JPH01246732A - Throw-in resistor device for circuit breaker - 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 [Field of Industrial Application] The present invention relates to a gas circuit breaker, and particularly to a device for opening and closing a movable resistance contact in a gas circuit breaker with a resistance contact.

[Conventional technology]

Generally, in ultra-high voltage circuit breakers, high overvoltage is generated during the closing and breaking operations of the circuit breaker, so in order to suppress this, a resistor is connected in parallel with the circuit breaker.

4 and 5 show this, in which a series circuit of a resistive contact 2 and a resistor 3 is connected in parallel with the main contact 1. The resistance contacts are configured so that, under all system conditions, they open first during the breaking operation, as shown in Figure 4, and close before the main contact 1, as shown in Figure 5, during the closing operation. has been done.

A buffer type gas circuit breaker with this type of closing resistance device,
It is known that a movable side resistance contact of a resistance contact is formed in a movable portion of the interrupting part. However, the resistance contact on the movable side is firmly fixed to the movable side of the cut-off part, and there are no sufficient measures in place to facilitate insulation coordination between the main contact of the cut-off part and the resistance contact. It had not been done.

FIG. 6 shows a conventional general example.

A support insulator 5 fixed at a suitable position is provided in a closed container 4 filled with arc-extinguishing gas. A support conductor 7 is fixed to the support insulator 5 via a metal fitting 6, and further fixed to the support conductor 7, a fixed contact 8 and an electric field relaxation shield 9 surrounding the fixed contact 8 are provided. .

A movable contact 10 facing the fixed contact 8 is connected to the cylinder 1
1 and supported by a fixed piston 13. An insulating nozzle 12 surrounding the movable contact 10 is fixed to the cylinder 11 with a holding fitting 14.

The cylinder 11 and the piston 13 constitute a compression device, and the gas is compressed in connection with the opening/closing operation between the two contacts, and the insulated nozzle 12 sprays the gas to the arc between the contacts. The portion connected to the movable contact 10 constitutes a blocking portion.

A closing resistor device is provided electrically in parallel with the above-described interrupting section. The closing resistance device will be explained below. A support arm 15 fixed to the presser metal fitting 14 or the wall of the cylinder 11 extends in the radial direction of the interrupting portion, and has a movable resistance contact 16 attached to its free end. As shown,
The movable resistance contact 16 and the fixed resistance contact 30 constitute an abutting contact.

A metal fitting 7a is fixed to the support conductor 7, and an insulating arm 20 is coupled to this metal fitting 7a. This insulating arm 20 supports approximately the middle of the resistor 21, and the resistor 21 has a plurality of donut-shaped resistance elements 23 arranged in an insulating cylinder 22 and an insulating rod 24 passing through it.

The left end of the resistor 21 is connected to the support conductor 7 by a metal fitting 7b,
electrically and mechanically fixed.

An end fitting 26 is fixed to the right end of the insulating rod 24.
A spring 27 is disposed between the resistance element 6 and the end plate 28, and this spring applies contact pressure between each resistance element 23. A cylindrical body 29 is provided fixed to the end plate 28, and this cylindrical body 2
A fixed resistance contact 30 is provided which slides within 9. The fixed resistance contact 30 has a spring 31 provided between it and the end fitting 26.
is always biased to the right. Although the electrical connection is not shown in detail, the fixed resistance contact 30 is connected to the resistance element 2.
3 to the support conductor 7.

When both resistance contacts 16, 30 are in contact, a voltage corresponding to the impedance of the resistor 23 is applied between the fixed resistance contact 30 and the shields 9, 32, etc.

Therefore, a predetermined facing distance is required.

Here, the operation of this conventional interrupting unit and resistance contact will be briefly explained.

When the movable part of the interrupting part such as the cylinder 11 is driven to the left from the state shown in FIG. 6, the movable resistance contact 16 comes into contact with the fixed resistance contact 30 due to the difference in the facing distance, and the resistor 21 is inserted into the circuit.

Next, the movable contact 10 contacts the fixed contact 8, and both ends of the resistor 21 are short-circuited.

The fixed resistance contact 30 compresses the spring 31 and forms a dashpot chamber between it and the abutting portion of the cylinder.

On the other hand, the circuit is opened by driving the movable part of the blocking part to the right.

Due to the reaction force of the dashpot chamber, the fixed resistance contact 30 is
In order to move slowly to the right at the opening operation speed, first,
Resistance contacts 16 and 30 open and then contacts 8 and 1
0 is opened. The fixed resistance contact 30 then returns to the state shown. FIG. 7 is a schematic diagram showing only the resistance contact portion extracted. Even if a resistor device is configured to close in advance of the main contact or to close in advance, its effectiveness will be limited even under actual system voltage conditions unless insulation coordination between each electrode is achieved. Since this cannot be achieved, detailed electric field analysis is performed to determine its shape and operation.

However, the reality is that as the voltage per - point increases, insulation coordination becomes more difficult. While satisfying the inter-electrode dielectric strength during breaking operation, a preliminary discharge reliably occurs on the resistance contact side during closing operation, and even in the fully open state.
The conventional type has reached its limit in terms of satisfying the conditions for interelectrode insulation performance.

