JPS5857227A - Disconnecting switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] The present invention relates to a disconnector, particularly for insulating 8P6 gas! This invention relates to a disconnector formed from a fixed electrode, a movable electrode, a resistor, etc. for use in a gas-sealed substation as a medium.

By opening and closing the power circuit by means of a disconnector.

Charge current rushes into busbars, equipment, cables, etc. and is cut off. In this case, although it varies depending on the circuit conditions, it is known that a surge voltage nearly three times the peak value of the maximum normal ground voltage is generated. There is a possibility that the insulation will be adversely affected, and in order to improve insulation performance and reliability, it is important to reduce this surge voltage as much as possible. As a countermeasure to this problem, it has been proposed to open and close the disconnector via a resistor, and an example of this is shown in FIGS. 1 and 2. A main contact 2a consisting of a fixed electrode 2 and a movable electrode 3 is constructed in a grounded tank 1, and is connected to other equipment via a current collector 4, a conductor 5, etc., respectively. A resistor 6 is placed on the fixed electrode 2 side as shown in FIG.

It is arranged concentrically around the fixed electrode 2, and a firing electrode 7 is attached to its tip. Note that sF6 gas, which has excellent arc extinguishing and insulation performance, is sealed in the tank 1.

In the disconnector configured in this way, when the circuit is closed, the movable electrode 3 is electrically connected to the fixed electrode 2 as shown by the broken line in the figure.

When released, it moves to the right as shown by the arrow in the figure. At this time, an arc is generated at the tips of the fixed electrode 2 and the movable electrode 3 in the initial stage, but when the movable electrode 3 is separated to a certain extent, it is attached to the tip of the resistor 6 as shown by the solid line in the figure. The arc 8 moves between the arcing electrode 7 and the movable electrode 3, a circuit is formed via the resistor 6, and the cutoff state is then completed. Note that when the circuit is closed, the process is reversed, and after closing via the resistor 6, the circuit is closed.

By doing this, it is possible to significantly suppress switching surges, but in order to obtain the required performance, the resistor 6 must have a withstand voltage that is at least twice the peak value of the normal ground voltage. . UHV scheduled to start operation in the future (11
00kV class), a resistor 6 with a length of several hundred to several thousand is required, but the resistor 6 currently in general use is molded from resin or clay mixed with carbon. , is a fired resistance element, and even if the length of this resistance element is increased, the withstand voltage does not increase proportionally. For this reason, as the voltage class increases, the required length of the resistor element increases rapidly, so the structure of the disconnector must be made larger, and countermeasures to this problem are becoming an issue for gas-insulated substations, which are currently being downsized. was.

The present invention has been made in view of the above points.

The purpose is to provide a disconnector that can be made smaller.

That is, in the present invention, the resistor is formed of a resistor unit in which a plurality of resistor elements are connected in series in the axial direction by connecting fittings, and the resistor unit is arranged approximately concentrically around a fixed electrode. It is characterized by the fact that it has been

As mentioned above, the resistive element is made by molding and firing resin or clay mixed with carbon, and we investigated how such a resistive element changes depending on its length. The results of this study are shown in Figure 3. In this figure, the length of the resistance element is plotted on the horizontal axis, and the resistance value 1t is plotted on the vertical axis, and the variation characteristics depending on the length of the resistance element are shown. Even if a balance is created and a voltage is applied, the voltage is not distributed uniformly in the longitudinal direction and tends to concentrate in a certain part. This is because, as shown in the same figure, the resistance value 1 (,) at both ends of the resistance element becomes high, and the voltage sharing is concentrated in this part, which becomes a weak point in terms of insulation performance.

This tendency becomes larger as the length of the resistance element becomes longer.

In other words, when the length Lt of the resistance element is approximately 1000 mm, the increase Δ⇠ in the resistance value at both ends is large, as shown by the solid line in the figure, and therefore the maximum rate of change in the resistance value R (
ΔR/R) was also as large as 30%. On the other hand, the length l,
When S is about 3ooTran, the increase ΔR in the resistance value R at both ends is small, as shown by the dotted line in the figure.
Therefore, the maximum rate of change in the resistance value R (∆/I()) was reduced to less than 10%.For these reasons, it is better to form a resistor by using multiple short resistance elements of several FHmm. However, the insulation performance of the resistor is improved and the potential distribution is better than when the resistor is formed from one long resistor element.

It has been confirmed that it is possible to reduce the size of the resistor by about 20% at most. Therefore, in the present invention, the resistor is formed of a resistor unit in which a plurality of resistor elements are connected in series in the axial direction by connecting fittings, and the resistor unit is arranged approximately concentrically around the fixed electrode. I did it like that. By doing so, it is possible to obtain a disconnector that can be made smaller.

