JPH01307122A - Disconnecting switch - Google Patents

Abstract

PURPOSE:To miniaturize the apparatus, by projecting a movable electrode side end of an insulator between a contact cover and a fixed electrode side shield toward the movable electrode side more than the ends of a contact and the contact cover. CONSTITUTION:An insulator 3 is provided between a contact cover 30 and a fixed electrode side shield 31 consisting of a resistor. This insulator 33 is so constructed that the movable electrode side end 33a thereof projects towards a movable electrode 9 side more than the movable electrode side ends of a fixed electrode side contact 10 and the contact cover 30. As there is provided the insulator 33 between the contact cover 30 and the fixed electrode side shield 31, it is not required to provide a clearance between them, and a clearance l2' between the contact cover 30 and the fixed electrode side shield 31 can be made small. Thus, the apparatus can be miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a disconnector in a gas-insulated switchgear.

(Prior art) Disconnectors are used to disconnect equipment from the power supply during equipment inspection and repair, to change circuit connections, and to open and close electrical circuits. There are various types including those for voltage.

FIG. 3 shows the configuration of a conventionally used disconnector. That is, an insulating gas 2 such as SF6 gas is placed inside the metal container 1.
A conductor 4 connected to the fixed electrode terminal of the disconnector and a conductor 5 connected to the movable electrode terminal of the disconnector are supported and fixed to the metal container 1 by insulating spacers 3, respectively.

Further, a fixed electrode 6 and a fixed electrode contact 10 are arranged on the conductor 4 connected to the fixed electrode terminal, and a resistor 8 is arranged so as to roughly surround the fixed electrode contact 10. A metal shield 7 on the fixed electrode side is disposed therebetween.

On the other hand, a movable electrode side contactor 11 is connected to the conductor 5 connected to the movable electrode side terminal, and a movable electrode 9 is disposed inside the conductor 5 and is configured to be driven by an insulating rod 13. There is. Furthermore, a movable electrode metal shield 12 is disposed outside the movable electrode contact 11 so as to surround the movable electrode contact 11 .

Note that the insulating rod 13 is connected to an operating mechanism (not shown),
This operating mechanism causes the disconnector to open 4 and close.

A disconnector configured in this manner is generally required to switch the charging current on a short line.

Here, if the distributed capacitance and divided inductance of lines, transformers, etc. are approximately expressed as lumped capacitance and lumped inductance, respectively, and the line charging current switching/cutting circuit is expressed as an approximate equivalent circuit, for example, ,
It will look like Figure 4.

In the figure, 14 is the power supply voltage, 15 is the short circuit impedance, and 16
is the capacitance of the power supply side equipment, 17 is the inductance of the power supply side line, 18 is the capacitance of the load side line, 1
9 is the inductance of the load side line, and 20 is a disconnector.

In the disconnector shown in FIG. 3, the insulation recovery characteristics between the tip of the movable electrode 9 and the tip of the metal shield 7 on the fixed electrode side are as shown in FIG.

When a circuit as shown in FIG. 4 is cut off using a disconnector having such characteristics, a voltage waveform as shown in FIG. 6 is obtained. That is, in FIG. 6, a solid line 21 represents the voltage waveform at 819 points in FIG. 4, and a broken line 22 represents the voltage waveform on the power supply side.

The difference between the solid line 21 and the broken line 22 is the voltage between the poles of the disconnector.

To explain this relationship, for example, at point A, the movable electrode 9 and the fixed electrode side contactor 10 are opened, and then the movable electrode 9
When the tip comes out from inside the metal shield 7 on the fixed electrode side, the current is cut off at point B, and the power supply voltage at this time remains in the capacitance 18 on the load side, and the voltage between electrodes increases as the power supply voltage changes. . When the interelectrode voltage exceeds the insulation recovery voltage, it will fire again at the 0 point. However, since the current is small, it is quickly interrupted and the power supply voltage at this time remains in the capacitance 18 on the load side. In this way, restriking is repeated, and as the insulation recovery voltage rises, the voltage between the poles at the time of restriking also increases, but if the insulation recovery voltage exceeds the voltage between poles, the repeated restriking stops and the interruption is completed. . Re-ignition points in Figure 6, C, D, H, F
, G, and H correspond to the interpolar distances of C, D, E, F, G, and H shown in FIG. The restriking occurs between the tip of the metal shield 7 on the fixed electrode side and the tip of the movable electrode 9, and a restriking arc 23 as shown in FIG. 7 is formed.

