JP2003169410A - Gas insulated switchgear - Google Patents

Abstract

[PROBLEMS] To provide a gas insulated switchgear capable of reducing global environmental load by employing an insulating gas having a reduced global warming potential (GWP). SOLUTION: A sealed container, a connection conductor provided through the sealed container in an airtight manner, a switch connected to the connection conductor in the sealed container, and a main component sealed in the sealed container, Is an insulating gas which is a fluorocarbon (perfluorocyclocarbon), and a switch having a contact that generates an arc when opened and closed among the switches in the sealed container is a vacuum switch having a vacuum container for accommodating the contact. It is a vessel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas insulated switchgear capable of reducing the load on the global environment by adopting an insulating gas having a reduced global warming potential (GWP).

[0002]

2. Description of the Related Art A gas-insulated switchgear is a device used to distribute power received from a bus bar to various load devices and other electric rooms. In FIG. 4, the structure of the conventional gas insulated switchgear is shown. In FIG. 4, 1 and 3 are hermetically sealed containers in which an insulating gas SF ₆ is enclosed. A busbar 8a, 8b, 8c is provided in the hermetically sealed container 3 and a busbar disconnector 4 which is provided to hermetically penetrate the hermetically sealed container 3 to connect and disconnect the busbars 8a, 8b, 8c and the busbar side main circuit conductor 8. And are provided. In the sealed container 1, there are bus bars 8a, 8b, 8c.
A busbar side main circuit conductor 8 for connection with the load side main circuit conductor 9 for connection with the power transmission cable 2a to the load;
A ground switch 5 that grounds the load-side main circuit conductor 9, a power receiving disconnector 6 that connects and disconnects the load-side main circuit conductor 9 and the power transmission cable 2a, and a hermetically sealed container 1 are provided to hermetically penetrate the load. The bushing 2 that connects the side main circuit conductor 9 to the power transmission cable, the main circuit switch 10 that connects and disconnects the bus side main circuit conductor 8 and the load side main circuit conductor 9, and the main circuit switch 10 is sealed in vacuum. A vacuum arc extinguishing chamber 7 is provided.

According to the above configuration, the ground switch 5,
Power receiving disconnector 6, vacuum arc extinguishing chamber 7, busbar disconnector 4, busbar 8
Since a, 8b, 8c and the bus-side main circuit conductor 8 and the load-side main circuit conductor 9 connecting them are arranged in the sealed container 1 or the sealed container 3 in which SF ₆ gas is sealed, Due to the high insulation performance of SF ₆ gas, it is possible to reduce the distance between the phases and the ground, and it is possible to obtain a gas-insulated switchgear with a reduced size.

[0004]

However, in the conventional gas-insulated switchgear described above, the SF that has a global warming potential (GWP) of 23900 times that of CO ₂ in 100 years of evaluation as an insulating gas. _Since it uses a large amount of ₆ gas, there was a problem that it seriously affects the global environment.

Further, according to the protocol of the Kyoto Conference on Global Warming Prevention (COP3) in 1997, SF ₆ gas is included in the reduction target gas, and its use as an insulating gas will be restricted in the future. There is.

The present invention has been made in order to solve the above problems, and has a large global warming potential (GW).
An object of the present invention is to provide a gas-insulated switchgear that adopts an insulating gas with reduced P), enables a reduction in global environmental load, and has a high withstand voltage performance equivalent to that when SF ₆ gas is used.

[0007]

To achieve the above object, the present invention is a gas-insulated switchgear having the following construction. That is, (1) the gas-insulated switchgear includes a hermetically sealed container, a connecting conductor provided to hermetically penetrate the hermetically sealed container, a switch connected to the connecting conductor in the hermetically sealed container, and the hermetically sealed container. A switch having a contact that generates an arc when the switch is opened and closed, and a vacuum container that houses the contact. There is.

(2) The main component of the insulating gas may be perfluorocarbon.

