JP2001218318A - Compound gas-insulated switchgear, electric power station having compound gas-insulated switchgear, renewing method for electric power station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly reliable electric power station, etc., in which there is hardly caused dielectric breakdown on the side of air-insulated main bus-bars. SOLUTION: An overhead transmission line 5 is supported by a dead-end tower 26 via the use of a suspension insulator 27 and a long-rod insulator 28, and is connected to the line-side bushing 16 of a line unit 2. Air-insulated main bus-bars 7, 8 are supported by an iron structure 30 via suspension insulators 31 and long-rod insulators 32 (the suspension insulators, long-rod insulators, etc., for supporting the main bus-bars 7 are not shown in the figure), and connected to the main bus-bar side bushings 17 of the line unit 2 by aerial connecting lines 19, 20, respectively. The dielectric strength of the main bus-bars 7, 8 and the main bus-bar side bushings 17 of the line unit 2 is 10% or more higher than that of the line-side bushing 16 of the line unit 2. Since the dispersion σ of the dielectric breakdown of the bus-bars 7, 8 is lower than 5%, an insulation level difference >=10%=2σ is made, and dielectric breakdown on the side of the bus-bars 7, 8 is prevented, and the reliability of insulation is enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite gas insulated switchgear used in the field of power generation and transformation of a power system, a power transmission field, and the like, an electric station having the compound gas insulated switchgear, and a method of updating an electric station. It is.

[0002]

2. Description of the Related Art FIGS. 12 to 17 show, for example, Mitsubishi Electric Technical Report Vol. 53, no. 10, 1979, 768-77
FIG. 12 shows a conventional composite gas insulated switchgear described in "500 kV Gas Insulated Composite Switchgear Delivered to Kyushu Electric Power Co., Ltd. Nishikyushu Substation" by Koichi Yamaguchi et al. FIG. 2 is a single-line diagram of a substation to which the switchgear is applied.

FIG. 13 is a side view of a substation, and FIG. 14 is a cross-sectional view of a line unit which is one of composite gas insulated switchgears. 15 is a cross-sectional view of a bushing insulator tube on the side of the line overhead transmission line of the track unit, FIG. 16 is a side view of a suspension insulator of a substation, and FIG. 17 is a side view of a long trunk insulator of the substation.

In FIG. 12, a double bus type substation 10 is shown.
1 is configured as follows. Reference numeral 102 denotes a line unit (which will be described in detail later), which is one of the combined gas insulated switchgears; 103, a transformer unit; and 104, a bus connection unit. Reference numeral 105 denotes an overhead power transmission line (hereinafter, sometimes simply referred to as a line), reference numeral 106 denotes a transformer, and reference numerals 107 and 108 denote double-bus air-insulated main buses (hereinafter, sometimes simply referred to as main buses). 119, 120, 121, 12
2,123 are aerial connection lines, 125 is an imaginary ground line (FIG. 13)
It is.

[0005] As shown in FIGS. 12 and 13, a bushing 116 on the line side of the line unit 102 (to be described in detail later) is connected to the overhead power transmission line 105 and a bushing 117 on the main bus side.
Is the air-insulated main bus 1 via the air connection wires 119 and 120
07,108.

As shown in FIG. 12, a bushing 117 on the main bus line side of the transformer unit 103 is connected to the air-insulated main bus 10 via air connection lines 119 and 120, respectively.
The bushing 118 on the transformer side is connected to the transformer 106 via an air connection line 121. The bushing 117 of the bus connection unit 104 is connected to the air-insulated main bus 107,
108.

[0007] In FIG. 13, an overhead power transmission line 105 is connected to a landing tower 126 via a suspension insulator 127 and a long trunk insulator 128.
And is connected to the bushing 116 of the track unit 102. The air-insulated main buses 107 and 108 are supported by a steel structure 130 via a suspension insulator 131 and a long trunk insulator 132 (details will be described later).
0, the bushing 1 at the center of the track unit 102
17, connected to the left bushing 117. In FIG. 13, suspension insulators, long trunk insulators, steel structures, and the like that support the air-insulated main bus 107 are omitted.

FIG. 14 shows a specific configuration of the line unit 102. The line unit 102 is a container 102 in which sulfur hexafluoride gas, which is a gas for electrical insulation, is sealed.
a and a control box 102b. The container 102a houses or attaches the following device.

In FIG. 14, reference numeral 9 denotes a disconnector on the main bus side. As shown in the figure, there are two disconnectors 9 on the left main bus side and disconnectors 9 on the inner (right) main bus side. . Each has a fixed contact portion 9a and a movable contact portion 9b, and each movable contact portion 9b is connected by a conductor 9c. Reference numeral 10 denotes a current transformer, 11 denotes a one-point cutoff unit, and 11a denotes an operation device for operating the cutoff unit 11. 12 is a line-side disconnector, 12
a is a fixed contact portion, and 12b is a movable contact portion. 13
Is a ground switch, 14 is an arrester, and 15 is a voltage transformer.

Reference numeral 116 denotes a bushing on the line side, which has an insulator tube 116a, a conductor 116b, and a terminal portion 116c. The insulator tube 116a is made of porcelain, and has flanges 116d and 116e as shown in FIG. In FIG. 15, a1 is the effective length of the insulator tube 116a, and b1 is the leakage length.

Reference numeral 117 denotes a bushing on the main bus side, which has an insulator tube 117a, a conductor 117b, and a terminal portion 117c.
The insulator 117a is made of porcelain, and the insulator 116 shown in FIG.
It is the same as a and has flanges 117d and 117e.

Reference numeral 24 denotes a conical insulating spacer, which is a movable contact portion 9b of the disconnector 9 on the main bus side and the disconnector 1 on the line side.
2 and supports the movable contact portion 12b, etc.
1 is separated from the portion in which it is accommodated and the other portion, and is gas-divided.

