JPS6349458B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power transmission line protection relay device that prevents unnecessary reactions and improves reliability.

Conventionally, a variety of protective relay devices have been used to protect power systems, but a distance relay method at stage limit has mainly been used as a back-up protective relay device for power transmission lines. The second stage protection range of this distance relay is set to about 120 to 150% of the distance of the own section so that it can reliably detect the bus bar of the other terminal, and at the same time the distance of the protective relay of the adjacent section is set. ,
and coordination of time setting.

FIGS. 1 and 2 illustrate the distance and time coordination of conventional backup protection relays. In the figure,
A, B, C are electric stations, 1, 1A, 1B are power transmission lines,
2A and 2B are distance relays, 2X, 2Y, and 2Z are the first stage, second stage, and third stage of the distance relay 2A placed at electric station A, and 3A and 3B are the bridges and disconnectors, respectively. . In such a system, when an accident occurs at point _F1 , the first stage of distance relay 2A at electric station A causes one stage of breaker 3A to operate for an instant (usually without using a special time limit). ). In the event of an _F2 accident, it will be detected by the second stage of distance relay 2A at electric station A, and will be disconnected after the time limit set by the second stage. The _F3 accident is detected by the first stage of the distance relay 2B at the B electric station, and the shield breaker 3B is disconnected according to the operating time of that first stage. In the case of an F ₄ accident, the distance relay 2
B is detected by the second stage, and the shingle breaker 2B is shattered in two stages. At this time, the operation time of the first stage and the time limit of the second and third stages are set to be the same regardless of the distance of the power transmission line.

On the other hand, in the above, the presence of a short-distance power transmission line adjacent to a long-distance power transmission line or the presence of a three-terminal power transmission line becomes a factor that inhibits the coordination of such back-up protection relays. Hereinafter, with reference to FIGS. 3 and 4, it will be explained that unnecessary responses occur due to loss of coordination of the distance relays. Figure 3 shows the case of a short-separation transmission line adjacent to a long-distance transmission line, and Figure 4 shows 3
The case of a power transmission line adjacent to a terminal transmission line is shown respectively,
In FIGS. 3 and 4, the same parts as those shown in FIG. 1 are denoted by the same reference numerals.

First, in Fig. 3, if power transmission line 1A is sufficiently longer than line 1B, distance relay 2 of electric station A
The operating range of the second stage of A is 120 to 150 of its own interval.
%, the operating range of the second stage may overlap with the outside of the first stage of the distance relay 2B in the next section. At this time, if an accident occurs at a point where the overlapped parts exist, for example at point _F5 , the operation of the second stage of distance relays 2A and 2B will cause the respective 2
Tameshiya disconnector 3 where stages are set at the same time limit
Cut A and 3B almost simultaneously. However, in this case, the shear disconnection of the sheath breaker 3A is unnecessary, and this unnecessary sheath disconnection has a very large influence on the system. Therefore, as a countermeasure, it is possible to delay the time limit of the second stage of the distance relay 2A, but in the event of a bus accident at electric station C, delaying the second stage would be
This is unfavorable from the viewpoint of system stability.

Next, in FIG. 4, if the distance from the branch point of the transmission line 1A to the electric station D is longer than the distance from the branch point of the transmission line 1A to the electric station C, then the distance relay 2 of the electric station A
In setting the distance of the second stage of A, in order to detect a fault up to the busbar of the D electric station, depending on the distance of the transmission line 1B in the next section, the distance of the first stage of the distance relay 2B may be set to the outside of the first stage of the distance relay 2B. Distance relays 2A and 2B at
The operating ranges of the stages overlap. Therefore, in this case as well, the _F4 point accident will cause the disconnection switch 3A to become unnecessary or disconnected, as described above.