(3) The insulating gas may be a gas containing CF ₄ .

(4) The insulating gas is CF ₄ , N ₂ , CO ₂
And a gas containing one selected from the group consisting of air.

(5) The insulating gas may be a gas containing c-C ₄ F ₈ .

(6) The insulating gas is c-C ₄ F ₈ and N ₂ ,
It may be a gas containing CO ₂ and one selected from the group consisting of air.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. FIG. 1 is a side sectional view showing an example of a power receiving system provided with a combination of the gas insulated switchgear of the present invention. This power receiving system is 2
Gas-insulated switchgear A and B of the stand, and conductor C for electrically connecting gas-insulated switchgear A and B to an external circuit,
A housing D for storing these is provided. Each of the gas insulated switchgear A and B has a sealed container 10 or 20.
And a connection conductor 30 provided to hermetically penetrate the sealed containers 10 and 20, and various switches 41, 42, 43, 44 and 45 connected to the connection conductor 30 in the sealed containers 10 and 20.
And an insulating gas 50 which is enclosed in the sealed containers 10 and 20 and at least a main component of which is a fluorocarbon compound.

The first gas-insulated switchgear A is a sealed container 20.
And the top wall of the sealed container 20 has a bus bar 2 at one end.
A busbar connecting bushing 25 that is connected to the busbar 6 and extends airtightly through the hermetically sealed container 20 and is connected to the busbar side conductor 22 at the other end in the hermetically sealed container 20 is provided. A gas partition bushing 21 is hermetically provided on the bottom wall of the hermetic container 20, a rotating conductor 23 is rotatably supported at one end of the bushing 21 inside the hermetic container 20, and the other end of the bushing 21 is downward. The airtightly penetrates the sealed container 10 of the second gas-insulated switchgear B arranged in the above, and enters the inside thereof, and is connected to the switch in the sealed container 10 described later.

Further, on the front side (left side in FIG. 1) of the sealed container 20, there are provided a grounding switch 24 composed of a vacuum switch and a disconnecting / grounding drive mechanism 32 for operating it. The rotary conductor 23 pivotally attached to the gas section bushing 21 comes into contact with the busbar side conductor 22 (shown by a solid line in FIG. 1), and the rotary conductor 23 is connected to the ground switchgear 24 in a disconnection position. (Shown by a broken line in FIG. 1), the busbar-side disconnector is configured in cooperation with the busbar-side conductor 22.

In the sealed container 20 of the gas insulated switchgear A
Is an electrically insulating gas 50, SF ₆Gas free,
Main component is fluorocarbon compound, for example perfluorocar
Insulating gas, which is a bon, is enclosed. Used in this invention
The insulating gas 50 to be obtained is fluorinated such as perfluorocarbon.
Carbon compound gas or at least the main component is fluorocarbon
It is a gas that is an elementary compound. Also, preferably CF_Four
Gas, CF_FourWith N as the main component₂, CO₂And from the air
An insulating gas containing at least one selected from the group c-
C_FourF₈Gas, c-C_FourF₈Gas as the main component N₂, CO₂
And at least one selected from the group consisting of air
It is an insulating gas. In either case, ensure insulation performance
Therefore, CF_FourGas and c-C_FourF₈1 by volume of gas
It is desirable to mix 0% or more.