The suspension insulator 131 has an insulator portion 131a, metal fittings 131b and 131c, and an arc horn 131d as shown in detail in FIG. a2 is a suspension insulator 131
Is the effective length, b2 is the leakage length, and g2 is the arc horn gap length of the suspension insulator 131. The long trunk insulator 132 is shown in FIG.
As shown in detail in FIG.
And an arc horn 132c. a3 is the long trunk insulator 1
32 is the effective length, b3 is the leakage length, and g3 is the arc horn gap length of the long trunk insulator 132.

As described above, the double bus type substation 101
(FIG. 12) is provided with a line unit 102 which is a compound gas insulated switchgear for a plurality of lines, a transformer unit 103 for a plurality of transformers, a bus connection unit 104 for a bus connection, and the like. Also, two sets of air-insulated main buses 107 and 108, which are one set of three phases, a plurality of transformers 106, a plurality of overhead transmission lines 105, and aerial connection lines 119 and 12
0, 121, 122, 123, etc. are provided.

Further, the air-insulated main buses 107, 108,
Overhead transmission line 105 and aerial connection lines 119, 120, 12
In order to support 1, 122, 123, etc., a plurality of suspension insulators 127, 131 and long-stem insulators 128, 132 are provided on the anchoring tower 126 and the steel structure 130 of the substation.

By the way, in the conventional composite gas insulated switchgear such as the line unit 102, the bushing 117 on the main bus side and the bushing 116 on the line side are the same from the viewpoint of standardization. In addition, the same suspension insulators 127 and 131 and long trunk insulators 128 and 132 have been used. Therefore, the suspension insulators 127 and 131, the long trunk insulator 1
28 and 132 and bushings 116 and 117 have substantially the same dielectric strength. The effective length, leakage length, and arc horn gap length of suspension insulators, long trunk insulators, and bushing insulator tubes are almost the same.
The probability of dielectric breakdown due to salt damage, wind damage, snow damage, bird damage, etc. was at the same level.

For this reason, in the conventional substation, the suspension insulator 13 supporting the air-insulated main buses 107 and 108 due to excessive voltage duty due to lightning strike, salt damage, wind damage, snow damage, bird damage and the like.
1. There is a problem that the bushing 117 on the main bus side of the long trunk insulator 132 or the line unit 102 is broken down, the air-insulated main buses 107 and 108 are stopped, and the whole or half of the substation is stopped. I was

FIG. 18 shows, for example, Japanese Patent Application Laid-Open No. 4-47.
FIG. 7 is a side view of a conventional all-gas insulated switchgear described in JP-A-07-07. In FIG. 18, reference numeral 49 denotes an all-gas insulated switchgear (hereinafter referred to as a gas-insulated switchgear), and the main bus 5
All of them, including 1, 52, are gas-insulated.

Reference numeral 50 denotes a power cable, 51 and 52 denote main buses, and 53 denotes a disconnector on the main bus side. 54 is a current transformer, 5
5 is a circuit breaker, 56 is a line-side disconnector, 57 is a lightning arrester, 5
8 is a bushing on the track side. A line unit, a transformer unit, a bus connection unit, and the like are configured by the above-described devices, and a gas insulated switchgear is configured as a whole.

In FIG. 18, a double bus type gas insulated switchgear 49 includes a plurality of line units connected to an overhead transmission line 105, a plurality of transformer units connected to a transformer (not shown) by a power cable 50, The gas insulated switchgear 49 is configured with a bus connection unit (not shown) and the like, and the main buses 51 and 52 of the gas insulated switchgear 49 are designed to have a higher dielectric strength than the other parts.

Main bus 51 of conventional gas insulated switchgear 49
Since the constituent devices are all insulated in gas, the reinforcement of the dielectric strength of the parts 52 and 52 can be easily realized only by design in gas. Variation of insulation in gas of gas insulated switchgear is 2
%, And if the dielectric strength difference is 2σ, it becomes 4%,
Insulation reinforcement of about 4% was sufficient, and there was no problem in cost.

However, in a composite gas insulated switchgear having an air insulating portion such as a suspension insulator or a long trunk insulator, which has a large variation in dielectric strength and needs to consider salt damage, wind damage, snow damage, bird damage, etc. Inappropriate insulation strengthening concept cannot be applied. In addition, when replacing a substation with an existing air-insulated switchgear with a gas-insulated switchgear, it is necessary to completely stop the substation, so the existing air-insulated switchgear must be gas-insulated up to the main bus. It is difficult to replace this with a gas insulated switchgear.

[0023]

Since the conventional composite gas insulated switchgear is constructed as described above, an insulation breakdown accident occurs on the aerial insulated main buses 107 and 108 due to excessive duties. There was a problem that the station stopped and the power outage range of the substation became large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a composite gas insulated switchgear having high insulation reliability and an electric insulation having high insulation reliability, in which the main bus portion of the air insulation is hard to stop. The purpose is to obtain a power station and to provide a method for updating the power station.

[0025]

In order to achieve the above object, a composite gas insulated switchgear according to the present invention has first and second air-insulated bushings, and the first and second bushings are provided through the first bushing. In a combined gas-insulated switchgear connected to an air-insulated main bus and connected to electrical equipment via a second bushing, the dielectric strength of the first bushing is 10% less than the dielectric strength of the second bushing. It is characterized by being raised above. Since the variation σ of the dielectric breakdown in the air is less than 5%, by providing an insulation level difference of 10% or more of 2σ, the dielectric breakdown always occurs in the aerial part on the second bushing side, which has the lower dielectric strength. Insulation does not occur in the aerial part on the first bushing side. Therefore, the insulation reliability on the first bushing side can be improved.

