JP3532252B2 - Gas insulated switchgear - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to gas insulated switchgear .

[0002]

2. Description of the Related Art In a gas-insulated switchgear, an insulating gas is enclosed in a hermetically sealed container, the insulating gas is maintained at a predetermined pressure, and good insulating performance is exhibited by the characteristics of the insulating gas. I am maintaining.

An example of a conventional gas-insulated switchgear housing a gas-insulated circuit breaker (hereinafter referred to as GCB) is shown in the right side view of FIG. In FIG. 6, an L-shaped bushing 2 is attached to the rear surface of the L-shaped partition wall 1a provided on the upper rear portion of a box body 31 whose outer periphery is surrounded by a metal plate. At the lower end of the bushing 2, a high-pressure cross-linked polyethylene cable (hereinafter, simply referred to as a cable) 4 that is raised from a pit provided on the floor where the gas-insulated switchgear is installed is connected. The through-type current transformer 3 fixed to the lower rear end of the box body 31 is loosely fitted.

A rear end of the disconnector 6A is connected to the front end of the bushing 2 via a connecting conductor 5. This disconnector 6
The front end of A is connected to the front end of the power receiving chamber 11A surrounded by the wall 1a and the rear terminal of an insulating spacer 7A for gas-distributing the front GCB via a connecting conductor 5.
The front terminal (not shown) of A is connected to the lower pole of the GCB 8 housed in front of the insulating spacer 7A. Reference numeral 9 is a voltage detecting insulator, the lower end of which is connected to the conductor 5 which connects the bushing 2 and the disconnector 6A.

Further, the disconnector 6 is provided on the upper pole of the GCB chamber 11B via an insulating spacer 7B having the same shape as the insulating spacer 7A.
A disconnector 6 of the same shape as this disconnector 6A housed in the upper part of A
The front end of B is connected. At the rear end of the disconnector 6B, the gas-insulated bushing 10 that is provided through the ceiling of the box 31 is provided.
And is connected to the lower end of the cable. The upper terminal of the gas insulating bushing 10 is connected to an electric device inside a box body (not shown) adjacent to the box body 1 through a gas insulating bushing penetrating the box body.

The box 31 includes a power receiving room 11A and a GCB room 11
Gas is divided into B and the bus room 11C, and sulfur hexafluoride gas (hereinafter referred to as SF ₆ gas) 12 is sealed in each room. On the other hand, except the power receiving chamber 11A, the GCB chamber 11B, and the busbar chamber 11C, they are air-insulated at atmospheric pressure.

The pressure of the SF ₆ gas is a low pressure of 2 kgf / cm ² or less in order to make it a non-pressure container which is not legally regulated during transportation because the vessels of the power receiving chamber 11A and the busbar chamber 11C are rectangular. It is under pressure. In addition, the GCB chamber 11B is a cylindrical pressure vessel with 4-5 kgf /
High pressure of cm ² is used. The lower part of the GCB chamber 11B is an air insulation chamber of an operation mechanism chamber 8a for operating the GCB housed in the GCB chamber 8.

Here, the insulating spacers 7A and 7B are GC
Withstanding and maintaining the pressure difference between the B chamber 11B, the power receiving chamber 11A, and the bus chamber 11C, the charging parts such as the connecting conductors are connected to the ground potential of the box or the like and between the charging parts, that is, Maintains insulation properties between phases.

Insulating spacer 7 used for such an application
As disclosed in Japanese Utility Model Publication No. 2-10724, A and 7B have a thick insulating layer in order to withstand the pressure difference between adjacent gas chambers and insulation on the side where the pressure of SF ₆ gas is low. By increasing the creepage distance of the layer, the insulation characteristics are maintained at a predetermined value.

[0010]

In the spacers 7A and 7B penetrating in such a place, since the GCB 11B has a cylindrical shape and the three-phase blocking portions are arranged in a triangle in a plan view not shown, The lead-out portion also has a triangular arrangement in a rear view (not shown), and the flange portion has a three-phase disc shape.

Therefore, in order to maintain the pressure difference between the gas chambers, in the spacers 7A and 7B, the thickness of the insulating layer including the mounting portion of the flange is increased so as to withstand the mechanical bending stress caused by the pressure difference. Must be considered.