As described above, the first gas-insulated switchgear A has the hermetically sealed container 20, the connecting conductor 30 provided through the hermetically sealed container 20 in an airtight manner, and the connecting conductor 30 in the hermetically sealed container 20. It is provided with various switches 41 and 42 connected. In the illustrated first gas-insulated switchgear A, a connecting conductor 30 in which a busbar connecting bushing 25 and a gas dividing bushing 21 are provided to hermetically penetrate the sealed container 20.
Is. Further, the busbar-side disconnector constituted by the busbar-side disconnector 22 and the rotating conductor 23 is the first switch 41 connected to the connection conductor 30 in the first sealed container 20. Further, the grounding switch 24 provided on the front side (left side in FIG. 1) of the sealed container 20 is the second switch 42. Since the first switch 41 (busbar-side disconnector 22 and rotary conductor 23) is a disconnector, no arc is generated between the contacts during the opening / closing operation and the insulating gas 50 is not deteriorated.
The contacts of the switch 41 are directly arranged in the insulating gas atmosphere of the sealed container 20. However, the second switch 42 (grounding switchgear 24) is a switch with a closing capacity, and an arc is generated between the contacts during the closing operation, which deteriorates the insulating gas 50 and lowers the withstand voltage. The second switch 42 is a vacuum switch whose contacts are arranged in the vacuum container 60.

In the second gas-insulated switchgear B, the same electrically insulating gas 50 as that of the first gas-insulated switchgear A is filled with a fluorocarbon compound whose main component is, for example, perfluorocarbon containing perfluorobutane. Sealed container 10
On the top wall of the sealed container 10, a gas section bushing 21 connected to the sealed container 20 of the first gas-insulated switchgear A is provided so as to extend through the sealed container 10 in an airtight manner. ing. A movable electrode (not shown) of the vacuum circuit breaker 14 is connected to an end of the gas compartment bushing 21 inside the sealed container 10 via a flexible conductor 11. The vacuum circuit breaker 14 is supported in the sealed container 10 by a supporting structure (not shown), and the insulating operating rod 1
A circuit breaker operating mechanism 31 and a disconnecting / grounding mechanism driving device 39 are arranged in front of the sealed container 10 so that the sealed container 10 can be operated from the front part (left side in FIG. 1) by 3.

A terminal 12 is provided on the fixed electrode side in the vacuum circuit breaker 14, and the sealed container 1 is attached to the terminal 12.
The cable connecting bushing 15 provided on the bottom wall of the No. 0 pivotally mounts a rotatable conductor 16 that is separated from and attached to the cable connection bushing 15. The rotatable rotating conductor 16 is in a closed position (solid line position in FIG. 1) for electrically connecting the vacuum circuit breaker 14 and the cable connecting bushing 15 by an operating mechanism (not shown).
And a ground position (a broken line position in FIG. 1) in contact with the ground side conductor 17 of the vacuum switch 18 for grounding switching, apart from the vacuum circuit breaker 14. The outer end of the cable connection bushing 15 is connected to a conductor C which is a power receiving cable having a current transformer.

As described above, the second gas-insulated switchgear B is provided with the hermetically sealed container 20, the connecting conductor 30 provided through the hermetically sealed container 20 in an airtight manner, and the connecting conductor 30 in the hermetically sealed container 20. It has various switches 43, 44, 45 connected to it. In the illustrated second gas-insulated switchgear B, the gas division bushing 21 and the cable connection bushing 15 are the connection conductors 30 provided so as to penetrate the hermetically sealed container 10 in an airtight manner. Further, the vacuum circuit breaker 14 is the third switch 43 connected to the connection conductor 30 (the gas division bushing 21 and the cable connection bushing 15) in the sealed container 10, and the vacuum switch for grounding 18 is the sealed container 1.
A fourth switch 44 connected to the connection conductor 17 in the zero position, and a ground side disconnector constituted by the ground side conductor 17, the fixed side conductor 12 of the vacuum circuit breaker 14 and the rotating conductor 16 is a second switch. Fifth switch 45 connected to the connection conductor 30 (cable connection bushing 15) in the sealed container 10 of
Is.

The fifth switch 45 (grounding side disconnector) is a disconnector, and arc is not generated between the contacts during its opening / closing operation, and the insulating gas is not deteriorated. It is arranged as it is in the insulating gas atmosphere of the sealed container 10. However, the third switch 43 (vacuum circuit breaker 14) and the fourth switch 44 (grounding vacuum switch 18) generate an arc between the contacts during the opening and closing operation, otherwise insulating gas is generated. Since the third switch 43 (vacuum circuit breaker 14) and the fourth switch 44 (grounding vacuum switch 18) are deteriorated to lower the withstand voltage, the contacts of the third switch 43 (vacuum circuit breaker 14) and the vacuum switch 18 for grounding are arranged in a vacuum container. It is configured as a switch.

