JPH01307120A - Disconnecting switch - Google Patents

Abstract

PURPOSE:To miniaturize the fixed electrode side shield and thus miniaturize the overall apparatus, by electrically connecting one end of the fixed electrode side shield consisting of a plurality of respective divided resistors to the fixed electrode and providing a ring-shaped metal electrode on the other end thereof. CONSTITUTION:One end of a fixed electrode side shield 30, consisting of a plurality of respective divided resistors, is electrically connected to a fixed electrode 6, and the other end is provided with a ring-shaped metal electrode 31. By constructing the fixed electrode side shield 30 from divided parts in this manner, each resistor can be manufactured homogeneously, and by providing a ring-shaped metal electrode 31 at the end of the fixed electrode side shield 30 constructed from the divided parts, the current density in the vicinity of the reignition current flowing-in point can be made homogeneous. Thus, the fixed electrode side shield 30 and hence the overall 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. 6 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 disposed on the conductor 4 connected to the fixed electrode terminal, and a resistor 8 is further provided so as to surround the fixed electrode contact 10. A metal shield 7 on the fixed electrode side is disposed on the fixed electrode side.

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 arranged inside the conductor 5 and is configured to be driven by an insulating rod 13. has been done. 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 @ (not shown) for operation.
This operating mechanism performs opening and closing operations of the disconnector.

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

Here, if the distributed capacitance and the inductance of the divider 5 of the line, transformer, etc. are approximately expressed as lumped capacitance and lumped inductance, respectively, and the photoelectric current switching circuit of the line is expressed as an approximate equivalent circuit, for example, ,
It will look like Figure 7.

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. 6, 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. 7 is cut off using a disconnector having such characteristics, a voltage waveform as shown in FIG. 9 is obtained. That is, in FIG. 9, a solid line 21 shows the voltage waveform at point "a"' in FIG. 7, and a broken line 22 shows the voltage waveform on the power supply side.

The difference between the solid line 21 and the broken line 22 is the inter-mold pressure 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 immediately 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 9, C, D, E, 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. 10 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 a disconnector as shown in Fig. 6, 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 imaging occurs in the circuit with capacitances 16 and 18 and inductances 17 and 19 shown in FIG. As shown in Figure 11, high frequency overvoltage 2
4 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 Fig. 6,
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 case of suppressing the high frequency overvoltage that occurs when the disconnector shown in FIG. The resistor 8 must be made longer. Therefore, the sixth
There was a problem in that the length L from the fixed electrode 6 to the tip of the metal shield 7 on the fixed electrode side shown in the figure could not be shortened, resulting in an increase in the size of the entire disconnector.

Therefore, in order to improve this point,
A disconnector as shown in Publication No. 32 has been proposed. That is, as shown in FIG. 12, a fixed electrode 6 and a movable electrode 9 are arranged 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 the fixed electrode. This 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 its 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,
It is configured to have a function of making the electric field between both shields 25, 12 uniform and increasing the withstand voltage between them.

In addition, in the disconnector shown in FIG. 12, 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 contact between the movable electrode 9 and the metal electrode 26 formed at the tip of the fixed electrode side shield made of a resistor is caused. discharge between
A discharge arc 27 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.

Roughly speaking, 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 fixed electrode side shield 25 is re-ignited, 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. 13, the voltage applied to the fixed electrode side shield 25 made of a resistor at the time of restriking is shared by the length 1 from the region where restriking occurs to the end. In other words,
Even in the curved part of the fixed electrode side shield 25 made of a resistor,
Since the voltage can be shared, the axial length 2 of the fixed electrode side shield 25 made of a resistor can be shortened.

In general, since the metal shield 7 on the fixed electrode side shown in FIG. 6 is not required, the length L in FIG. 6 can be shortened, and the disconnector can be made smaller.

(Problems to be Solved by the Invention) However, the disconnectors shown in FIGS. 12 and 13 have the following problems.

That is, as shown in FIG. 14, the restriking that occurs between the movable electrode 9 and the fixed electrode side shield 25 occurs at the shortest distance portion (Q-R) where the electric field strength between them is the greatest. ), and a restriking arc 28 is formed.

Then, the restriking current spreads from the generation point Q of the restriking arc 28 through the fixed electrode side shield 25 made of a resistor, and flows like a current path P.

Therefore, in the fixed electrode side shield 25 made of a resistor, the current density is highest at the inflow point Q of the restriking arc current and gradually decreases along the current path.

In this way, the potential distribution in the fixed electrode side shield 25 made of a resistor is not uniform, and the potential valve and the burden near the inflow point of the restriking arc current become large, so the fixed electrode side made of a resistor There was a problem that the shield 25 would be destroyed.

Roughly speaking, even if the material of the resistor constituting the fixed electrode side shield 25 is not uniform, the potential distribution of the fixed electrode side shield 25 will not be uniform.

However, it is extremely difficult to manufacture the cylindrical fixed electrode side shield 25 as shown in FIGS. 12 and 13 in one piece and uniformly.

The present invention was proposed to eliminate the above-mentioned drawbacks, and its purpose is to equalize the potential sharing of the fixed electrode side shield made of a resistor, and to reduce the size of the fixed electrode side shield. It is an object of the present invention to provide a disconnector that enables miniaturization of the entire device.

[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 is movable toward and away from the contact; In a disconnector configured to allow flow to flow through the side shield, the fixed electrode side shield made of the resistor is divided into a plurality of pieces, and one end of each divided fixed electrode side shield is connected to the fixed electrode side shield. A ring-shaped metal electrode is provided at the other end.