The present invention has been made to solve the above problems, and its purpose is to provide a power transmission line protection relay device that can prevent unnecessary reactions of the device and reliably protect power transmission lines.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 5 shows an example of the configuration of a distance relay device according to the present invention.
A and 1B are power transmission lines, 2A and 2B are distance relays for stairway limit, 3A, 3B, and 3C are bridges and disconnectors, 4 is a directional distance electric device for detecting faults in the external direction of the power transmission line, and 6 is a transmission device. It is. FIG. 6 shows an example of the characteristics of the external direction distance relay 4 used in the present invention shown in FIG. This is a distance element that operates in the event of an internal accident on the power transmission line 1B. In other words, if an accident occurs in the direction of electric station C of electric station B, this device detects this using the directional element 4A, and transfers this condition through a transmission device 6 such as a power line carrier to the opposite terminal of electric station B. In addition to delaying the two-step lock or time limit of the distance relay 2A at a certain electric station A, the operation of the distance element 4B causes the disconnector 3C at the electric station B to be disconnected at a two-step time limit. It is composed of

In addition, in FIG. 5, the dashed line portion 5 is the distance element 4.
It shows the tripping time of the shield breaker 3C due to B.

Next, in such a configuration, if an accident occurs at point _F5 shown in the figure, directional element 4A of directional distance relay 4
and distance element 4B operate, and at the same time, the direction element 4A delays the two-step locking or time limit of the distance relay 2A of the A power station, and at the same time, the distance element 4B delays the two-step lock or time limit of the distance relay 2A. or be cut off. In addition, in the case of an accident at point _F6 , the directional distance relay 4 of the B electric station operates, but the first stage of the distance relay 2B quickly disconnects the sheath breaker 3B. on the other hand
If an accident occurs at point F ₇ , the first stage of the distance relay 2B at the B electric station will be inoperative, the second stage will be activated, and at the same time, the directional element 4A of the directional distance relay 4 will be activated, and the distance element 4B will be inoperative. . Therefore, the direction element 4A
Due to the operation of the distance relay 2A, the two stages of the distance relay 2A of the A electric station operate, but because the locking or time limit is delayed, it is faster for the two stages of the distance relay 2B to disconnect the cable breaker 3B. Distance relay 2A at electric station A will not be cut off if it becomes unnecessary.

In this way, in the back-up protection relay device that protects power system transmission lines by the distance relay method at the time of stage limit, the direction distance elements 4A and 4B that detect only the internal fault in the minimum adjacent section, and the adjacent section The directional distance relay 4 includes a directional element 4A for detecting accidents in the direction, and the directional distance relay 4 includes the directional distance elements 4A and 4B.
The operation causes the breaker 3C in its own section to break with a time limit equivalent to the second stage, and the directional element 4A
By this operation, the operation of the distance relay 2A at the other terminal in the own section is locked or delayed by a time limit.

Therefore, by applying this device, even if the operating range of the two stages of the distance relay is extended on a short-distance transmission line or three-terminal transmission line adjacent to a long-distance transmission line, the original time limit of the relay can be maintained. It is possible to coordinate distance and time without changing time, and it is possible to prevent unnecessary responses of the power supply equipment and reliably protect power transmission lines.

Although the above embodiment is applied to a short-distance transmission line adjacent to a two-terminal long-distance transmission line shown in Figure 3, the same applies to a three-terminal power transmission line as shown in Figure 4. It can be applied to

In addition, the present invention can be modified and implemented in various ways without changing the gist thereof.

As described above, according to the present invention, it is possible to provide an extremely reliable power transmission line protection relay device that can protect a power transmission line system by preventing unnecessary reactions of the device.

[Brief explanation of the drawing]

1 to 4 are diagrams showing the outline and characteristics of a conventional distance relay device, FIG. 5 is a schematic configuration diagram showing an embodiment of the present invention, and FIG. 6 is a diagram showing the directional distance element in the present invention. It is a figure which shows the characteristic example of the relay used as a. 1, 1A, 1B... Transmission line, 2A, 2B... Distance relay, 3A, 3B, 3C... Line breaker, 4...
... Directional distance relay, 6... Transmission device.

Claims (1)

[Claims] In a protective relay device that protects power system transmission lines using the distance relay method at the first stage, there is a direction distance element that detects only internal accidents in the minimum adjacent section, and a direction distance element that detects accidents in the direction of the adjacent section. and a directional distance relay consisting of an element, the operation of the directional distance element interrupts the disconnection of the own section, and the operation of the directional element locks the operation of the distance relay of the other terminal of the own section. Or, a power transmission line protection relay device characterized in that it is configured to cause a time delay.