[0022] As described above, if only at least the main component from the SF ₆ gas insulation gas in the gas insulated switchgear is replaced with an insulating gas is a fluorocarbon-based compound, switchgear gas insulated switchgear Insulation gas is decomposed by the arc generated at the contact of, and decomposition products are generated,
The breakdown voltage of the conductive particles or dust, which is a decomposition product, lowers the withstand voltage performance, and the reliability of the gas-insulated switchgear is significantly impaired. For this reason, it has hitherto been believed by those skilled in the art that fluorocarbon gas is not suitable as an insulating gas for a gas-insulated switchgear. Focusing on the property of generating a decomposition product, it has been proposed to use it as a monitor gas for detecting an abnormality in a gas-insulated electric device, but an example used as an insulating gas is not known.

According to the present invention, contrary to the belief of those skilled in the art, the gas insulated switchgear A and B uses SF ₆ gas at all as the electrically insulating gas sealed in the sealed containers 20 and 10. Instead, a gas containing at least a main component of a fluorocarbon compound, such as an insulating gas of perfluorocarbon, is enclosed. In addition, among the switches provided in the gas insulated switchgear, a vacuum switch is used as a switch that has a contact that may generate an arc during opening and closing operation, and the insulation gas is removed by covering the contact with a vacuum container. It is designed so that it will not be decomposed by the arc. Therefore, the global warming potential (GWP) of the insulating gas used in the gas-insulated switchgear can be made extremely low as compared with the conventional gas-insulated switchgear to significantly reduce the global environmental load. It is possible to obtain high withstand voltage performance that is almost the same as that when gas is used.

FIG. 2 shows a gas-insulated switchgear according to the present invention.
C-C_FourF₈Gas and SF₆Flat plate in gas
Filled with DC withstand voltage (kV) between poles in a sealed container
Distance (mm) between generated gas pressure (atm) and plate electrode
The Pd value (atm-mm), which is the product of
It is a graph which shows the result of having changed to 3 and measured. Gu
The horizontal axis of the rough represents the Pd value (atm-mm), and the vertical axis is the flat surface.
Shows the DC withstand voltage (kV) between plate electrodes and measures the withstand voltage
Is a conventional SF₆The measured gas value is shown as a dashed line.
And C-C which can be used in the present invention_FourF₈Gas measurement value is a solid line
It is represented by. As is clear from the graph of FIG.
_FourF₈Gas withstand voltage is SF regardless of Pd value ₆Gas electric resistance
It is several tens of percent larger than the pressure and proportional to the Pd value.
_FourF₈Gas is an excellent insulating gas.

FIG. 3 shows the DC withstand voltage (kV) between the flat plate electrodes in c-C ₄ F ₈ gas and SF ₆ gas when the Pd value is 4.6 (atm-mm) in N ₂ gas. 5 is a graph showing the results of measurement by changing the gas concentration (volume%) of each from 0 to 100. The horizontal axis of the graph represents the volume ratio (%) of the c-C ₄ F ₈ gas and SF ₆ gas added to the N ₂ gas, and the vertical axis represents the DC withstand voltage (kV).
The solid line represents the measured values of c-C ₄ F ₈ gas, the broken line represents the measured values of SF ₆ gas. As is clear from the graph of FIG. 3, the DC withstand voltage increases as the concentration of N ₂ decreases in both c-C ₄ F ₈ gas and SF ₆ gas, and N ₂ is about 5
When the amount exceeds 0%, the withstand voltage of c-C ₄ F ₈ gas becomes smaller than that of SF ₆ gas, but it still has sufficient withstand voltage for use as an insulating gas in a gas insulated switchgear. ing.

