination is made from the contents stored in the table 13 corresponding to that node. If it is off, proceed to step ST6; if on, proceed to step ST7.

In step ST6, in order to check whether the to side node (the node stored in the table 11) is on or off, a determination is made from the contents stored in the table 13 corresponding to that node. If it is off, return to step ST3 and check the next branch. If it is on, proceed to step ST8. Step ST8 turns on table 13 of the from side node, and step ST10
Proceed to. On the other hand, in step ST7, in order to check whether the to side node (the node stored in the table 11) is on or off, a determination is made from the contents stored in the table 13 corresponding to that node. If it is on, proceed to step ST11; if it is off, proceed to step ST9, and turn on the table 13 of the to side node.

In step ST10, the convergence flag is turned on, and in step ST11, table 12 of the branch in question is turned off, and the steps are repeated to repeat as many times as the number of branches.
Returning to ST3, when this number is reached, it is checked in step ST12 whether the convergence flag is on or off. If it is off, the process returns to step ST2, and if it is on, the one-way processing ends.

By performing the above operation, the table 13 shows whether or not it is connected to any starting point node, that is, ON or OFF, and the range (node group)
is shown.

Since the conventional grid connection determination method is configured as described above, it is important to note that even small parts such as connection lines 2 and 4 must be considered nodes, and that series connections are always connected in the power system as shown in lines 6 to 9. Since each switch must be treated as a branch, the number of nodes and branches in the graph to be determined becomes enormous, and therefore, the determination process takes time and requires a large storage capacity. It was hot.

The present invention has been made to solve the above-mentioned problems, and includes connection lines 2 to 4 and switches 6 to 4.
The purpose of this invention is to obtain a system connection determination method that can significantly reduce the number of nodes and branches in a graph by collectively representing 9 as a single branch.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 5 is a graphical representation of the system connection shown in FIG. 1 based on a system connection determination method according to an embodiment of the present invention. . j represents connecting lines 2 to 4 and switches 6 to 9 such as disconnectors and disconnectors as a single branch.

Next, a method of expressing a plurality of branches in FIG. 1 as a single branch as shown in FIG. 5 will be explained.

In other words, representation in a single branch is
This expresses whether or not bus bar 1 and bus bar 5 are electrically connected.

Here, it is determined whether or not the bus bar 1 and the bus bar 5 are electrically connected only when all of the switches 6 to 9 are in the closed state. to decide. Needless to say, the basis for this judgment is that if even one of the switches 6 to 9 is open, there is no electrical connection. Also, if a disconnection occurs in any of connection wires 2 to 4,
This is based on the fact that any of the switches 6 to 9 is automatically opened to protect the system.

Therefore, when all switches 6 to 9 are closed, branch j is closed (ON), and if any one of switches 6 to 9 is open, branch j is open (OFF). A graphical representation as shown in Figure 5 is possible.

Incidentally, after the graph is expressed as shown in FIG. 5 as described above, the system connection is determined according to the flowchart of FIG. 4 in the same manner as in the conventional system.

In addition, as described above, in the present invention, multiple switches, etc. are aggregated and expressed as a single branch, so the number of nodes and branches used for discrimination processing can be significantly reduced, reducing the time for discrimination processing. In addition, the storage capacity of the memory (tables 10, 11, 12, 13) used for the discrimination process can be reduced. For example, when comparing the conventional example and the embodiment of the present invention, the number of branches: 4 (conventional) → 1
(Invention of the present application), Number of nodes: 5 (conventional) → 2 (Invention of the present application), Number of memories in the table of node number size:
1. Number of memory for tables with branch number size:
3, the memory capacity of the present invention is about 30% compared to the conventional one [Number of nodes (invention) x number of node memories + number of branches (invention) x number of branch memories / number of nodes (conventional) ×
Number of node memories + number of branches (conventional) x number of branch memories = 2 x 1 + 1 x 3/5 x 1 + 4 x 3 = 5/17].

Although the above embodiment describes the case of grid connection in which the transformer 3 is connected between the busbars, the calculation method is not limited to this embodiment, and the same calculation method can be applied to power transmission lines, etc. It has the same effect as the example.

〔Effect of the invention〕

As described above, according to the present invention, when determining whether or not a branch having a plurality of switches is electrically connected, only when all of the plurality of switches are in the closed state. Since the branch is determined to be electrically connected, it is possible to aggregate parts that are always electrically connected such as transformers and switches, and express them as a single branch. The number of nodes and branches in the graph can be significantly reduced, the time required for discrimination processing can be shortened, and the storage capacity can also be reduced.

[Brief explanation of drawings]

Figure 1 is a system diagram showing the power system, Figure 2 is the diagram showing the power system.
Figure 3 is a block diagram showing the arrangement of tables; Figure 4 is a flowchart showing the operation of the conventional system connection determination method; Figure 5 1 is a graph representing the system connection shown in FIG. 1 based on a system connection determination method according to an embodiment of the present invention. 1, 5... bus bar, 3... transformer, 2, 4... connection line, 6, 9... disconnector, 7, 8... line breaker,
a~e...node, f~i...branch, j...
A single branch according to the invention. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. In a system connection determination method for determining whether or not arbitrary branches having multiple switches connected to the power system are electrically connected, all of the multiple switches included in the branch are in a closed state. A system connection determination method characterized in that it is determined that the branch is electrically connected only when the branch is connected.