JPS6057297B2 - Distribution line reclosing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a distribution line reclosing method in a power distribution system having branches, and more particularly to a distribution line reclosing method that avoids faulty sections and retransmits power to healthy sections on the power source side.

In power distribution systems, several sectional switches are installed, and by combining these sectional switches and re-closing relays, when an accident occurs in a certain section, power is supplied to the distribution line where the fault occurred to avoid a power outage in the entire section. The line will be separated into a healthy section on the power side and a section with a power outage, and power will be retransmitted to the healthy section on the power source side.

Note that the power outage section is divided into an accident section and a healthy section on the load side, and power is provided to the healthy section on the load side from other distribution lines. Conventional reclosing methods can be broadly divided into low-speed reclosing methods, high-speed reclosing methods, and high-speed/low-speed reclosing combination methods, but in all methods, the sectional switch itself has a When the timer times up, a closing operation is performed to transmit power to the next section, and if the distribution line after the switch becomes non-voltage within a certain period of time after the closing operation, the section switch is opened and locked.

For this reason, in distribution systems with branches, there are operational problems in uniquely detecting fault sections. This will be explained using the power distribution system shown in FIG. 1 as an example. To aid understanding, the timers for each section switch are all set to the same time. Figure 1 shows
On the distribution line side via the substation side bus 1 and Shinsei 2, section switches 3 to 12 are provided to separate the load sections A-J, and the distribution system is branched at load sections B and G. 13 shows a protection device that issues a trifle signal in the event of an accident on the distribution line side.

In such a power distribution system, it is assumed that the sectional switches 3 to 12 have the same function and that an accident occurs in the load section D. In this case, the operation of the section switch in the conventional reclosing method is as follows. When an accident occurs, the breaker 2 breaks down and the section switches 3 to 12 are opened after the breaker 2 is disconnected. Next, the section switch 3 is turned on after a certain period of time after the Shiya Shinsei 2 is turned on. Further, after a certain period of time, the section switch 4 is turned on, and then the section switches 5 and 9 are turned on at the same time. Thereafter, section switches 6, 10 and 12 are closed simultaneously. At the same time as this turning on, if the accident continues in the load section D, the Shinsei 2 will be cut off. At this time, the section switches 6, 10,
12 is turned on with voltage for a certain period of time and is locked open by pattern recognition of no voltage within a certain period of time. after that,
With the reinsertion of Shinsei, power is transmitted to load sections A, B, C, and G as healthy sections on the power source side. Furthermore, the accident section D and the load-side healthy sections E, F, H, I, and J are power outage sections. Therefore, even though the accident section is only section D, section D
, H, and J are determined to be accident sections, and the power outage sections are also correctly sections D, E, and F, but in addition to those sections, sections H, I
, J is the power outage section. Therefore, at a certain time,
It is necessary to set the time limit for each section switch so that one section switch is closed. However, the system configuration of power distribution systems frequently changes, and updating the time limit settings of each section switch each time is a major operational problem, partly because the system is spread out.

The present invention performs closing control of a plurality of sectional switches at branch points of a distribution line individually for each route, and after completion of closing control of a sectional switch along a certain route, close control of a plurality of sectional switches at branch points along other routes is performed. The purpose of this study is to provide a distribution line reclosing method that enables accurate determination of fault sections.

The present invention introduces a computer that controls a sectional switch,
The connection relationship of the power distribution system is stored in the computer, and when the circuit is reclosed after an accident, the power supply side sequentially issues closing commands to the switches, and when this closing control reaches a branching point, first one section is switched on and off. After completion of closing control for a route in which a switch is selected and closed, and subsequent switches in the route of the closed switch are closed in sequence, the system returns to the branch point and performs closing control for other routes.

Such closing control is applied sequentially to each route at each branch point, and if the switch that belongs to the fault section is closed and the switch is opened without voltage, the switch is reclosed and the same procedure as above is performed. Since the switch belonging to the accident section is opened and locked in this control, it is possible to reclose the circuit to correctly determine the accident section. A specific example of the reclosing method according to the present invention will be explained using the power distribution system shown in FIG. 1. After closing, section switches 3 and 4 are closed in sequence.