(Function) According to the disconnector of the present invention, by dividing the fixed electrode side shield and configuring it, individual resistors can be manufactured homogeneously, and the fixed electrode side shield configured by dividing the fixed electrode side shield. By disposing a ring-shaped metal electrode at the tip of the re-ignition current, it is possible to equalize the current density near the restriking current inflow point.

(Example) Hereinafter, an example of the present invention will be specifically described based on FIGS. 1 to 3. Note that the same members as those of the conventional type shown in FIGS. 6 to 14 are designated by the same reference numerals, and explanations thereof will be omitted.

Configuration of this embodiment* In this embodiment, as shown in FIG.
A fixed electrode side shield 30 made of a resistor is disposed so as to surround the fixed electrode side contactor 10. The fixed electrode side shield 30 is divided into a plurality of pieces in the circumferential direction as shown in FIG.
The tip of the other end is electrically connected to the
As shown in FIG. 2(B), a ring-shaped metal electrode 31 is provided.

Effect of this embodiment* In the disconnector of this embodiment having such a configuration, the potential distribution at the time of restriking in the fixed electrode side shield made of a resistor can be made uniform as follows. .

That is, as shown in FIG. 3, when the charging current is cut off, the movable electrode 9 and the fixed electrode contact 10 are opened, and the tip of the movable electrode 9 is roughly divided into a plurality of pieces. When exiting from the inside of the fixed electrode side shield 30 made of a resistor,
Re-ignition occurs between the movable electrode 9 and the metal electrode 31 disposed at the tip of the fixed electrode side shield 30, and a re-ignition arc 32 is formed.

The restriking current due to this restriking arc 32 is generated by the metal electrode 3
Since the current flows uniformly into the divided resistor from around 1, the current density near the restriking current inflow point is made more uniform compared to the conventional case where the current flows only from the restriking arc generation point. can do.

Further, since the fixed electrode side shield 30 is divided into a plurality of pieces, each resistor is smaller than the conventional one, and it is easy to manufacture them homogeneously. As a result, at the time of restriking, the potential distribution in the divided fixed electrode side shield 30 can be made more uniform than in the past.

Furthermore, as shown in FIG. 2, the fixed electrode side shield 30
Since the distance between the plurality of divided resistors constituting the resistor can be made small, both shields 30 can be
．． Disturbance in the electric field distribution between 12 can be reduced. That is, the withstand voltage between both shields 30.12 can be maintained.

*Other embodiments Note that the present invention is not limited to the embodiments described above, and as shown in FIGS. 4 and 5 (A>(B)), a resistor body divided into a plurality of The periphery of the fixed electrode side shield 40 composed of the following may be integrally covered with an insulator 41.

In this case as well, not only the same effects as in the above embodiment are obtained, but also the fixed electrode side shield 40 is reinforced by the insulator 41, so its strength is greatly improved.

"Effects of the Invention" As described above, according to the present invention, the fixed electrode side shield made of a resistor is divided into a plurality of pieces, and one end of each divided fixed electrode side shield is connected to the fixed electrode side shield made of a resistor. By the simple means of electrically connecting to the electrode and arranging a ring-shaped metal electrode at the other end, the potential distribution of the fixed electrode side shield made of a resistor can be made uniform, and the fixed electrode side shield can be made smaller. Therefore, it is possible to provide a disconnector that makes it possible to downsize the entire device.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of the disconnector of the present invention, and FIG.
Figure (A) is a sectional view taken along line A-A of the fixed electrode side shield used in the disconnector shown in Figure 1, (B) is its view taken along line B-B, and Figure 3 is shown in Figure 1. FIG. 4 is a cross-sectional view showing another embodiment of the present invention; FIG. 5 is a cross-sectional view of the fixed electrode side shield shown in FIG. Fig. 6 is a partial sectional view showing the configuration of a conventional disconnector, Fig. 7 is an approximate equivalent circuit for interrupting charging current by a disconnector, and Fig. 8 is a disconnection diagram. Figure 9 shows the voltage waveform caused by restriking when the charging current is cut off; Figure 10 is a partial cross-sectional view showing the state in which restriking occurs in a conventional disconnector; FIG. 11 is a diagram showing a restriking surge voltage, FIG. 12 is a sectional view showing an example of loosening of a conventional disconnector, and FIG. 13 is a sectional view showing a restriking occurrence state in the disconnector of FIG. 12. Fig. 14 is a sectional view showing the action in Fig. 13. 1... Metal container, 2... Insulating 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,
DESCRIPTION OF SYMBOLS 11...Movable electrode side contactor, 12...Movable electrode side metal shield, 13...Insulator, 14...Power supply voltage, 15...Short circuit impedance, 16...Power supply side equipment Capacitance, 17... Inductance of power supply line, 18... Capacitance of load line, 19.
...Inductance of the load side line, 20...Disconnector,
21... Load side voltage waveform, 22... Power supply side voltage waveform, 23... Re-ignition arc, 24... High frequency overvoltage,
25...Fixed electrode side shield consisting of a resistor, 26.
...Metal electrode, 27...Discharge arc, 28...Re-ignition arc, 30...Fixed electrode side shield consisting of a plurality of divided resistors, 31...Metal electrode, 32...
Re-ignition arc, 40... Fixed electrode side shield consisting of a plurality of divided resistors, 41... Insulator. (A) 52 Figure No. 3 = Whistle 4 / -40 (A) (B) 15': No. 6 = 17 Figure 48 = Answer 9 = R = 10: 511 Illustration 12 - Figure 13

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 cause a restriking discharge current to flow through the fixed electrode side shield during the opening and closing processes, comprising the resistor. The fixed electrode side shield is divided into a plurality of pieces, one end of each of the divided fixed electrode side shields is electrically connected to the fixed electrode, and a ring-shaped metal electrode is arranged at the other end. A disconnector featuring: