JPH04109821A - Fault section isolating system for distribution line employing intelligent slave station - Google Patents

Abstract

PURPOSE:To perform isolation of fault section and automatic reverse transmission to all sound sections on load side by a system wherein a remote control slave station for locating fault point opens a section switch instantaneously upon receiving information from ground fault sensors in adjoining sections and a normal open switching point slave station detects power interruption due to opening of the section switch to throw in a normal open switch instantaneously. CONSTITUTION:Upon occurrence of ground fault in a pole 7 connected with a sensor 2:22. a ground fault direction detecting relay 1-4 detects ground fault occurring on a distribution line 9. On the other hand, information is broadcasted from the ground fault direction detecting relay 1-4 to slave stations. The sensor 2-22 detects the ground fault and which is notified to #2 slave station 2-20 and #3 slave station 2-30. The #2 and #3 slave stations 2-20, 2-30 recognize occurrence of ground fault in #2 section and opens section switches 3-2, 3-3 immediately. A slave station 5 connected with a section switch 4 for communication throws in the section switch 4 immediately. Consequently, isolation is carried out through a method principally suitable to the purpose of system and a highly reliable logical system can be configured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for removing faulty sections and transmitting power to healthy sections in high-voltage distribution line ground fault accidents.

(Prior Art) FIG. 3 shows the configuration of a conventional distribution line protection system. In Figure 3, 31 is the main transformer of the substation;
2 is a circuit breaker (CB), 33 to 36 are section switches (SW), and 37 to 40 are delayed closing operation mechanisms (hereinafter abbreviated as DM) that have a certain delay time before generating the closing voltage of the switch. ).

Next, the operation of the distribution line protection system configured as shown in FIG. 3 will be explained. Each section switch 33° 34, 35.
36 are maintained in the on state by the applied voltage from the corresponding DM37 to DM40.

If a ground fault occurs in section #3, a protection relay (not shown) in the substation will detect the ground fault and operate the circuit breaker 32 to interrupt the circuit. At the same time, each section switch 33~
36 is DM37~DM40 due to no voltage on the distribution line.
It loses the input voltage and becomes OFF. The return circuit breaker 32 is automatically closed for a certain period of time, but each DM is set with a delay time (x time) until it generates a closing voltage.
There is a time difference of several tens of seconds from when the circuit breaker 32 is automatically turned on until the #3 section is recharged (until the circuit breaker is operated again by the R wire grounding in the #3 section and the circuit is cut off). Accompany. This time allows the operator to recognize that section #3 is an accident section.

After that, the circuit breaker 32 is closed again, but after the automatic closing of the circuit breaker 32 last time, #ID M37 and #2DM
No. 38 indicates that the closing function is not locked (Y-locked) because the circuit breaker 32 did not shut off again within a certain period of time (7 hours) after closing the corresponding section switches 33 and 34, but #
The 3DM 39 detects that the circuit breaker 32 has operated to disconnect again within a certain period of time (7 hours) after the sectional switch 35 is closed, and the closing function is locked (Y-lock), so the sectional switch 35 is not closed. As a result, power transmission only from the power source side from the accident section was resumed.

Thereafter, in order to transmit power from the accident section to the load side section, the operator closes the normally open switch 41 connected to other lines by remote control or manually. Additionally, in the accident section, patrol inspections will be carried out to discover the accident location and restore the area.

In the conventional system described above, the power was cut off at least twice in the healthy section, and the load side in the faulty section was manually restored based on the judgment of the operator, so it took more time to transmit power. In addition, it was necessary to investigate the cause of the accident at all utility poles within the sectional switch and between the utility poles. In order to solve these problems, an accident detection function using a ground fault sensor installed on each utility pole will notify the accident location via the accident location sensor fault point locating slave station - master station, Not only can this be determined for each utility pole, but also the control computer can make a comprehensive judgment based on the operation information of the substation protection relay and the sensor information, and determine the switch operation procedure to disconnect the fault section and reverse the load-side healthy section. Fault section isolation using a computer that can be created instantly, sends switch control commands to slave stations via the master station, and eliminates the fault section without causing the circuit to be interrupted by the circuit breaker. There is a system.

(Problem to be solved by the invention) However, in order to construct an accident section isolation system using a computer, it is necessary to know the connection route information and current status of the distribution line system, the power to be supplied to each section, and the information on each distribution line. A large-scale control computer that knows the supply capacity is required, and a high-speed communication network is required to quickly transmit information to substation information transmission equipment and local location stations. In addition, in order to create procedures, it is necessary to accurately understand the current status of the sectional switch (on/off), and in areas where switches are not 100% remotely controlled, it is difficult to create accurate procedures due to lack of information. may be difficult. There is also a limit to the number of control units per accident due to the communication time required for transmitting the ground switch control command between the computer, master station, and slave station.

The present invention solves these conventional problems, and aims to provide a reliable distribution line fault section isolation system based on a simple principle centered on the isolation slave station without constructing a large-scale system. This is the purpose.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a power distribution line accident section isolation system that has: ■ ground sensor; ■ orientation function/isolation function; and power outage monitoring function/accommodation function. A remote control slave station for fault point locating; ■A master station that has the function of not only polling monitoring and control but also reporting feeder ground fault information from the ground fault information transmission device to all slave stations; It consists of a ground fault information transmission device that transmits ground fault information for each feeder to the master station device under the conditions of the fault relay, and the remote control slave station for fault point location is classified based on the detection information of the ground fault sensor in the adjacent section. The switch is immediately opened, and the normally open/closed slave station detects the power outage caused by the opening.
By immediately turning on the normally open switch, it is possible to disconnect the faulty section and automatically reverse feed the healthy section on the load side.

(Function) Therefore, according to the present invention, it is possible to construct an accident section isolation system that performs almost the same function as a conventional computer-based system without using a control computer or a high-speed transmission line.

(Embodiment) FIG. 1 shows the configuration of an embodiment of the present invention. In Fig. 1, 1 is a substation, which includes a circuit breaker 1-1 that cuts off the power supplied to the distribution line, a zero-phase current transformer 1-2 that detects ground fault current, and a grounding substation. It includes a transformer 1-3 and a ground fault direction detection relay 1-4. Reference numeral 2 denotes a ground fault detection system for each pole, which is installed in correspondence with the sectional switch for each section, and includes a ground fault detection sensor for the utility pole in the corresponding section, a master station 11, and a corresponding sectional switch 3. It has slave stations that exchange information between them. Reference numeral 3 indicates a section switch which is provided corresponding to each pole ground fault detection system 2 and opens and closes the feeder, 4 is a communication section switch which communicates with other feeders, and 5 indicates a communication section switch 4. A slave station to be controlled, 6 an information transmission line (CL), 7 utility poles, 8 a grounding line corresponding to each utility pole 7, and 9 a power distribution line.

FIG. 2 shows a flowchart when a ground fault occurs in the embodiment of FIG. 1.

Next, the operation of the above embodiment will be explained with reference to FIGS. 1 and 2.

In a normal power distribution system, power is supplied from a bus bar (BUS) of a substation 1 to a power distribution line 9 through a circuit breaker 1-1. This distribution line 9 has section switches 3-1 (SWI), 3-
2 (SW2), 3-3 (SW3), and 3-4 (SW4) are installed in #1 section and #2 section.

It is divided into section #3 and section #4. In a healthy power transmission state, all the section switches 3-1 to 3-4 are turned on, and power is supplied to all sections of the power distribution line 9.

Moreover, the communication division switch 4 is open.

Telephone pole 7 to which sensor 2-22 of section #2 is now connected
When a ground fault occurs (Sl), the ground fault direction detection relay 1-4 of the substation 1 detects that a ground fault has occurred in the distribution line 9, and shuts off the circuit breaker 1-1. Start issuing commands.

On the other hand, information on the operation of the ground fault direction detection relay 1-4 is transmitted to the master station 1.
1 to all slave stations in the distribution line (S2.S
3). Further, the sensor 2-22 detects a ground fault and the #2 slave station 2-20. #3 Notify the slave station 2-30 (S4). #2 slave station 2-20. The #3 slave station 2-30 reliably recognizes that a ground fault has occurred within the #2 section by receiving the simultaneous notification of the operation of the ground fault direction detection relay 1-4 and the detection information from the sensor 2-22. Sectional switch 3-2 (SW2
), 3-3 (SW3) is immediately opened (S5). #3
This will result in a power outage in section #4, but the slave station 5 connected to the communication section switch (SWT) 4 will have no voltage on the fault distribution line side and the ground fault direction detection relay 1
Upon receiving the simultaneous notification of 4, the communication section switch 4 is immediately turned on (S6).

(Effects of the Invention) As is clear from the above-mentioned embodiments, the present invention has the advantage that the section switch in which the ground fault has occurred is disconnected, and the section where the power outage has occurred as a result is disconnected. Moreover, on one side, the charged switch connects itself and transmits power, and disconnection is performed in a method that is ideally suited to the purpose of the system, making it possible to construct a highly reliable system with no logical contradictions. . Furthermore, since a control computer and high-speed transmission line are not used, the system can be constructed at a lower cost than in the past, and installation space is not an issue.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the configuration of a distribution line fault section isolation system according to an embodiment of the present invention, Fig. 2 is an operation flowchart when a ground fault occurs in the embodiment of Fig. 1, and Fig. 3 is a system of a conventional power distribution protection method. FIG. 1... Substation, 1-1... Circuit breaker, 1
-2... Zero-phase current current transformer, ■-3... Grounding transformer, 1-4... Earth fault direction detection relay 2 (2
-1, 2-2, 2-3, 2-4)...Each pillar ground fault detection system, 2-1O...#1 slave station, 2-20...
・#2 slave station, 2-30...#3 slave station, 2-4
0...#4 slave station, 2-11. 2-12.2-1
3゜2-21.2-22. 2-23. 2-31. ．．
2-32.2-33. 2-41.2-42. 2-4
3... Ground fault detection sensor, 3 (3-1, 3-2, 3-
3,3-4)...District public switch, 4...Communication section switch, 5...Slave station T, 6...Information transmission path, 7
...Electric pole, 8...Grounding wire, 9...Distribution line,
11... Master station, 31... Main transformer, 32...
Circuit breaker, 33.34.35.36... Sectional switch, 37, 38.39.40... Delay closing operation mechanism,
41...Normally open switch.

Claims (1)

[Claims] When a ground fault occurs on a high-voltage distribution line, the control computer determines the fault section based on the logical product of the ground fault notification from the ground fault sensor installed on each utility pole and the substation ground fault relay information, and the fault occurs. In the accident section isolation system, the section where the accident occurred is separated by opening the division switch that sandwiches the section, and then reversing the load side section from the accident section by turning on the normally open (normally open) switch of the other distribution line. The slave station installed corresponding to the sectional switch directly opens the sectional switch based on the notification from the ground fault sensor and the AND condition of the substation ground fault relay information, which causes a power outage. A distribution line using an intelligent slave station, characterized in that for a load-side section where a normally open switch is connected, a slave station installed corresponding to a normally open switch detects an instantaneous power outage and directly closes the normally open switch. Accident section separation system.