On the low pressure side of the gas chamber, SF
_Since the dielectric strength of the ₆ gas shows an insulating property proportional to the density of the SF ₆ gas, the dielectric strength is lower than that of the high pressure gas chamber side.
For this reason, the creepage distance must be increased.

Further, since the insulating spacers 7A and 7B are arranged in a three-phase triangular shape, the arrangement of devices in the power receiving chamber 11A and the busbar chamber 10C is restricted, and the arrangement becomes complicated such as bending the connection conductor 5. Thus, insulating spacers 7A, 7B with outer diameter large in size, the arrangement of the equipment inside the box body is restricted, the storage efficiency is outside shape is large in size of the gas insulated switchgear reduced.

Therefore, the object of the present invention is to house the inside.
Gas that can increase the degree of freedom in the arrangement of electrical equipment and conductors
It is to obtain the switch switch gear .

[0015]

[0016]

In the gas-insulated switchgear according to the first and second aspects of the invention, between the first and second electric equipment chambers in which the pressure of the enclosed insulating gas is different, It is characterized in that an insulating gas having a pressure intermediate between the pressures of these electric device chambers is filled and a conductor chamber for connecting the electric devices of the first and second electric device chambers by a conductor is provided adjacently.

Further, in the gas insulated switchgear according to the third and fourth aspects of the present invention, the gas pressure between the circuit breaker and the electric equipment room is intermediate between the gas pressure of the circuit breaker and the gas pressure of the electric equipment room. A main circuit conductor chamber is provided adjacently, one side of the conductor arranged in the main circuit conductor chamber is connected to a circuit breaker via a first insulating spacer, and the other side of the conductor is connected via a second insulating spacer. It is characterized by being connected to the electrical equipment room.

[0018]

[0019]

[0020]

According to the first and second aspects of the present invention, the conductor connecting portions of the conductor chambers connected to the electric devices of the first and second electric device chambers are provided with an intermediate portion enclosed in the conductor chamber. The insulating gas at pressure improves mechanical characteristics and withstand voltage characteristics.

Further, in the inventions according to claims 3 and 4 , the first insulating spacer and the second insulating spacer are made to withstand a withstand voltage by the intermediate pressure insulating gas filled in the main circuit conductor chamber. The characteristics are improved, and the degree of freedom in the position of the electric device and the conductor housed in the electric device chamber is improved by the conductor and the insulating spacer arranged in the main circuit conductor chamber.

[0022]

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the same parts as those of FIG. 6 shown in the related art are designated by the same reference numerals and the description thereof will be omitted.

[0024] FIG. 1 shows a structure of insulation spacers viewed gas insulated switchgear that is mounted from the right side. Figure 1
6, an L-shaped bushing 2 is attached to the rear surface of the partition wall 1a inside the box body 1 as in FIG. 6 shown in the related art, and this gas insulated switchgear is shown at the rear portion of the box body 1. The power is received by the cable 4 penetrating the through-type current transformer 3.

In the power receiving room 11A surrounded by the partition wall 1a, the disconnecting switch 6A and the voltage detecting insulator 9 are housed as in the case of FIG.
An insulating spacer 13A that penetrates the front end of 11A is connected to the lower chamber of a cylindrical pressure relaxation chamber 11D that is vertically adjacent to the power receiving chamber 11A. Further, an insulating spacer 14A which is circular in the right side view of FIG. 1 is provided at the front end of the pressure relaxation chamber 11D, and the insulating spacer 14A and the insulating spacer 13A are connected by an insulating conductor 15.

On the back side of the upper part of the GCB chamber 11B, the insulating spacer 14B is also penetrated to the front end of the pressure relaxation chamber 11D, like the lower side. The rear end of this insulating spacer 14B is a bus room.
It is connected to the front end of the disconnector 6B via an insulating spacer 13B penetrating the front end of 11C and a connecting conductor 5 whose front end is connected to this insulating spacer 13B. The rear end of the disconnector 6B is connected to the lower end of an insulating bushing 10 penetrating the ceiling above the disconnector 6B via a connecting conductor 5. In addition, the power receiving room 11A, the gas circuit breaker room 11B, the bus room 11
SF ₆ gas 12 is sealed in the pressure relaxation chamber 11D of C.

The pressure of SF ₆ gas in each of these chambers is about 0.3 kgf / because the power receiving chamber 11A and the busbar chamber 11C are rectangular containers.
Low pressure of cm ² and 5 kgf / cm ^{2 for} GCB chamber 11B
Has become a high pressure.

