JPS62144510A - Gas insulated electric equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to gas insulated electrical equipment, and more particularly to a gas insulated electrical equipment provided with a conductor penetrating the side wall of a box filled with insulating gas.

B0 Summary of the Invention In a gas-insulated electric device, a cylindrical insulator filled with gas is provided on at least one side of a side wall of a box body, and gap dimensions between a conductor insertion hole provided in the side wall of the box body and the conductor. g,
The length of the inner wall of the cylindrical insulator (the length in the axial direction facing the conductor) is Q, and the inner diameter of the conductor insertion hole is φ1. By setting the inner diameter of the insulator to φ2 and optimizing the relationship between these dimensions, it is possible to downsize the cylindrical insulator and, by extension, downsize gas-insulated electrical equipment, while reducing the dielectric strength voltage. This was planned without any fuss.

C1 Conventional technology A gas switchgear is an example of gas-insulated electrical equipment, in which main circuit equipment such as circuit breakers and new line switches, and busbars connected to these are housed in a metal box. A grounded configuration is adopted. In this case, in order to downsize the equipment housed within the box and to ensure insulation, the box is filled with an insulating gas such as SF8 gas or a mixed gas of SF6 gas and air.

In the gas-insulated switchgear mentioned above, in order to connect the equipment housed in the box with external equipment, a conductor is required to penetrate the side wall of the box, and the conductor and the side wall must be insulated and separated as well as supported. Requires. There are various types of insulating support for the conductor that penetrates the side wall of the box, but the optimal configuration is based on the insulation characteristics of the gas, that is, the one that fully brings out the effect of miniaturization, which is a feature of gas insulation. It is strongly desired to find a structure.

Now, conventional gas insulated electrical equipment will be explained with reference to the schematic diagram shown in FIG. It is divided into chamber 15. Reference numeral 11 denotes a cylindrical insulator (bushing) that penetrates the box side wall 2 and is fixed to the box side wall 2, and an internal fixed conductor 31 is provided passing through the axial center of the bushing. The bus bar chamber 15 is filled with an insulating gas such as SP or gas at atmospheric pressure or a pressure higher than atmospheric pressure (0.10 to 0.2 MPa). 18 is a drawer-type breaker, and an internal fixed conductor 31
It has an external conductor 19 that comes into contact with and separates from the protruding tip 31a of the external conductor 19, and the contact and separation part is formed as a disconnection part 9. Therefore, when the drawer-type breaker 18 is carried into the breaker chamber IO, its outer conductor 19 and the protruding tip 31a of the internal fixed conductor 31 are connected to establish electrical continuity.

Therefore, the 24th part of the cylindrical insulator (bushing) 11 was
This will be explained based on the diagram. That is, in FIG. 24,
A through hole 4 is bored in a side wall 2 of a box body of an electrical device l filled with an insulating gas, and a cylindrical insulator 11 is provided protruding from the outside of the through hole 4. The cylindrical insulator 11 has a flange portion 11a and a boss portion 11.
b, and is hermetically coupled to the eight-body side wall 2 with bolts 20 with a sealing material 23 such as an O-ring interposed at the flange portion Lla. On the other hand, an internal fixed conductor 31 is provided in this cylindrical insulator 11 with a sealing material 22 such as an O-ring interposed therebetween, and passes through the cylindrical insulator 11 in an airtight manner.

FIG. 23 shows a model of the cylindrical insulator 11 shown in FIG. 24. Then, the insulation voltage characteristics of the modeled cylindrical insulator 11 shown in FIG. 23 were investigated. FIG. 22 shows the results in a graph. This will be explained below, and the meanings of the symbols used in FIGS. 23 and 24 are as shown in the table below.

L Length of the outer wall of the cylindrical insulator projecting outward from the side wall of the two-piece assembly φ,: Inner diameter of the conductor insertion hole (mm) φ,: Inner diameter of the cylindrical insulator (+nn+) φ3: Cylindrical insulation Outer diameter of the object (mm) a: Gap dimension (mm) between the inner periphery of the conductor insertion hole and the cylindrical insulator. The boss portion 11b of the shaped insulator 11 is
There is no adverse effect on the creeping electric strength characteristics of the cylindrical insulator 11, and in the configurations shown in FIGS. 23 and 24, φ1° to φ3. φ
3. It has been confirmed in various shapes and sizes that if a and L are the same, both have the same withstand voltage characteristics, and the results will be omitted here.

The experimental results shown in FIG. 22 are as follows for the cylindrical insulator 11 shown in FIG. The measurement was carried out by varying L (aluminum round rod: 30 mm) and in pure SF gas at a pressure similar to atmospheric pressure (approximately 0.1 MPa).