When the electrode opening is completed in this way, the movable electrode 9 is housed inside the movable electrode side metal shield 12, and the electrode gap between the fixed electrode side metal shield 7 and the movable electrode side metal shield 12 is Must withstand voltage. Both of these shields also have the function of making the electric field between the electrodes nearly equal and increasing the withstand voltage between the electrodes.

Now, in the disconnector shown in Fig. 3, the fixed electrode 6
In a disconnector in which the resistor 8 inserted between the metal shield 7 on the fixed electrode side and the metal conductor is a metal conductor, the gap between the electrodes,
That is, when re-ignition occurs between the movable electrode 9 and the metal shield 7 on the fixed electrode side, high frequency vibration occurs in the circuit with capacitance 16.18 and inductance 17.19 shown in FIG. As shown in the figure, high frequency overvoltage 24
occurs. This high frequency overvoltage 24 becomes larger as the inter-electrode voltage when the disconnector is re-ignited becomes larger.

Moreover, this high frequency overvoltage 24 may threaten the insulation of the disconnector itself or other adjacent equipment. Therefore, in order to reduce the overvoltage at the time of restriking, as shown in Figure 3,
A resistor 8 is provided, and the current due to restriking at the time of opening is
Conductor 4 - Fixed electrode 6 - Resistor 8 - Fixed electrode metal shield 7 - Movable electrode 9 - Movable electrode contact 11 - Conductor 5. Trying to keep overvoltage to a minimum.

As a disconnector such as this, for example, Japanese Patent Publication No. 53-380 is used as a disconnector that allows current to flow during restriking to the resistor through the metal shield on the fixed electrode side and suppresses overvoltage due to loss in the resistor.
There is one disclosed in Japanese Patent Publication No. 31 or Japanese Patent Publication No. 60-42570.

In addition, in the disconnector shown in FIGS. 3 and 7, when suppressing the high frequency overvoltage that occurs when the circuit is re-ignited, a voltage is applied to the resistor 8, but since the resistor 8 can withstand this voltage, In this case, the resistor 8 must be changed. Furthermore, since the voltage of this resistor 8 is also applied to the gap indicated by It, 0-z in FIG. 7, the length of this portion must also be made long.

Therefore, the length Ll from the fixed electrode 6 to the tip of the metal shield 7 on the fixed electrode side and the length L2 from the center of the disconnector to the outer periphery of the metal shield 7 on the fixed electrode side shown in FIG.
There was a problem that the disconnector could not be shortened and the entire disconnector became large.

Therefore, in order to improve this point,
A disconnector as shown in Publication No. 32 has been proposed. That is, as shown in FIG. 9, a fixed electrode 6 and a movable electrode 9 are disposed facing each other inside the metal container 1, and the fixed electrode 6 has a fixed electrode side contact 10 at its center. Further, a fixed electrode side shield 25 made of a resistor is provided around it.

The fixed electrode side shield 25 is formed into a cylindrical shape with an arcuate section at its tip, and a metal electrode 26 is roughly arranged at the tip. Furthermore, a movable electrode-side metal shield 12 is arranged around the movable electrode 9.

In the disconnector configured in this way, when the disconnector is in an open state, that is, the movable electrode 9 is connected to the movable electrode side metal shield 1.
2, the movable electrode side metal shield 1 of the fixed electrode side shield 25 made of a resistor is
By the cross-sectional arc part formed in the part facing 2,
The two shields 25 and 12 are coupled so that the electric field between them can be made uniform and the withstand voltage between them can be increased.

Note that in the disconnector shown in FIG. 9, the opening operation is performed as described below. That is, when the movable electrode 9 is driven rightward in the figure when opening from the closed state, the metal electrode 26 formed at the tip of the fixed electrode side shield consisting of the movable electrode 9 and the resistor A discharge occurs between the two, and a discharge arc No. 27h is formed. At this time, the current flows from the movable electrode 9 to the fixed electrode 6 via the fixed electrode side shield 25 made of a resistor.