On the other hand, the pressure in the pressure relaxation chamber 11D is
The pressure in the CB room 11B is set to 4 kgf / cm ² which is between the power receiving room 11A and the bus room 11C in the rear. Therefore, the pressure applied to the insulating spacer 14A from the front of the insulating spacer 14A is about 1 kgf / cm ² , and the pressure applied to the front surfaces of the insulating spacers 13A and 13B is about 3.7 kgf / cm ² .

In addition, the insulating spacer 14 on the side of the GCB chamber 11B
Although A and 14B are three-phase insulating spacers similar to FIG. 6 shown in the prior art, the insulating spacers 13A and 13B on the power receiving chamber 11A side and the busbar chamber 11C side are single-phase insulating spacers described later in FIG. The insulating spacers are arranged in an inverted triangle.

In the insulating spacer thus constructed, the pressure difference between the front and rear gas chambers of each of the insulating spacers 13A, 13B, 14A, 14B is reduced, and this pressure difference reduces the pressure received from one side. Therefore, the thickness of the insulating layer can be reduced, and the weight can be reduced.

The dielectric strength depends on the gas density which is proportional to the pressure of SF ₆ gas.
Since the difference in the density of SF ₆ gas on both sides of 13B, 14A and 14B is reduced, it is not necessary to extremely increase the creepage distance on the side where the density of SF ₆ gas is low. Therefore, the left and right creepage distances that protrude into the interiors of the respective chambers with the mounting flanges between the respective gas chambers being substantially the same, and the insulating spacer as a whole can be made smaller.

Further, in the pressure relaxation chamber 11D, a connection conductor is formed.
Since the positions of the 15 phases can be converted as shown in FIG. 1, the positions of the conductors of the respective phases can be switched according to the arrangement of the devices in the power receiving room 11A and the bus room 11C.

For example, in FIG. 1, the arrangement of the phases of the conductors in the inverted triangular arrangement on the side of the GCB chamber 11 is changed so that the power receiving chamber 11A and the busbar chamber 11C are changed.
It is arranged in an upward triangle on the side. Where the power receiving room
11A and the insulating spacer 13C at the bottom of the bus room 11C are shown in FIG.
As will be described later, it is used as an insulating support in which the central conductor is not buried in the right side from the intermediate portion, and the rear end of the connection conductor 15 is supported and fixed.

Therefore, in addition to the three insulating spacers 13A, an insulating spacer 13C as an insulating support, which will be described in detail later with reference to FIG. 5, is provided through the disk-shaped flange. In the right side view, it is arranged in a vertical and horizontal rectangular shape. The insulating spacers 13A and 13B may be, for example, a right triangle or an isosceles triangle according to the arrangement of the terminals of the device on the power receiving room side, and can be arbitrarily selected.

Next, FIG. 2 is an enlarged detailed view of the single-phase insulating spacers 13A and 13B shown in FIG. This insulating spacer is composed of an insulating layer 17 made of epoxy resin around the center conductor 16.
Is formed coaxially by casting, an annular flange portion 17a is formed on the outer periphery of the substantially central portion, and a flange 18 provided on the gas chamber side is formed.
It is fixed to the outer surface of the through the O-ring 18a while maintaining airtightness.

The outer periphery of both sides of the flange 17a has a cross section of approximately L.
V-shaped grooves 19 A, 19 B are formed, and conductive paint is applied to the inner surfaces of the grooves 19 A, 19 B and the surface of the flange portion 17 a to form a ground layer 20, and the flange 17 a on the ground side is formed. The electric field is relaxed on both sides. Where the center conductor
A shaft core portion 16a having a diameter φ1 which is larger than the small diameter portion 16D is formed between the small diameter portions 16D at both ends where 16 is in contact with the central portion of the insulating layer 17.

Further, at the end of the center conductor 16, projections 16B and 16C having a diameter of φ2 and a diameter of φ3 are formed by chamfering the stepped portion on the outer periphery, for the purpose of electric field relaxation, with the stepped portion having a curved surface. ing. In the insulating spacer 13C described above with reference to FIG. 1, the central conductor 16 shown in FIG. 2 is divided into two parts at the center, and as shown in FIG. 5, the short central conductor 16A is embedded only on the left side and formed by casting. There is.

In the insulating spacer thus constructed, the insulating layer end portion 17b having a high electric field strength can suppress the progress of the streamer which causes the dielectric breakdown because the electric field is relaxed by the shaft core portion 16a.

That is, in the insulating spacer as shown in FIG. 2, the intersection of the both ends of the insulating layer 17 and the outer periphery of the small diameter portion 16D is the highest electric field strength due to the so-called triple junction. Is alleviated. Further, the gas-side shaft core portion 16a further suppresses an increase in electric field strength.

Further, the diameter φ1 of the shaft core portion 16a and the protruding portion 16
By making the diameter φ2 of B the same, the portion of the surface of the insulating layer 17b having the maximum electric field strength is separated from the central conductor 16, and the component forming the maximum electric field strength is a normal direction component ≧ a tangential direction component. Become. As a result, the dielectric breakdown becomes a gas space, and the streamer on the surface of the insulating layer 17 can be prevented from developing.

Therefore, the creeping surface of the insulating layer 17 exhibits unstable dielectric strength in the air due to surface irregularities, imbalance of surface resistivity, adhesion of foreign matter, etc.
It has a stable dielectric strength that depends on the gas density.

The diameter φ2 of the protruding portion 16B is increased,
If φ2> φ1, the component in the normal direction becomes smaller than the component in the tangential direction, and the dielectric strength varies. Therefore, the creepage distance of the insulating layer 17 must be increased, and as a result, the outer shape of the insulating spacer becomes large.

In order to connect the connecting conductors to both ends of the insulating bushing, the projection 16C is formed, and the outer diameter φ3 of the projection 16C can be increased and a large radius of curvature can be formed. It can be miniaturized.

[0044] Thus, by using a miniaturized insulative spacer, relative to the disc-shaped flange 21 of the gas chamber, as shown in FIG. 3, the vertical and the insulating spacers 13 A of the three phases
Can be placed in any direction.

Next, another embodiment of the gas-insulated switchgear employing this insulating spacer is shown in FIG. Note that FIG.
In, the GCB chamber 11 B side of the pressure relief chamber 11D, although using a connection spacer 14A of three-phase, the receiving chamber 11A and bus chamber 11C is an insulating spacer 13A of the single-phase as shown in FIG. 3 It is attached in a row horizontally.

For this reason, the positions of the three-phase connecting conductors 24 inside the pressure relaxation chamber 11D are changed with respect to the disconnecting devices 6A and 6B in which the disconnecting rods of each phase are arranged laterally in a row. By arranging them in a line horizontally as shown and connecting them to the insulating spacer 13A, it is possible to connect the devices on a straight line.

Therefore, the insulating spacer 13A and the disconnector 6
The distance between A and 6B can be shortened, and the overall outer diameter can be reduced.

Further, by adopting the single-phase insulating spacer 13A, the area of the flange of each insulating spacer is reduced, and the reduction of this area also reduces the pressure applied to the entire area. Therefore, the thickness of the insulating layer of the flange, etc. It is also possible to shorten the molding cycle, reduce strain and reduce weight.

In the above embodiment, the insulating spacer incorporated in the switchgear has been described. However, the main circuit terminals at both ends of an electric device such as an instrument transformer are integrally cast-molded with an insulating resin to form a high-voltage electric device. The same can be applied to the connecting portion.

That is, a large diameter portion corresponding to the shaft core portion 16a of the insulating bushing shown in FIG. 2 is formed on the inside of the insulating layer of the conductor, and the protrusion having the same diameter as this large diameter portion shown in FIG. Department
By forming a large-diameter portion corresponding to 16B and 16C on the gas chamber side and removing the right side from the left side of the flange 17a of the insulating spacer shown in FIG. 5, the electric field due to the triple junction described above is relaxed. In addition, the component of the maximum electric field strength on the creeping surface of the insulating layer can be set to the normal direction component ≧ the tangential direction component, the dielectric strength can be stabilized, and the connection portion of the high-voltage electric device can be downsized.

[0051]

[0052]

Effects of the Invention According to the invention described in claims 1 and 2, a first pressure of the encapsulated insulation gas is different between the second electrical device chamber, the pressure of these electrical equipment room By providing a conductor chamber in which an insulating gas having an intermediate pressure is filled, and arranging a conductor for connecting the electric devices in the first and second electric device chambers to the conductor chamber, the first and second electric devices are provided. For the connection part of the conductor of the conductor room that connects the electrical equipment of the room, the withstand voltage characteristics were improved by the insulating gas of the intermediate pressure sealed in the conductor room. It is possible to obtain a gas-insulated switchgear capable of increasing the degree of freedom of arrangement.

According to the third and fourth aspects of the present invention, the gas main circuit conductor having an intermediate pressure between the gas pressure of the circuit breaker and the gas pressure of the electric equipment room is provided between the circuit breaker and the electric equipment room. A chamber adjacent to the main circuit conductor chamber, one side of the conductor is connected to the circuit breaker through the first insulating spacer, and the other side of the conductor is connected through the second insulating spacer to the electrical equipment chamber. By connecting the first insulating spacer and the second insulating spacer with each other, the withstand voltage characteristics of the first insulating spacer and the second insulating spacer are improved by the insulating gas of the intermediate pressure sealed in the main circuit conductor chamber, Since the degree of freedom of position is improved with respect to the conductor by the conductor and the insulating spacer arranged in the main circuit conductor chamber, it is possible to increase the degree of freedom in the arrangement of the electrical equipment and the conductor housed inside. You can get gears.

[0054]

[Brief description of drawings]

[1] As an example of a state where insulation spacer is incorporated in the gas insulated switchgear, a right side view showing an embodiment of a gas insulated switchgear of the invention described in claim 1, 2, 3 and claim 4 .

Figure 2 is a partial half cross-sectional view showing an embodiment of insulation spacer.

FIG. 3 shows another embodiment of the insulation spacer.

FIG. 4 is a right side view showing another embodiment of the gas-insulated switchgear of the invention described in claims 1, 2, 3 and 4 .

5 is an enlarged detailed view of an insulating spacer 13C shown in FIG.

FIG. 6 is a right side view showing an example of a conventional gas insulated switchgear.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Box body, 2 ... Bushing, 3 ... Current transformer, 4 ... High voltage bridge | crosslinking polyethylene cable 5 ... Connection conductor, 6A, 6B ... Disconnector, 8 ... Gas insulation circuit breaker, 9 ... Electric insulation insulator, 10 ... Gas insulation Bushing, 11A ... power receiving room, 11B ... gas circuit breaker room, 11
C ... Bus room, 11D ... Pressure relaxation room, 12 ... Insulating gas, 13A,
13B, 13C, 14A, 14B ... Insulating spacer, 15, 24 ... Connection conductor, 16 ... Center conductor, 16a ... Large diameter portion, 16B ... Projection portion, 17
... Insulating layer, 18, 21 ... Flange, 19A, 19B ... Groove, 20 ... Ground layer.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Sakaguchi No. 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu factory, Toshiba Corporation (56) Bibliographic references Sho 54-1187 (JP, U) (58) Field (Int.Cl. ⁷ , DB name) H02B 13/02 H02G 5/08 361

Claims (4)

(57) [Claims] 1. A first electric equipment room in which an insulating gas is filled, a second electric equipment room having a gas pressure different from a gas pressure of the first electric equipment room, and a second electric equipment room. A gas in the first and second electric equipment chambers is provided adjacent to the first electric equipment chamber, and a conductor is provided to connect the electric equipments housed in the first and second electric equipment chambers. A gas-insulated switchgear consisting of a conductor chamber filled with insulating gas at an intermediate pressure. 2. The pressure of the insulating gas in the first electric equipment room is set to 5
kgf / cm ² , the pressure of the insulating gas in the second electrical equipment room is 0.3 kg
f / cm ² , pressure of insulating gas in conductor chamber is 0.3kgf / cm ² or more 4
The gas-insulated switchgear according to claim 1 , wherein the gas-insulated switchgear is less than kgf / cm ² . 3. A circuit breaker filled with an insulating gas, an electric equipment room having a gas pressure different from the gas pressure of the circuit breaker, and a circuit breaker provided adjacent to the electric equipment room and the circuit breaker. A main circuit conductor chamber in which a first insulating spacer to be connected and a second insulating spacer to be connected to the electric equipment chamber are penetratingly provided, and an insulating gas is filled at an intermediate pressure between gas pressures of the circuit breaker and the electric equipment chamber. Gas insulated switchgear consisting of. 4. The first insulating spacer is a three-phase collective type,
The gas-insulated switchgear according to claim 3 , wherein the second insulating spacer is of a phase-separated type.