The results are shown in Figure 22.As can be seen from the figure, the flash fault voltage characteristics of positive and negative polarities are reversed when the L dimension is around 38 mm, and by increasing L beyond this, the positive polarity resistance can be improved. This shows that although the voltage characteristics increase, the negative polarity withstand voltage characteristics actually decrease. The reason for this is thought to be that the cylindrical insulator 11 penetrates the box side wall 2.

Furthermore, it is conceivable that the minute gap a between the internal conductor 31 and the conductor insertion hole 4 is also a cause.

D1 Problem to be solved by the invention In the end, as long as the cylindrical insulator 11 penetrates the box side wall 2, L can be increased to increase the creepage distance between the internal fixed conductor 31 and the box side wall 2. It was found that even if we tried to solve the problem of withstand voltage characteristics, the withstand voltage characteristics did not improve.

That is, if L is increased to increase the creepage, the positive withstand voltage characteristics will improve, but the negative withstand voltage characteristics will conversely deteriorate.

If L is further increased, the creeping withstand voltage characteristics will be improved, but in practical terms, the electrical equipment housing will become larger.

Further, if L is increased in order to improve the creepage withstand voltage characteristics, new problems will arise. In other words, dielectric breakdown occurs between the inner diameter part of the conductor insertion hole 4 of the box side wall 2 and the internal fixed conductor 31, penetrating the cylindrical insulator 11.

Electrical equipment adopts a low value of withstand voltage characteristics as a usable voltage condition for safety reasons, so conventional insulators (bushings) that penetrate walls have almost no withstand voltage even if they are large. No improvement in characteristics could be expected. Moreover, increasing the size increases the weight, and there are also problems such as the installation work of the bushing being time-consuming.

An object of the present invention, based on the results of various experimental studies, is to provide a gas-insulated electric device having a conductor penetration structure that does not reduce dielectric strength voltage despite being small and lightweight.

E. Means for Solving the Problem The gas-insulated electrical equipment according to the first invention stores electrical equipment and conductors in a box body, and also seals insulating gas, and inserts the conductor through the side wall of the box body. In a gas-insulated electric device, the cylindrical insulator is provided on at least one side of the side wall of the box body, and the cylindrical insulator is provided on at least one side of the side wall of the box body. The gap dimension between the inner periphery of the conductor insertion hole provided in the side wall of the box body and the conductor is g, and the length of the inner wall of the cylindrical insulator is The size is l,
The inner diameter of the conductor insertion hole is φ1, and the inner diameter of the insulator is φ2.
When Q≧g/4, and L[''2≧2 mm
It is characterized by being set in the relationship of

In the second invention, a cylindrical insulator is provided to protrude outside the side wall of the box body, and its inner recessed part is filled with insulating gas, and the end of the internal fixed conductor provided inside the box body is connected to the conductor of the side wall of the box body. The insertion hole is loosely inserted into the cylindrical insulator, and the connecting conductor, which is provided with the cylindrical insulator airtightly and movably in the axial direction, is attached to the internal fixed conductor and can be freely connected and disconnected. In this configuration, the dimensions of the core part are g, Q, φ1. φ
2 is the second relationship, and the insertion dimension B of the internally fixed conductor into the cylindrical insulator is set to the relationship B≧−.

F. Results of Experiments 5F6yS The present inventor conducted various experiments regarding the insulation structure of the conductor penetration portion of the side wall of the box in gas-insulated electrical equipment. This will be explained below with reference to FIGS. 11 and 13.

The colors of the symbols in FIG. 17 and FIG. 20 are as shown in the table below.

Q - Length of the outer wall of the cylindrical insulator protruding outward from the side wall of the box (mm) φ1: Inner diameter of the conductor insertion hole (mm) φ,2 Inner diameter of the cylindrical insulator (mm) φ3: Cylindrical insulator Outer diameter (mm) g: Gap dimension between the inner circumference of the conductor insertion hole and the conductor (
+n+n) First, in a sealed box filled with SF8 at atmospheric pressure (approximately 0.10 MPa), a conductor insertion hole 4 is made in a flat plate 21 (thickness 1.2 mm) corresponding to the side wall of the box, as shown in Fig. 11. A conductor 3 (aluminum round bar) with a diameter of 30 mm was placed in the center of the conductor 3, and a high voltage was applied to conduct an experiment on the flash characteristics of the conductor penetration part. The inside of the box was evacuated in advance, and then filled with SF8 gas to atmospheric pressure (approximately 0.1 OMPa). Then, a voltage was applied to the conductor 3, the flat plate 21 was grounded, and flash voltage characteristics were determined. Figure 12 shows the results.
Hole diameter φ provided in the flat plate 21 when the diameter of the conductor 3 is constant
Impulse flash voltage characteristics of positive and negative polarity (50% F, 0
．． V,, kV). As can be seen from the figure, as the hole diameter φ1 increases, the withstand voltage characteristics for both positive and negative polarities increase proportionally.