Furthermore, when the movable electrode 9 is driven and its tip comes out from inside the fixed electrode side shield 25 made of a resistor, as shown in FIG. The arc is re-ignited between the fixed electrode side shield 25 and a re-ignition arc 28 is formed. At this time, the restriking current flows from the movable electrode 9 to the fixed electrode 6 via the fixed electrode side shield 25 made of a resistor.

In this way, the current or restriking current flows through the resistor during the process of opening, so overvoltage is suppressed due to loss in the resistor.

Further, in FIG. 10, the voltage applied to the fixed electrode side shield 25 made of a resistor at the time of restriking is shared by the voltage distribution 3 from the region where restriking occurs to the end. That is,
Since the curved portion of the fixed electrode side shield 25 made of a resistor facing the movable electrode side shield 12 can also share the voltage, the fixed electrode side shield 25 made of a resistor
It is possible to shorten the axial length by 4.

In general, since the metal shield 7 on the fixed electrode side shown in FIG. 3 is not required, the length Ll shown in FIG. 3 can be shortened, and the disconnector can be made smaller.

(Problems to be Solved by the Invention) However, the disconnectors shown in FIGS. 9 and 10 have the following problems.

That is, in FIG. 10, when restriking occurs between the movable electrode and the fixed electrode side shield 25 made of a resistor, the voltage applied to the fixed electrode side shield 25 made of a resistor is Contactor 10 and fixed electrode side shield 2
5, so in order to withstand this voltage, the length of the wire 2 between the two must be made tighter, resulting in an increase in the size of the disconnector.

The present invention was proposed in order to eliminate the above-mentioned drawbacks, and its purpose is to shorten the distance between the fixed electrode side contact and the fixed electrode side shield consisting of a resistor, thereby reducing the size of the device. The objective is to provide a disconnector that makes this possible.

[Structure of the Invention] (Means for Solving the Problems) The present invention comprises a fixed electrode having a contact and a resistor disposed to surround the contact in a metal container filled with an insulating gas. a fixed electrode-side shield, and a movable electrode that is disposed opposite to the contact and can freely come into contact with and separate from the contact;
In the disconnector configured to allow electric current to flow through the fixed electrode side shield, a cover is provided on the contact, and an insulation is provided between the contact cover and the fixed electrode side shield made of the resistor. The movable electrode side distal end of this insulator is configured to protrude further toward the movable electrode than the distal end portions of the contactor and the contactor cover.

(Function) According to the disconnector of the present invention, by disposing an insulator between the contact cover and the fixed electrode side shield made of a resistor, the distance between the two can be reduced, and the disconnector can be made smaller.

(Example) Hereinafter, an example of the present invention will be specifically described based on FIGS. 1 and 2. Incidentally, the same members as those of the conventional type shown in FIGS. 3 to 10 are designated by the same reference numerals, and the explanation thereof will be omitted.

Configuration of this embodiment* In this embodiment, as shown in FIG.
A contact cover 30 is disposed to surround the fixed electrode contact 10, and a fixed electrode shield 31 made of a resistor is disposed roughly outside of the contact cover 30. A ring-shaped metal electrode 32 is disposed at the tip of the fixed electrode side shield 31.

Further, an insulator 33 is disposed between the contactor cover 30 and the fixed electrode side shield 31 made of a resistor. The insulator 33 is configured such that its movable electrode side tip 33a protrudes toward the movable electrode from the movable electrode side tip portions of the fixed electrode side contact 10 and the contact cover 30.

Effect of this embodiment* In the disconnector of this embodiment which has such a configuration, as shown in FIG. Furthermore, the movable electrode 9
The tip of the fixed electrode is made of a resistor (when it comes out from inside the mold side shield 31, it is re-ignited between the movable electrode 9 and the metal electrode 32 disposed at the tip of the fixed electrode side shield 31, and is re-ignited). An arc 34 is formed.

A restriking current due to this restriking arc 34 flows within the fixed electrode side shield 31 made of a resistor.