[Problem to be solved by the invention]

In the above-mentioned prior art, the fixed side resistance contact portion is configured to protrude at the time of closing, and to perform a delayed operation at the beginning of the breaking operation. This is also a means of insulation coordination for closing and breaking operations, but since such consideration was taken into consideration for the movable resistance contact, the adjustment range when trying to coordinate insulation for higher voltages is was small.

The object of the present invention is to provide an excellent resistance contact that has a higher electric field than the main contact side during the closing operation, which always causes a preliminary discharge on the resistance contact side, and that has sufficient dielectric strength during the breaking operation or in the fully open state. Our goal is to provide circuit breakers with

[Means to solve the problem]

The above object can be achieved by making the movable resistance contact also move within a certain limited area.

[Effect]

During the closing operation, the discharge starting voltage on the resistance contact side is lower than that on the breaking part side, that is.

The movable resistance contact is made to protrude and stroke toward the fixed resistance contact so that the electric field strength on the resistance contact side is higher than that on the blocking part side.

On the other hand, during the breaking operation, the movable resistance contact is retracted into the shield of the resistance contact and stroked to alleviate the electric field so that it can withstand the transient recovery voltage that appears between the poles at the time of breaking. By doing so, the input operation,
Both the breaking operation and the insulation coordination between the breaking part and the resistance contact can be performed very easily.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

Figure 1 shows the start point of the closing operation. 630 is a fixed resistance contact, and there is a shaft 35 passing through the plate of the arm 15 extending from the movable side, and a movable resistance with an electrode 36 attached to the end thereof. A contact point 37 is provided, and a shaft stop plate 38 is attached to the opposite end thereof.

The shaft 35 is configured to slide through a hole in the arm plate 15, and the leftward movement of the shaft 35 is caused by the arm plate 15 and the shaft stopper plate 38, and the rightward movement is caused by the stopper plate 3.
This is done using a stop plate 39 with holes pulled out from 8 and 15. In the final stroke of disconnection, the stop plate 38 is pushed to the left by the push rod 40, and the front surface of the electrode 36 protrudes from the left end of the shield 19, causing the electrode to slide to the left under high electric field conditions. Make sure to make the investment.

Also, the shaft 35 of the movable resistance contact contacts the fixed resistance contact and is pushed further to the left. The resistance contact 36 and the shaft stop plate 38 are pushed to the right side relative to the arm 15, the stop plate 39, or the shield 19, and the stop plates 38 and 39
stops and moves to the left as a whole until it reaches the wipe distance of the fixed resistance contact 30, completing the closing operation. Second
The figure shows the resistive contact in the fully closed condition.

FIG. 3 shows the interruption operation in progress.

The movable resistance contact operates in the breaking direction as shown in FIG. 3 while remaining in the state it was in when the closing operation was completed. That is,
The front surface of the electrode 36 of the movable resistance contact has moved toward the inside of the shield 19. In this state, each part is adjusted so that the discharge starting voltage on the resistance contact side is equal to or higher than the interpolation insulation recovery characteristic of the main interrupting part. Insulation coordination is achieved by relaxing the electric field.

At the final part of the cut-off stroke, the stop plate 38 comes into contact with the push rod 40, and when the cut-off part moves further to the right, the electrode shaft 35. The electrode 36 moves to the left and returns to the shape shown in FIG. 1, completing the interrupting operation.

According to this embodiment, it is possible to more easily achieve insulation coordination that provides a higher electric field strength than the cut-off part side in the closing direction operation and a withstand voltage that exceeds the insulation recovery characteristics of the cut-off part side in the cut-off direction operation. Therefore, it is possible to provide a buffer type gas circuit breaker with closing resistance that has a simple structure and high reliability.

〔Effect of the invention〕

According to the present invention, when performing the closing operation, the electric field on the resistive contact side is lowered by applying a higher electric field to the resistive contact side compared to the breaking section side, and when performing the interrupting side operation, the electric field on the resistive contact side is lowered. Insulation coordination can be easily controlled so as to sufficiently exceed the interpole transient recovery voltage during interruption.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a closing resistance contact in a state in which the closing is completed according to an embodiment of the present invention, FIG. Figures 4 and 5 are wiring diagrams showing the configuration of a circuit breaker with closing resistor, Figure 6 is a cross-sectional view of a conventional buffer type gas circuit breaker with closing resistor, and Figure 7 shows only the conventional closing resistor contact. FIG. 15... Arm plate, 19... Shield, 30... Fixed resistance contact, 31, 41.43... Spring, 35... Shaft, 36... Movable side resistance contact electrode, 38...・Shaft stop plate, 39... Stop plate, 40... Push rod, 44・
...Electron collection.

Claims (1)

[Claims] 1. A movable contact in a closed container filled with arc-extinguishing gas,
That is, a cut-off part having a movable cut-off part and a fixed contact;
A closing resistance device is provided electrically in parallel with the cut-off part and includes a resistor and a resistance contact, wherein the cut-off part is provided with a support arm plate extending outside thereof, and the movable side of the resistance contact is provided in the cut-off part. A closing resistance device for a circuit breaker, characterized in that the resistance contact is configured to be able to move by a predetermined distance in the axial direction of the interrupting section of the arm plate during operation of the interrupting section. 2. In claim 1, the surface of the movable resistive contact protrudes from the surface facing the fixed side of the shield provided near the movable resistive contact during the closing operation, and During operation, the circuit breaker closing resistance device retracts and strokes the movable resistance contact toward the inside of the shield.