Next, as shown in FIG. 13, a cylindrical (cup-shaped) insulator 11 with a boss portion 11b made of baked material having diameters of 1 to 2 and an inner wall length Q is attached to the side wall 2 of the box body. It is airtightly fixed to one side (outside) surface and also to the conductor 3, and the inside of the box and the insulator 11 are filled with SF and gas to atmospheric pressure (approximately 0.10 MPa), and the conductor penetration part is Experiments were conducted on flashover voltage characteristics.

That is, the hole diameter φ1 of the box side wall 2, the inner diameter φ2 of the cylindrical insulator 11, the gap dimension g between the conductor 3 and the hole of the box side wall 2,
A voltage was applied to the conductor 3 while changing each dimension as shown in the table below. Note that the outer diameter of the conductor 3 is 30 mm.

As shown in the previous table, FIG. 14 shows the flash fault voltage characteristics when the respective dimensions are changed.

As can be seen from FIG. 14, the flashover value when Q=O is lower for positive polarity than for negative polarity.

Then, as the inner wall length Q of the cylindrical insulator 11 is gradually increased, the flash voltage value increases significantly for positive polarity and gradually increases for negative polarity, and at a certain length Q, the polarity dependence increases. It turns out that things will turn around and eventually stop improving. This is because the flat plate 2, which is a metal member with an earth potential, is present, and the withstand voltage characteristics depend on this.

An example of a comparison between the results in Figure 14 and Figure 12 shows that as can be seen from this comparison, the withstand voltage characteristics are slightly improved in the case of Figure 13 than in the case of Figure 11. I understand.

Next, the withstand voltage characteristics due to the presence of the flat plate 21, which is a metal member, were investigated. In the experiment, the outer diameter of the conductor was 30 mm φ, = Q = 15 mm, g = 22.5 mm, other conditions were the same as in the case of Fig. 14, and the inner diameter dimension φ2 of the cylindrical insulator 11 was changed. In fact, the results shown in FIG. 15 were obtained.

That is, the horizontal axis in FIG. 15 shows that as the value of φ2 changes, the flashover voltage characteristics hardly change, but as the value falls below that, the characteristics suddenly deteriorate.

From the results of the above experiments (FIGS. 11 to 15), the following was found.

The reason why the positive polarity and negative polarity flash characteristics take the same value is (14th
(See figure), when g = 22.5, a x 5 mm, when Sg = 37.5, Q x 1. It is Omm. From now on, Q:g= 5:22.5 (1 year g/4Q:g=
lo: 37.5 (It is found that the relationship is 1g/4, and the length Q of the inner wall of the cylindrical insulator 11 is at least Q≧
It has been found that setting it to g/4 is effective for improving the dielectric strength voltage.

Furthermore, from the results shown in FIG. 14, it has been found that there is no effect even if the length ρ of the inner wall of the cylindrical insulator 11 is increased indefinitely. That is, φ,=75. φ,=80. At g=22.5,
At a Q of 75 or more, the flash characteristics hardly change for either positive polarity or negative polarity. Also, φ,=105. φt=110. When g=37.5, the withstand voltage characteristics hardly change for both positive and negative polarity at ff4105 or more. In other words, it has been found that regardless of the numerical value of g, as long as the length g of the inner wall of the cylindrical insulator 11 is approximately the same as the hole diameter φ, the withstand voltage characteristics will hardly improve even if it becomes longer.

Therefore, it has been found that the length Q of the inner wall of the cylindrical insulator 11 is preferably set to a minimum of Q≧g/4, preferably ρ minus φ1. Of course, there is no problem if Q>φ1, and in that case, there are requirements other than the withstand voltage characteristics, for example, a current transformer (CT
) is installed directly.

At the same time, the inner diameter φ2 of the cylindrical insulator 11 and the conductor through hole 4 are
It turned out that it would be better to make the diameter smaller).

In the case where the mixture of SF6 and air is
This study investigated the flash fault characteristics of the sidewall penetrating conductor in a box filled with e-gas, and it is known that a mixture of SFs gas and air has a higher withstand voltage than pure SFe gas at a certain ratio. ing.