From these facts, as the gas mixed with the c-C ₄ F ₈ gas and the SF ₆ gas, the concentration of the mixed N ₂ gas can be arbitrarily set within the range where the withstand voltage required for the gas insulated switchgear can be secured. I know you can change it. Similar results can be obtained by using CO ₂ or air, or N ₂ , CO ₂ and air can be arbitrarily selected and used in combination. When these gases are added, c-C ₄ F ₈ gas and S
The amount of F ₆ gas used is reduced, and the global environmental load can be further reduced.

[0027]

As described above, according to the present invention,
The following effects are achieved. (1) The gas-insulated switchgear includes a hermetically sealed container, a connecting conductor provided to hermetically penetrate the hermetically sealed container, a switch connected to the connecting conductor in the hermetically sealed container, and a hermetically sealed container in the hermetically sealed container. A switch which is enclosed and has at least a main component of a fluorocarbon-based compound, and which has a contact that generates an arc when opening and closing of the switch, and a vacuum container that accommodates the contact. , SF ₆ gas is not used, the global environmental load can be reduced, the gas is prevented from being decomposed by an arc, and the deterioration of withstand voltage performance due to conductive particles or dust which is a decomposition product is eliminated, which is high. The reliability can be obtained.

(2) Since the main component of the insulating gas is perfluorocarbon, the reliability of the gas insulated switchgear is improved.

(3) Since the insulating gas is a gas containing CF ₄ , SF ₆ gas is not used, and the load on the global environment can be reduced.

(4) The insulating gas is CF ₄ , N ₂ , CO ₂
Since it is a gas containing one selected from the group consisting of and and air, SF ₆ gas is not used, and the global environmental load can be reduced.

(5) Since the insulating gas is a gas containing c-C ₄ F ₈ , SF ₆ gas is not used, and the load on the global environment can be reduced.

(6) The insulating gas is c-C ₄ F ₈ and N ₂ ,
Since it is a gas containing one selected from the group consisting of CO ₂ and air, SF ₆ gas is not used and the global environmental load can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a gas-insulated switchgear according to the present invention.

FIG. 2 is a diagram showing the results of measuring DC withstand voltage between flat plate electrodes in SF ₆ gas and c-C ₄ F ₈ gas.

FIG. 3 is a mixed gas of SF ₆ gas and N ₂ gas and c-
Is a diagram illustrating a DC withstand voltage measurements between plate electrodes in the mixed gas of C ₄ F ₈ gas and N ₂ gas.

FIG. 4 is a cross-sectional view of a conventional gas-insulated switchgear using SF ₆ gas.

[Explanation of symbols]

10, 20 sealed container, 30 connecting conductor, 40 switch, 50 insulating gas, 60 vacuum container.

Claims (6)

[Claims] 1. A hermetically sealed container, a connection conductor provided to hermetically penetrate the hermetically sealed container, a switch connected to the connection conductor in the hermetically sealed container, and at least enclosed in the hermetically sealed container. A gas-insulated switchgear comprising an insulating gas whose main component is a fluorocarbon compound, and a switch having a contact point that generates an arc when the switch is opened and closed, and a vacuum container containing the contact point. 2. The gas insulated switchgear according to claim 1, wherein the main component of the insulating gas is perfluorocarbon (PFC). 3. The gas insulated switchgear according to claim 1, wherein the insulating gas is a gas containing CF ₄ . 4. The gas insulated switchgear according to claim 3, wherein the insulating gas is a gas containing one selected from the group consisting of N ₂ , CO ₂ and air. 5. The gas insulated switchgear according to claim 1, wherein the insulating gas is a gas containing c—C ₄ F ₈ . 6. The gas insulated switchgear according to claim 5, wherein the insulating gas is a gas containing one selected from the group consisting of N ₂ , CO ₂ and air.