In the composite gas insulated switchgear of the present invention, an insulating cylinder and a cap made of an organic material are formed, and the cap has a cap made of an organic material for a cap having a higher elasticity than the organic material. The portion is fitted on the outer peripheral portion of the insulating cylinder. Composite insulators are lighter and have higher mechanical strength than porcelain insulators, so even though their effective lengths are the same, they can be made larger in diameter. Increasing the diameter decreases the electric field intensity in the air, so that the dielectric strength against lightning surge and the like can be improved. In addition, since the cap portion is formed of a cap material having a high elasticity, the pitch of the cap portions of the cap portion can be made dense.
If the pitch of the cap of the cap is made dense, the leakage length can be lengthened even if the effective length is the same. Therefore, compared to porcelain porcelain tubes, even in the case of the same effective length, the insulation strength in the air can be easily increased by increasing the diameter, reducing the pitch of the cap of the cap portion, or using both methods together. Can be improved.

Further, an electric substation having a composite gas insulated switchgear of the present invention is provided with an air-insulated main bus, electric equipment and a composite gas insulated switchgear, and Is an electrical substation having first and second air-insulated bushings, connected to the air-insulated main bus via the first bushing, and connected to electrical equipment via the second bushing. Wherein the dielectric strength of the air-insulated main bus and the first bushing is 10% or more higher than the dielectric strength of the electrical equipment and the second bushing. Since the variation σ of the dielectric breakdown in the air is less than 5%, by providing an insulation level difference of 10% or more of 2σ, the dielectric breakdown is caused in the electrical equipment having the lower dielectric strength or the air part on the second bushing side. Is generated, and dielectric breakdown does not occur in the air-insulated main bus and the air portion on the first bushing side. Therefore, the insulation reliability of the air-insulated main bus and the first bushing side can be improved.

In the method for updating an electric substation according to the present invention, The insulation strength of the existing aerial insulated main bus is 10 times higher than before.
A main bus changing step of changing to an air-insulated main bus higher than 1%. 3. A switching device updating step of removing the existing air-insulated switching device and replacing it with the combined gas-insulated switching device according to claim 1 or 2. c. Connecting the changed air-insulated main bus and the updated combined gas-insulated switchgear. In this way, by changing to an air-insulated main bus having a dielectric strength of 10% or more higher than that of the conventional one and replacing the composite gas insulated switchgear according to claim 1 or 2, the dielectric strength of the switch is lower. Insulation breakdown occurs in the electrical equipment or the aerial part on the second bushing side, and the insulation does not occur in the aerial main bus and the aerial part on the first bushing side. Therefore, the insulation reliability on the air-insulated main bus and the first bushing side can be improved, and a highly reliable electric station can be realized.

In the method for updating an electric substation according to the present invention, the existing air-insulated main bus is a double bus, and the existing air-insulated switchgear is provided with a plurality of main buses. The process is to alternately stop the operation of the existing aerial insulated main bus and change to an aerial insulated main bus whose dielectric strength is 10% or more higher than before. The present invention is characterized in that the operation of the insulated main bus is alternately stopped, and the air insulated switchgear is replaced with a combined gas insulated switchgear. Alternately stop the air-insulated main bus, change to the air-insulated main bus whose dielectric strength is 10% or more higher than before, alternately stop the operation of the existing or changed air-insulated main bus, and stop the existing air. By replacing the insulated switchgear with a compound gas insulated switchgear, the electric station can be updated while avoiding a total stoppage.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a single line diagram of a substation to which a combined gas-insulated switchgear is applied. FIG. 2 is a side view of the substation, and FIG. 3 is a cross-sectional view of a line unit which is one of the combined gas-insulated switchgears. FIG.
Is a cross-sectional view of a bushing porcelain tube on the line side of the line unit, and FIG. 5 is a cross-sectional view of a bushing porcelain tube on the main bus side of the line unit. FIG. 6 is a side view of the suspension insulator of the substation,
FIG. 7 is a side view of the long trunk insulator of the substation.

In FIG. 1, a double bus type substation 1
It is configured as follows. Reference numeral 2 denotes a line unit (which will be described later in detail), which is one of the composite gas insulated switchgears. Reference numeral 3 denotes a transformer unit. 4 is a bus connection unit. 5 is an overhead power transmission line, 6 is a transformer, and 7 and 8 are double-bus insulated main buses. 16 is a bushing on the track side of the track unit 2, and 17 is a bushing on the main bus side of the track unit 2. 19, 20, 21, 22, 23 are aerial connection lines, and 25 is an overhead ground line (FIG. 2).

As shown in FIG. 1 and FIG.
The bushing 16 on the track side (details will be described later)
And the bushing 17 on the main bus side is connected to the aerial connection line 1.
They are connected to the air-insulated main buses 7, 8 via 9, 20.

As shown in FIG. 1, the bushings 17 on the main bus line side of the transformer unit 3 are connected to the air-insulated main buses 7 and 8 via the air connection lines 19 and 20, respectively.
The bushing 18 on the transformer side is connected to the transformer 6 via an air connection line 21. The bushing 17 of the bus connection unit 4 is connected to the air-insulated main buses 7 and 8 via the air connection wires 22 and 23.

In FIG. 2, the overhead transmission line 5 is
7 and supported by the anchoring tower 26 via the long trunk insulator 28,
It is connected to the bushing 16 on the track side of the track unit 2. The air-insulated main buses 7 and 8 are supported by a steel structure 30 via suspension insulators 31 and long trunk insulators 32 (details will be described later), and are connected to the main bus side of the line unit 2 via air connection wires 19 and 20 respectively. It is connected to each bushing 17 (center side and left side). In FIG. 2, suspension insulators, long trunk insulators, steel structures, and the like that support the air-insulated main bus 7 are omitted.

FIG. 3 shows a specific configuration of the line unit 2. The line unit 2 is composed of a container 2a and a control box 2 in which sulfur hexafluoride gas, which is a gas for electrical insulation, is sealed.
b. The container 2a houses or attaches the following device.

Reference numeral 9 denotes a disconnector on the main bus side. As shown in the figure, there are two disconnectors 9 on the left main bus side and disconnectors 9 on the inner (right) main bus side. And a movable contact portion 9b. Each movable contact portion 9b has a conductor 9
They are connected by c. Reference numeral 10 denotes a current transformer, 11 denotes a one-point cutoff unit, and 11a denotes an operation device for operating the cutoff unit 11.
12 is a line-side disconnector, 12a is a fixed contact portion, 12b
Denotes a movable contact portion. 13 is a ground switch, 14 is a lightning arrester, and 15 is a voltage transformer.

The bushing 1 on the track side is provided in the container 2a.
6. The bushings 17 on the two main buses are disposed so as to be inclined such that the distance between the ends thereof is large so that the required air insulation distance can be secured. The line-side bushing 16 has a porcelain tube 16a, a conductor 16b, and a terminal portion 16c. The insulator tube 16a is made of porcelain and has flanges 16d and 16e as shown in detail in FIG.
Note that a4 is the effective length of the insulator tube 16a, and b4 is the leakage length.

The bushing 17 on the main bus side includes an insulator tube 17
a, a conductor 17b, and a terminal portion 17c. The porcelain pipe 17a is made of porcelain, and as shown in FIG.
7d and 17e. In FIG. 5, a5 is the effective length of the insulator tube 17a, and b5 is the leakage length.

Returning to FIG. 3, reference numeral 24 denotes a conical insulating spacer which supports the movable contact portion 9b of the disconnector 9 on the main bus side, the movable contact portion 12b of the disconnector 12 on the line side, and the like. The part in which the blocking part 11 is accommodated and the other part are partitioned to separate the gas.

The suspension insulator 31 has an insulator portion 31a, metal fittings 31b and 31c, and an arc horn 31d as shown in detail in FIG. a6 is the effective length of the suspension insulator 31, b
6 is the leak length, and g6 is the arc horn gap length of the suspension insulator. The long trunk insulator 32 has an insulator portion 32a, a metal fitting 32b, and an arc horn 32c as shown in detail in FIG. a7 is the effective length of the long trunk insulator 32, b7 is the leakage length, g
7 is the arc horn gap length of the long trunk insulator 32.

As described above, in the double bus type substation 1 (FIG. 1), the line unit 2 which is a composite gas insulated switchgear for a plurality of lines, the transformer unit 3 for a plurality of transformers,
A bus connection unit 4 and the like for bus connection are provided.
Also, two sets of air-insulated main buses 7, 8, which form a set of three phases,
A plurality of transformers 6, a plurality of overhead transmission lines 5, aerial connection lines 19, 20, 21, 22, 23 and the like are provided.

Further, in order to support the air-insulated main buses 7 and 8, the overhead transmission line 5, and the air connection lines 19, 20, 21, 22, 23, etc., a plurality of suspension insulators 31 and long trunk insulators 3 are provided.
2 is provided in the dyke tower 26 and the steel structure 30 of the substation. The container 2a of the line unit 2 has two sets of bushings 17 on the main bus side connected to the two sets of air-insulated main buses 7 and 8, respectively, and one set of line sides connected to the overhead transmission line 5. Bushing 16 is provided.

Here, the suspension insulator 27 and the long trunk insulator 28 supporting the overhead transmission line 5 are the same as the suspension insulator 127 and the long trunk insulator 128 supporting the overhead transmission line of the conventional substation. The bushing 16 on the second track side is the same as the bushing 116 of the conventional track unit 102.

The effective lengths a6 and a7 of the suspension insulator 31 and the long trunk insulator 32 that support the air-insulated main buses 7 and 8 are the suspension insulator 27 and the long trunk insulator 28 that support the overhead power transmission line 5.
Is at least 10% longer than the effective length. The leakage lengths b6 and b7 of the suspension insulators 31 and the long trunk insulators 32 supporting the air-insulated main buses 7 and 8 are 10% or more of the leakage lengths of the suspension insulators 27 and the long trunk insulators 28 supporting the overhead power transmission line 5. Have been long.

The arc horn gap length g6 of the suspension insulator 31 and the long trunk insulator 32 supporting the air-insulated main buses 7 and 8
And g7 are at least 10% longer than the arc horn gap length of the suspension insulator 27 and the long trunk insulator 28 supporting the overhead transmission line 5. Accordingly, the dielectric strength of the suspension insulator 31 and the long trunk insulator 32 supporting the aerial insulated main buses 7 and 8 is more than 10% higher than the dielectric strength of the suspension insulator 27 and the long trunk insulator 28 supporting the overhead power transmission line 5. It will be.

The effective length a5 of the bushing 17 on the main bus side of the line unit 2 is at least 10% longer than the effective length a4 of the bushing 16 on the line side. The leakage length b5 of the bushing 17 on the main bus side of the line unit 2 is at least 10% longer than the leakage length b4 of the bushing 16 on the line side. That is, the air-insulated main bus 7 of the line unit 2
In addition, the dielectric strength of the bushing 17 on the side of the overhead transmission line 5 is strengthened by 10% or more than the dielectric strength of the bushing 16 on the side of the overhead transmission line 5.

Although not shown in detail, each bushing 17 on the main bus side of the transformer unit 3 for the transformer 6 shown in FIG. 1 is at least 10% more than the dielectric strength of the bushing 18 on the transformer side. Has been strengthened. Each bushing 17 of the bus connection unit 4 for bus connection shown in FIG. 1 is 10 times less than the dielectric strength of the bushing 16 on the overhead transmission line 5 of the line unit 2 and the bushing 18 on the transformer side of the transformer unit 3 for the transformer. % Has been strengthened.

As described above, the bushing 17 connected to the aerial insulated buses 7 and 8 and the suspension insulator 31 and the long trunk insulator 32 supporting the aerial insulated buses 7 and 8 all have a dielectric strength of 10% or more. ing. In this substation, if an excessive lightning surge exceeding the protection level of the lightning arrester 14 enters the substation 1 due to a lightning strike on the overhead transmission line 5, the entire substation 1 is exposed to an excessive voltage and is insulated at a weak point. It will be destroyed.

However, since the variation σ of the dielectric breakdown in the air is less than 5%, by providing an insulation level difference of 10% or more of 2σ, the side of the overhead transmission line 5 of the line unit 2 having the lower dielectric strength is provided. In this case, dielectric breakdown occurs in the aerial part, and no dielectric breakdown occurs in the aerial part on the aerial insulation main buses 7 and 8 side. Therefore, the insulation reliability of the air-insulated main buses 7 and 8 can be improved.

Regarding the arc horn provided on the suspension insulator or the long trunk insulator, the gap length between the overhead transmission line 5 side and the air-insulated main buses 7 and 8 side is provided with a difference of 10% or more. Therefore, when an arc horn operating condition such as a direct lightning strike to the steel structure 30 or the ground line 29 occurs, only the arc horn of the air insulator such as the suspension insulator 27 or the long trunk insulator 28 on the track side operates. Thus, the same effect as above can be obtained.

When the substation 1 is exposed to salt damage due to a typhoon or the like, all the insulators of the substation 1 are exposed to severe salt damage, and dielectric breakdown occurs at weak points. However, as described above, a difference of 10% or more is provided for the leakage length, and a difference of about 10% is provided for the dielectric strength. That is, the variation σ of the dielectric breakdown caused by salt damage is less than 5%, and by providing a dielectric strength difference of 10% or more of 2σ, the suspension insulator 27 and the long trunk insulator 28 having a short leakage length are necessarily provided.
Alternatively, the dielectric breakdown occurs on the line side of the line unit 2 constituted by the bushing 16, and the dielectric breakdown does not occur on the air-insulated main buses 7 and 8 side. Accordingly, the insulation reliability of the air-insulated main buses 7 and 8 can be increased.

The effect of flying objects by the wind and the effect of large birds flying near insulators such as suspension insulators and long trunk insulators can also be improved by providing a 10% or more difference in the insulation distance of the insulators. By reducing the influence on the insulated main buses 7 and 8 side,
The insulation reliability of the air-insulated main buses 7 and 8 can be increased.

The dielectric strength of the bushing 17 on the main bus side of the line unit 2 is set to be 10 times greater than that of the bushing 16 on the line side.
% Or more, but it is more effective to provide a difference of 15% or more of 3σ.

When the dielectric strength difference is increased to 50% or more, the size of the insulator such as the suspension insulator 31 and the long trunk insulator 32 on the main bus side or the size of the bushing 17 increases, and the cost of the insulator and the bushing increases. However, since the size of the steel structure 30 also increases, it is not advantageous from the viewpoint of economy.

Insulators and bushings for enhancing dielectric strength are as follows:
Suspension insulators 31 and long trunk insulators 32 for air-insulated main buses 7 and 8
Because it is limited to the bushing 17 on the main bus side of the insulator and the line unit 2 and the like, it is easy to strengthen the insulation, and it is significantly strengthened compared to the conventional air-insulated switchgear with many insulators and types. easy.

Therefore, the existing air insulated switchgear is replaced with the line unit 2 according to the present invention because the service life of the device has passed.
When upgrading to a compound gas insulated switchgear, etc., the number of air-insulated insulators will be significantly reduced, and the appearance will be improved.In addition, the time and effort for cleaning the insulators with reinforced insulation to prevent salt damage will be reduced. And maintenance costs can be reduced.

The air-insulated switchgear of the existing old substation is
By updating to a compound gas insulated switchgear such as the main line unit 2 when the life of the equipment is reached, the insulation level on the main bus side can be enhanced. That is, by applying the composite gas insulated switchgear such as the line unit 2 and the like, the insulation reliability on the main bus side of the substation can be significantly improved, and an effect more than simple equipment renewal can be obtained.

The existing old aerial insulated switchgear of the substation was updated to a composite gas insulated switchgear such as the line unit 2.
When changing the insulation strength of the aerial insulated main bus to 10% or more higher than before, it is difficult to stop the entire substation and perform the renewal work. It is possible to easily change the air-insulated main bus and renew the combined gas-insulated switchgear without stopping the operation.

That is, as a first stage, the two sets of air-insulated main buses 7 and 8 are alternately stopped, and the line unit 2, the transformer unit 3, the bus connection unit 4 and the like are updated one by one. Then, as a second stage, the two sets of the air-insulated main buses 7 and 8 are stopped one by one, and the suspension insulators 31 and the long trunk insulators 32 for supporting them are updated.

The renewal order is reversed, and the existing old aerial insulated main buses 107 and 108 (FIG. 13) are alternately stopped and replaced with two new aerial insulated main buses 7 and 8. Then, the two new air-insulated main buses 7 and 8 may be alternately stopped to update the line unit 2, the transformer unit 3, the bus connection unit 4 and the like one by one.

Alternatively, the existing old air-insulated main bus 10
7 and 108 are stopped to change to the new air-insulated main bus 7 or 8, and then the existing old air-insulated main bus or the changed new air-insulated main bus is stopped and the line unit 2 is transformed. The unit 3, the bus connection unit 4, and the like may be updated one by one, and the remaining old air-insulated main bus may be changed to a new air-insulated main bus.

In FIG. 2, the air-insulated main bus 7,
8 and the overhead transmission line 5 are supported by the suspension insulator 31 of FIG. 6 and the long trunk insulator 32 of FIG. 7, but the same applies to the case of being supported by a double suspension insulator, a V suspension insulator, or another shape of insulator. The effect of is obtained.

Although the line unit 2 in FIG. 3 is of a phase separation type in which the equipment for each phase is accommodated in one container, the equipment for one phase is accommodated in a plurality of containers. The same effect can be obtained by a three-phase package type in which the three-phase devices are collectively accommodated in one container.

Further, the components of the composite gas insulated switchgear such as the line unit 2 which are different from those shown in FIG. 3, for example, the lightning arrester 14 and the voltage transformer 15 on the line side are arranged at other parts in the container 2a. If the lightning arrester 14, the voltage transformer 15 and the like are not provided, and if the arrangement of the disconnector 9 on the main bus side is changed, the combined gas insulated switchgear may be used. The configuration of the middle insulating insulator is simplified, and the same effect can be obtained.

Although the composite gas insulated switchgear is shown in the case of the line unit 2 for the line, the same effect can be obtained by using the transformer unit 3 for the transformer or the bus connection unit 4 for the bus connection. Can be

Embodiment 2 Hereinafter, another embodiment of the present invention will be described with reference to FIGS. 8 is a single-line diagram of a single-bus substation, FIG. 9 is a side view of the substation, and FIG. 10 is a cross-sectional view of a bus connection unit for bus connection.
In FIG. 8, reference numeral 33 denotes a single bus type substation, and reference numeral 34 denotes a line unit which is a combined gas insulated switchgear for a line.
Reference numeral 35 denotes a transformer unit which is a composite gas insulated switchgear for a transformer, and reference numeral 36 denotes a bus connection unit which is a composite gas insulated switchgear for bus connection.

In FIG. 9 showing the side of the substation, reference numerals 37 and 38 denote main insulated buses, 41 and 42 denote aerial connection lines,
3 is a steel structure. The air-insulated main buses 37 and 38 are supported by the steel structure 43 via the suspension insulators 31, respectively, and are connected to the bushings 17 of the bus connection unit 36, which is a combined gas-insulated switchgear, respectively, by the air-connected wires 41 and 42. Connected by 29 is an overhead ground wire.

FIG. 10 shows a specific configuration of the bus connection unit 36 shown in FIG. 8. In FIG. 10, the bus connection unit 36 is filled with sulfur hexafluoride gas, which is a gas for electrical insulation. Container 36a and a control box 36b. In the container 36a, the disconnector 9 on the main bus side, the current transformer 1
0, one-point cutoff unit 11, operating device 11a for operating cutoff unit 11, grounding switch 13, lightning arrester 14, voltage transformer 1
5 are accommodated. Lightning arrester 14 and voltage transformer 15
Are juxtaposed on each end flange on both sides in the container 36a.

Further, in the container 36a, the air-insulating bushings 17 are disposed so as to be inclined such that the distance between the ends thereof is large so that the mutually required air-insulating distance can be secured. Have been. The bushing 17 of the bus connection unit 36 is the same as the bushing 17 of the line unit 2 shown in FIG. 3 on the main bus side, and its effective length is the effective length of the bushing 16 (FIG. 8) of the line unit 34 on the line side. It is at least 10% longer than the effective length a4 of the insulator tube 16a in FIG. 4). Bushing 1 of busbar connection unit 36
7 is the bushing 1 on the track side of the track unit 34.
6 (FIG. 8) (see the leakage length b4 of the insulator tube 16a in FIG. 4) by 10% or more. Therefore, the dielectric strength of the bus connection unit 36 is at least 10% stronger than the dielectric strength of the line unit 34 on the overhead transmission line 5 side.

The bushings 17 (FIG. 8) on the main bus side of the air-insulated main buses 37 and 38, the line unit 34, and the bushings 1 on the main bus side of the transformer unit 35 for the transformer.
7 (FIG. 8) similarly shows the overhead transmission line 5 of the track unit 34.
The dielectric strength of the bushing 16 (FIG. 8) on the side is strengthened by 10% or more. Other configurations are the same as those of the first embodiment shown in FIG. 3, and the corresponding components are denoted by the same reference numerals and description thereof is omitted.

Updating of the electric station 33 as described above is performed, for example, as follows. That is, the air-insulated main buses 37, 38
Is stopped, and the dielectric strength of the air-insulated main bus is enhanced by 10% or more. Next, the existing air-insulated switchgear or combined gas-insulated switchgear is updated to the combined gas-insulated switchgear of the present invention, such as the line unit 34, the transformer unit 35, and the bus connection unit 36. further,
The operation of the other of the air-insulated main buses 37 and 38 is stopped,
The dielectric strength of the aerial insulated main bus is enhanced by 10% or more.
The order of stop, change, update, and the like is not limited to the order described above, and can be changed as appropriate.

As described above, the dielectric strength of the bushing 17 of the bus connection unit 36, the air-insulated main buses 37 and 38, the bushing 17 of the line unit 34 on the main bus side, and the bushing 17 of the transformer unit 35 on the main bus side. Is greater than the dielectric strength of the line unit 34 on the side of the overhead transmission line 5 (FIG. 8).
By strengthening by 0% or more, the same effect as in the first embodiment can be obtained.

FIGS. 8 to 10 show examples of the single bus type substation 33. However, even in the case of other types of substations such as the 1.5CB type and the ring bus type, the dielectric strength on the main bus side is also shown. A similar effect can be obtained by strengthening. Of course, FIG.
Similar effects can be obtained even when the types and arrangements of the devices constituting the bus connection unit 36 are different from those shown in FIGS.

Embodiment 3 FIG. 11 is a cross-sectional view of a composite porcelain tube used for a bushing of a composite gas-insulated switchgear showing another embodiment of the present invention. FIG.
In the figure, reference numeral 44 denotes a composite insulator having an insulating tube 44a made of glass fiber reinforced synthetic resin, a cap portion 44b made of silicon rubber, which is a material having a higher elasticity than the insulating tube 44a, and metal flanges 44c and 44d. The cap portion 44b is formed by integrally forming a large number of caps projecting annularly from the cylindrical portion together with the cylindrical portion. A9 is the effective length of the composite insulator 44, b
9 is the leakage length.

In FIG. 11, the composite insulator 44 is lighter in weight and has higher mechanical strength than the ceramic insulator 17a shown in FIG. 5, for example, so that the composite insulator 44 has a large diameter even if the effective length is the same. Can be. By increasing the diameter, the electric field intensity in the air can be reduced, and the dielectric strength against lightning surge or the like can be improved. Further, since the cap portion 44b is made of silicon rubber having higher elasticity than the porcelain insulator tube or the insulating tube 44a made of glass fiber reinforced synthetic resin, the pitch of the cap portion of the cap portion can be made dense. If the pitch of the cap of the cap is made dense, the leak length can be lengthened even when the effective length is the same.

Therefore, even if the composite insulator 44 has the same effective length as the porcelain insulator, the composite insulator 44 can have a larger diameter, a smaller pitch of the cap of the cap portion, or a combination of both methods. The inside dielectric strength can be easily improved. Also, if such a composite insulator tube is employed and its effective length is slightly increased, the dielectric strength in the air can be easily improved by 10% or 15% or more.

If the composite insulator 44 is applied to the bushing 16 on the line side of the line unit 2 of FIG. 3 shown in the first embodiment, the size of the bushing 16 of the line unit 2 is reduced. The bushing 1 on the main bus side of the track unit 2
Applying to No. 7, the leakage length of the bushing 17 can be increased without increasing the size of the bushing 17 too much.

The composite insulator 44 is connected to the bushing 17 on the main bus side of the transformer unit 3 of FIG.
The same effect can be obtained by applying the present invention to the bushing 17 on the main bus side.
Even when the composite insulator 44 is applied to the bushing 18 on the transformer side of the transformer unit 3 in FIG. 1, the size of the bushing 18 is reduced similarly to the bushing 16 described above.

As described above, if the leakage length of the bushing is increased by using the composite insulator for the bushing, the salt damage resistance can be greatly improved. In addition, tracking due to salt damage can be prevented, and replacement for a long period of 15 years or more is not required, and there is no need to stop the aerial insulated main bus accompanying the replacement, which is convenient for operation of a substation.

Since the overhead transmission line 5 is easier to stop than the air-insulated main buses 7 and 8 of the substation 1, the composite insulator 44 serves as an insulator of the bushing 16 on the line side of the line unit 2.
Is adopted, even if it becomes necessary to replace the composite insulator pipe due to aging or the like, the operation of the overhead power transmission line 5 can be stopped and the composite insulator pipe 44 can be replaced.

If the composite insulator 44 is applied to the bushing 16 on the line side of the line unit 2, the line unit 2
Since the size of the bushing 16 becomes smaller, when a substation is newly installed, the size of the anchoring tower 26 (see FIG. 2) on the overhead transmission line 5 and the like can be reduced, and the substation can be constructed economically.

In the case where the air-insulated switchgear of the existing substation is replaced with a new compound gas-insulated switchgear, if the compound gas-insulated switchgear having a bushing using the composite insulator of the present invention is applied, It is not necessary to change the existing steel structure and the dimension between phases of the aerial insulated main buses, so that the existing substation can be renewed and the insulation reliability can be improved economically.

Further, when replacing an old compound gas insulated switchgear of a substation with a new compound gas insulated switchgear,
By updating to a composite gas insulated switchgear having a bushing using the composite insulator of the present invention, the length of the bushing does not need to be increased, and the length of the suspension insulator or the long trunk insulator of the air-insulated main bus can be increased. There is also an advantage that the dielectric strength of the aerial insulation device can be easily enhanced simply by doing so.

The material of the cap portion 44b of the composite insulator 44 is not limited to silicon rubber, and other synthetic resins and the like can be used as long as the object of the present invention is not impaired.

The same effects can be obtained not only in substations but also in power stations, switchyards and other electric stations. Note that the line unit 2, the transformer unit 3, the bus connection unit 4, the line unit 34, the transformer unit 35, and the bus connection unit 36 described in each of the above embodiments are combined gas-insulated switchgears according to the present invention. , Overhead transmission line 5,
The transformer 6 is the electric equipment in the present invention.

[0086]

Since the present invention is constructed as described above, it has the following effects.

The combined gas insulated switchgear of the present invention has first and second air-insulated bushes, is connected to the air-insulated main bus via the first bushing, and has the second bushing. In the compound gas insulated switchgear connected to the electrical equipment via the, the dielectric strength of the first bushing is 10% or more higher than the dielectric strength of the second bushing, Since the variation σ of the dielectric breakdown in the air is less than 5%, by providing an insulation level difference of 10% or more of 2σ, the dielectric breakdown always occurs in the aerial part on the second bushing side, which has the lower dielectric strength. Insulation does not occur in the aerial part on the first bushing side. Therefore, the insulation reliability of the first bushing side is improved, and a highly reliable composite gas insulated switchgear can be obtained.

The composite gas insulated switchgear of the present invention has an insulating cylinder and a cap made of an organic material, and has a cap made of an organic material for a cap having a higher elasticity than the organic material. Since the part is characterized by being a composite insulator fitted to the outer periphery of the insulating cylinder, the effective length is the same because the composite insulator is lighter and has higher mechanical strength than the porcelain insulator. Even if it is, it can be made a large diameter. Increasing the diameter decreases the electric field intensity in the air, so that the dielectric strength against lightning surge and the like can be improved. In addition, since the cap portion is formed of a cap material having a high elasticity, the pitch of the cap portions of the cap portion can be made dense. If the pitch of the cap of the cap is made dense, the leakage length can be lengthened even if the effective length is the same. Therefore, compared to porcelain porcelain tubes, even in the case of the same effective length, the insulation strength in the air can be easily increased by increasing the diameter, reducing the pitch of the cap of the cap portion, or using both methods together. Can be improved. Therefore, if the composite insulator is applied to the first bushing or the second bushing, the size can be reduced.

Further, an electric station having the composite gas insulated switchgear of the present invention is provided with an air-insulated main bus, electric equipment, and a composite gas insulated switchgear. Is an electrical substation having first and second air-insulated bushings, connected to the air-insulated main bus via the first bushing, and connected to electrical equipment via the second bushing. Wherein the dielectric strength of the air-insulated main bus and the first bushing is at least 10% higher than the electrical strength of the electrical equipment and the second bushing. Since the variation σ is less than 5%, by providing an insulation level difference of 10% or more of 2σ, insulation breakdown occurs in the electric equipment having the lower dielectric strength or in the air part on the second bushing side, so that the air insulation Busbar In addition, dielectric breakdown does not occur in the aerial part on the first bushing side. Therefore, the insulation reliability of the aerial insulated main bus and the first bushing side is improved, and an electric station with a high insulation reliability can be obtained because the aerial insulated main bus is hard to stop.

Further, in the method of updating an electric substation according to the present invention, the existing air-insulated main bus has a dielectric strength of 10 times higher than the conventional one.
Main bus change process to change to air insulated main bus higher than
3. A switching device update process for removing an existing air-insulated switchgear and replacing it with a composite gas-insulated switchgear according to claim 1 or 2, and a changed air-insulated main bus and a renewed composite gas 3. A combined gas insulated switchgear according to claim 1 or 2, wherein a connection step for connecting to the insulated switchgear is provided, so that the insulated main bus is changed to an insulated main bus having a dielectric strength of at least 10% higher than the conventional one. By renewing the device, insulation breakdown occurs in the electric equipment having the lower dielectric strength or in the aerial part on the second bushing side, and the dielectric breakdown does not occur in the aerial insulated main bus and the aerial part on the first bushing side. Therefore, the insulation reliability of the air-insulated main bus and the first bushing side can be improved, and a highly reliable electric station where the air-insulated main bus is hard to stop can be realized.

In the method for updating an electric substation according to the present invention, the existing air-insulated main bus is a double bus, and the existing air-insulated switchgear is provided with a plurality of switches, and the main bus is changed. The process is to alternately stop the operation of the existing aerial insulated main bus and change to an aerial insulated main bus whose dielectric strength is 10% or more higher than before. It is characterized in that the operation of the insulated main bus is alternately stopped and the aerial insulated switchgear is replaced with a composite gas insulated switchgear. By changing the air-insulated main bus to 10% or more, stopping the operation of the existing or changed air-insulated main bus alternately, and replacing the existing air-insulated switchgear with a composite gas-insulated switchgear. , Avoiding a total stoppage, New can be carried out.

[Brief description of the drawings]

FIG. 1 is a single-line diagram of a substation to which a combined gas-insulated switchgear according to an embodiment of the present invention is applied.

FIG. 2 is a side view of the substation of FIG.

FIG. 3 is a sectional view of a line unit of the substation of FIG.

4 is a sectional view of a porcelain tube of a bushing on the track side of the track unit of FIG. 3;

5 is a sectional view of a porcelain tube of a bushing on a main bus side of the line unit of FIG. 3;

FIG. 6 is a side view of the suspension insulator of FIG. 2;

FIG. 7 is a side view of the long trunk insulator of FIG. 2;

FIG. 8 is a single-line diagram of a single-bus type substation according to another embodiment of the present invention.

9 is a side view of the substation of FIG.

FIG. 10 is a sectional view of a bus connection unit of the substation of FIG.

FIG. 11 is a sectional view of a composite insulator tube used for a bushing of a composite gas-insulated switchgear according to another embodiment of the present invention.

FIG. 12 is a single-line diagram of a substation to which a conventional combined gas-insulated switchgear is applied.

FIG. 13 is a side view of a conventional substation.

FIG. 14 is a cross-sectional view of a conventional line unit.

FIG. 15 is a sectional view of a bushing porcelain tube on the line side of a conventional line unit.

FIG. 16 is a side view of a conventional suspension insulator.

FIG. 17 is a side view of a conventional long trunk insulator.

FIG. 18 is a side view of a conventional all-gas insulated switchgear.

[Description of Signs] 1 Substation, 2 Line Unit, 3 Transformer Unit,
4 Busbar connection unit, 5 overhead transmission line, 6 transformer,
7,8 Aerial insulated main bus, 16 bushing on track side,
17 bushing on main bus side, 18 bushing on transformer side, 19, 20, 21, 22, 23 aerial connection line, 2
6 Termination tower, 27, 31 suspension insulator, 28, 32 long trunk insulator, 30 steel structure, 33 substation, 34 line unit, 35 transformer unit, 36 bus connection unit,
37,38 Air-insulated main bus, 39,40,41,42
Aerial connection line, 44 Composite insulator, 44a Insulation tube, 44
b Kasabe.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H02B 13/04 L (72) Inventor Hitoshi Sadakuni 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsuishi Electric F term in the company (reference) 5G017 AA13 AA32 BB10 JJ01

Claims (5)

[Claims] An air-insulated first and second bushing is connected to an air-insulated main bus via the first bushing and to electrical equipment via the second bushing. Wherein the dielectric strength of the first bushing is at least 10% higher than the dielectric strength of the second bushing. 2. The insulator tube of at least one of the first and second bushings has an insulating tube made of an organic material and a cap portion formed of an organic material for a cap portion having a higher elasticity than the organic material. The composite gas insulated switchgear according to claim 1, wherein the portion is a composite insulator tube fitted to an outer peripheral portion of the insulating cylinder. 3. An air-insulated main bus, electrical equipment, and a composite gas-insulated switchgear, wherein the composite gas-insulated switchgear has first and second air-insulated bushings. In an electric station connected to the aerial insulated main bus via the first bushing and connected to the electrical equipment via the second bushing, the aerial insulated main bus and the An electric substation, wherein a dielectric strength of one bushing is higher than a dielectric strength of the electric equipment and the second bushing by 10% or more. 4. A method for updating an electric substation, comprising the following steps. A. The insulation strength of the existing aerial insulated main bus is 10 times higher than before.
Main bus change process to change to aerial insulated main bus by at least%. I. 3. A switching device updating step of removing an existing air-insulated switching device and replacing it with the combined gas-insulated switching device according to claim 1 or 2. C. A connection step of connecting the changed air-insulated main bus and the updated combined gas-insulated switchgear; 5. The existing air-insulated main bus is a double bus, a plurality of existing air-insulated switchgears are installed, and the main bus changing step is to operate the existing air-insulated main bus. Are alternately stopped to change to an air-insulated main bus whose dielectric strength is 10% or more higher than before, and the switchgear updating process alternately stops the operation of the existing or changed air-insulated main bus. The method according to claim 4, wherein the medium-insulated switchgear is replaced with a composite gas-insulated switchgear.