After the switch 4 is closed, the load section B is a branch point, so the switch 5 that constitutes one of the routes is closed. The control procedure is to close switches 6, 7, and 8 after closing switch 5, but if the fault in load section D continues when switch 6 is closed, then At the same time, the switch 6 is opened and locked. Thereafter, section 2 is re-closed and switches 3 and 4 are re-closed in sequence, and at the branch point of load section B, switch 5 is closed. Thereafter, since the switch 6 is found to be locked open, the operator returns to the branch point and closes the switch 9 constituting the other route. After the switch 9 is closed, the load section G is a branch point, so one of the switches 10 is closed, and then the switch 11 is closed to complete the control of that route, and then the load section G is closed. The switch 12 constituting the other path is turned on to complete the re-closing control. As a result, the circuit is reclosed avoiding only the accident section D, leaving only the power outage sections D, E, and F. FIG. 2 shows a flowchart of the computer in the above-mentioned reclosing method of the present invention.

In addition, in order for the computer to recognize the configuration of the distribution system, the distribution line is expressed as a tree system, and in this case, the line breakers 2 and sectional switches 3 to 12 become branches, and the load sections are connected to nodes. Become. FIG. 3 shows a tree system corresponding to FIG. To explain the reclosing control according to the flowchart in Fig. 2, in step S1 it is determined whether or not the breaker of the distribution system to be controlled is closed, and after the breaker is closed, the reclosing control path is changed. Set node number N (step S2
).

The set node N and subsequent nodes are sequentially searched (step S3). In the sequential search of nodes, if the node has a leaf node (LeafNO) that does not have a SON
de) or not (step S4). Here, when there is a branch going from node P to node Q, node Q is called the sun of node P, and in FIG. 3, the sun of node A is node B, and the sun of node B is node C and node G. become. If it is not a leaf node, it is determined whether it is a branch node (step S5).

Here, a branch node means a node having two or more sons, and in FIG. 3, node B and node G are branch nodes. If it is a branch node as determined in step S5, the branch node number is stored in the stack memory (step S6). After going through steps S5 and S6, a division switch closing command for a branch located between the processing target node and the subsequent node is issued (step S7). It is determined whether the section switch targeted by this closing command has operated (step S8), and if the section switch has operated, it is determined whether the load section has become voltage-free by closing the switch. (step S9), and if the reclosure is successful, the process returns to step S3 and searches for the next node N+1 after node N. If re-closing fails due to the closing of the section switch belonging to the accident section node in step S8, the section switch memorizes that it is locked open (step SIO) and erases the contents of the stack memory (step Sll); The process returns to step S1 and waits for the disconnector to be turned on again. When the section switch which was locked open in the routine of steps S3 to S9 as described above is turned on by re-turning the breaker, the switch is not closed and the process proceeds from step S8 to step Sl2, where the open lock is turned on. It is detected that this is the case, and the process proceeds to step Sl3.

In step Sl3, in the case of a leaf node or an open lock in the determination of step S4, it is determined whether the branch node number remains in the stack memory, and if the branch node number is stored, the number is read out ( Step Sl
4) Return to step S3 as the node N, and continue the section switch closing control after the node N.

In addition, when the above-mentioned computer-based re-closing control also involves the closing control of the shingle breaker, a shingle breaker closing processing step is provided before step S1.

As described above, the reclosing method according to the present invention provides reclosing control that accurately determines the fault section, and has the advantage of being able to cope with changes in the system configuration by updating information on connections in the power distribution system.

[Brief explanation of the drawing]

Fig. 1 is a system diagram illustrating a power distribution system, Fig. 2 is a flowchart for explaining distribution line reclosing control according to the method of the present invention, and Fig. 3 shows nodes and branches corresponding to the system diagram in Fig. 1. It is a tree system diagram. 1... Substation side busbar, 2... Switching and disconnection, 3-12...
Sectional switch, 13...protective device, A-J...load section.

Claims (1)

[Claims] 1. When an accident occurs in a distribution system with branches, the above-mentioned method is used to select and reclose a group of sectional switches installed in the distribution system in order to avoid the accident section and retransmit power to a healthy section on the power source side. The sectional switches are sequentially closed along a route consisting of a group of sectional switches and their distribution lines, and at branch points in the distribution line, the sectional switches are sequentially closed along one route, and this route is controlled. A distribution line re-closing method characterized in that after completion of the above-mentioned branching point, the distribution line re-closing method returns to the branch point and controls closing of the section switches along other routes.