Examples will be described below. One embodiment is shown in FIGS. 4 and 5. Note that parts that are the same as those in the conventional model are given the same reference numerals, and therefore their explanations will be omitted.

In this embodiment, the resistor 6a is formed of a resistor unit in which a plurality of resistor elements 9, 10.11 are connected in series through connecting fittings 13.14 in the axial direction, and the resistor unit is surrounded by the fixed electrode 2. They are arranged almost concentrically. That is, the resistor 6a is formed of a resistor unit in which resistive elements 9 and 10°11 each having a unit length of several hundred U or less are connected together by a connecting fitting 13.14, and one end thereof is connected to a bolt 16 via a fixed voltage. It is attached to the top.

A plurality of these resistor units are arranged in parallel around the fixed electrode 2 as shown in FIG.

By doing this, the insulation performance of the resistor 6a is improved and the potential distribution is improved, so the length of the resistor 6a can be shortened, and the movable distance (stroke length) of the OJ moving electrode 3 (1) is reduced.
This makes it possible to reduce the size of the operating mechanism section, making it possible to obtain a disconnector that can be made smaller.

In addition, when the resistance elements 9 and 10.11 are connected in series, a connecting fitting 13.14 is used to connect between the resistance elements 9 and 10.11.
Therefore, if the minimum unit length of the resistive element 9.times.10.11 is made too short, the proportion occupied by the connection fittings 13.14, etc. will increase, which is not preferable, since the overall length will become long. The minimum unit length of the resistive elements 9 and 10° 11 is preferably selected to be about several hundred.

FIG. 6 shows another embodiment of the present invention. 1. Connecting fittings 14 for connecting resistive elements 10 are mechanically connected to each other by reinforcing members 17 made of insulators. . The connecting fittings 13 (see Fig. 4) and the connecting fittings located at the same position in the longitudinal direction are connected and supported by the reinforcing member 17, and the connecting fittings 14 and the connecting fittings located at the same position are also connected and supported separately.
do. By doing this, it is possible to prevent a decrease in mechanical strength of the resistor unit, which is a concern because the resistor 6a has a split structure, and even in a relatively long structure such as a UHV resistor. The effect of having sufficient mechanical strength is obtained, and reliability is improved.

In this example, the connecting fittings (connecting parts) are located at the same position in the axial direction.
Although the reinforcing members are used to connect the connecting portions to each other, it is not necessary to connect the connecting portions at the same position in the axial direction, and it is also possible to connect the connecting portions at different positions in the axial direction.
Further, the axial connection portion may be connected mechanically to at least one other connection portion by a reinforcing member.

Furthermore, it is also possible to make the reinforcing member a metal conductor instead of an insulator, and in such a case, the resistance elements 9, 10.1
Even if there is a slight difference in the resistance values of the resistive elements 9, 10 .
Since the voltage applied to the resistor 11 can be equalized, the potential distribution of the resistor can be improved.

As described above, in the present invention, the resistor is formed by a resistor unit in which a plurality of resistor elements are connected in series using connecting fittings, so the potential distribution of the resistor is improved and the resistor can be downsized. It became like this.

A disconnector that can be made smaller can be obtained.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional disconnector, and Figure 2 is A of Figure 1.
3 is a characteristic diagram showing the relationship between the length of the resistance element and the resistance value, and FIG. 4 is a longitudinal sectional view of the main part of the disconnector of an embodiment of the disconnector of the present invention, Figure 5 is B-B of Figure 4.
6 is a cross-sectional view of another embodiment of the disconnector of the present invention. DESCRIPTION OF SYMBOLS 1...Tank, 2...Fixed electrode, 3...Movable electrode, 6a...Resistor, 9,10.11...Resistance element,
12゜(1 other person)

Claims (1)

[Claims] 1. A grounded tank, and a fixed electrode, a movable electrode, and a resistor, which are provided in the tank and form a main contact when the circuit is opened and closed, a current-carrying part, and a movable electrode when the circuit is closed. In the disconnector, the resistor is energized and then the main contact is energized, and when the circuit is opened, the main contact is opened and then the resistor is opened. A disconnector is formed of a resistor unit in which resistive elements are connected in series through connecting fittings, and the resistor unit is arranged approximately concentrically around the fixed electrode. . 2.Equipped with a grounded tank, and a fixed electrode, a movable electrode, and a resistor that are provided in the tank and form the main contact and current-carrying part when opening and closing the circuit, and when the circuit is closed, the resistor is energized. In the disconnector, the main contact is energized, and when the circuit is opened, the main contact is opened and then the resistor is opened. The resistor unit is arranged substantially concentrically around the fixed electrode, and the axial connection portion of the resistor element is connected to at least one other resistor unit. A disconnector characterized in that it is mechanically coupled by a connecting part and a reinforcing member. 3. Claim 2, wherein the reinforcing member is an insulator.
Disconnector as described in section.