At this time, a voltage drop occurs in the fixed electrode side shield 31 made of a resistor along this current path.

A voltage is applied between the fixed electrode side shield 31 made of a resistor, the fixed electrode side contact 10 and the contact cover 30, but there is no insulation between the contact cover 30 and the fixed electrode side shield 31. Since the body 33 is provided, there is no need to provide a gap between the two.

As a result, the contactor cover 30 and the fixed electrode side shield 31
The gap 2'' between the two can be made much smaller than in the past.

Further, since the movable electrode side tip 33a of the insulator 33 is configured to protrude more toward the movable electrode than the movable electrode side tip portions of the fixed electrode side contact 10 and the contact cover 30, as shown in FIG. Insulating effects can also be obtained in the area shown in Chuai 5.

*Other embodiments* The present invention is not limited to the embodiments described above, and the insulator disposed between the contact cover and the fixed electrode side shield consisting of a resistor may be placed in close contact with both. They may be arranged at intervals, or may be arranged at appropriate intervals. In either case, the distance between the contact cover and the fixed electrode side shield made of a resistor can be significantly reduced compared to the conventional case.

[Effects of the Invention] As described above, according to the present invention, a cover is provided on the contact, an insulator is provided between the contact cover and the fixed electrode side shield made of a resistor, and the insulator is By configuring the tip of the body on the movable electrode side to protrude further toward the movable electrode than the tip of the contact and the contact cover, a fixed electrode consisting of a fixed electrode side contact and a resistor is constructed. It is possible to provide a disconnector that enables downsizing of equipment by shortening the distance between the electrode side shield and the shield.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the disconnector of the present invention, and FIG.
The figure is a cross-sectional view showing the action of the disconnector shown in Figure 1, Figure 3 is a partial cross-sectional view showing the configuration of a conventional disconnector, Figure 4 is an approximate equivalent circuit for interrupting charging current by the disconnector, The figure shows the insulation recovery characteristics between the poles of a disconnector, Figure 6 shows the voltage waveform caused by restriking when charging current is cut off, and Figure 7 shows a partial cross section showing the state of restriking in a conventional disconnector. 8 is a diagram showing the restriking surge voltage, FIG. 9 is a sectional view showing another example of a conventional disconnector, and FIG. 10 is a diagram showing a restriking occurrence state in the disconnector of FIG. 9. FIG. 1... Metal container, 2... I8 edge gas, 3... Insulating spacer, 4... Conductor, 5... Conductor, 6... Fixed electrode, 7... Fixed electrode side metal Shield, 8... Resistor, 9... Movable electrode, 10... Fixed electrode side contact, 11... Movable electrode side contact, 12... Movable electrode side metal shield, 13... - Insulator, 14... Power supply voltage, 15... Short circuit impedance, 16... Capacitance of power supply side equipment, 17... Inductance of power supply side line, 18... Capacitance of load line, 19
... Load side line inductance, 20... Disconnector, 21... Load side voltage waveform, 22... Power supply side voltage waveform, 23... Re-ignition arc, 24... High frequency overvoltage, 25...Side shield to the fixed voltage 1 consisting of a resistor, 2
6... Metal electrode, 27... Discharge arc, 28...
Re-ignition arc, 30... Contactor cover, 31... Fixed electrode side shield consisting of resistor, 32... Metal electrode, 33... Insulator, 34... Re-ignition arc. Fig. 2 Fig. 3 = Fig. 4 Fig. 5 Blade No. 6 Fig. 7 Fig. 8 Fig. 9

Claims (1)

[Claims] A fixed electrode having a contact in a metal container filled with an insulating gas, a fixed electrode side shield consisting of a resistor disposed to surround the contact, and arranged opposite to the contact, and , a disconnector comprising a movable electrode that can freely come into contact with and separate from the contact, and configured to allow a restriking discharge current to flow through the fixed electrode side shield during the opening and closing process, wherein a cover is provided on the contact. An insulator is provided between the contact cover and the fixed electrode side shield made of the resistor, and the tip of the insulator on the movable electrode side is connected to the tip of the contact and the contact cover. A disconnector characterized in that it is configured to protrude toward a movable electrode side.