Therefore, based on the above, the present inventor created a configuration as shown in FIG. The flash fault voltage characteristics were investigated by changing the ratio of both. An impulse voltage (1,2×50 μs) was applied to the conductor. The mixed gas ratio is 100% pure 5Fll gas.
Experiments were conducted by changing the mixing ratio of SF, gas, and air between 100% and 100% pure air.

The results of the experiment are shown in Figure 16, and it was found that as the mixing ratio of SF and gas increases, the withstand voltage increases and reaches its maximum value around 90% SF6. It was also found that it has voltage resistance characteristics equivalent to 1OO%SF.

Therefore, a mixed gas of SF and air (SF6 is 40
% or more, preferably around 90%), it has been found that it is more advantageous to improve the withstand voltage characteristics in the conductor penetration portion.

In this way, in the case of a mixed gas of SF and air, higher voltage resistance characteristics were obtained than pure SF depending on the mixing ratio, so the inventors conducted experiments with this mixed gas and further improved. The withstand voltage characteristics were investigated.

That is, the flashover voltage characteristics depending on the gap size g between the conductor 3 and the conductor insertion hole 4 and the flashover voltage characteristics depending on the end shape of the conductor insertion hole 4 were investigated.

Therefore, the structures shown in FIG. 17(A) and FIG. 17(B) had the best withstanding voltage characteristics. 90%5Fe-10
% air mixture was filled into the box and the cylindrical insulator [1] at a pressure similar to atmospheric pressure (approximately 0.1 OMPa), and the length dimension ρ of the inner wall of the cylindrical insulator 11 was varied. , the withstand voltage characteristics based on the gap dimension g between the conductor 3 and the conductor insertion hole 4 were investigated while examining the dependence of the four dimensions.

In addition, in FIGS. 17(A) and 17(B), the thickness of the box side wall 2 is 1.2 mm, and the outer diameter of the conductor 3 is 30 mm. In addition, the inner diameter dimension φ of the cylindrical insulator 11 was determined based on the experimental results shown in FIG. 15 so that the presence of the cylindrical insulator 11 could be sufficiently ignored.

is 10 mm from the inner diameter dimension φ of the conductor insertion hole 4.
It is made larger (φ2=φ++10mm). Also, the first
The conductor insertion hole 4 in FIG.
The conductor insertion hole 4 shown in FIG. 7(B) is bent with a radius of 10 mm to reduce the electric field.

The experiment was conducted using a negative polarity impulse voltage (1,2 x 50 μs)
(This is based on the fact that the withstand voltage characteristics are worse with negative polarity than with positive polarity, so if you examine it with negative polarity, you can clearly see the tendency of the characteristics.) The results were as shown in FIG. 18(A) and FIG. 18(B). In FIG. 18, the horizontal axis shows the gap size gmm between the conductor 3 and the conductor insertion hole 4, and the vertical axis shows the negative polarity impulse flash voltage characteristics (50%, P, O, V, , kV).

The following was found from the figure.

(1) From the results in Figures 18 (A) and (B),
Figure (A).

When both structures in (B) are pure SF (Figure 12)
It was confirmed that the withstand voltage characteristics were improved compared to .

(2) From the results shown in Figure 18 (A), in the structure shown in Figure 17 (A), if the gap dimension g is 20 + nm or more, the inner wall length dimension Q is approximately the same in the range of 220-1O0ffI. It was confirmed that the Q dimension is not affected by the withstand voltage characteristics as long as the Q dimension is above a certain level.

(3) From the results shown in FIG. 18 (B), the structure shown in FIG. 17 (B) shows almost the same withstand voltage characteristics when Q is in the range of 40 to LOOmm, although it is low when Q is in the range of 0 to 10 mm. It was confirmed that the Q dimension does not affect withstand voltage characteristics as long as the ρ dimension is above a certain level.

(4) Furthermore, when comparing Fig. 18 (A) and (B),
In the case of Fig. 18 (B), that is, in the case of the structure in which the inner peripheral side of the conductor insertion hole 4 is bent to alleviate the electric field as shown in Fig. 17 (B), the withstand voltage characteristics are slightly higher (approximately 5 kV). ) It turns out that although there has been an improvement, there is almost no difference between the two.

Based on the above results, the inventors conducted a more detailed investigation.

That is, since it is good for the cylindrical insulator 11 to be as short as possible in terms of size and weight reduction, the withstand voltage characteristics depending on the four dimensions were investigated in detail. The experimental conditions are shown in Figure 17 (
A), (B), Figure 18 (A).

Under the same conditions as in case (B), and with the second dimension set to 22.5 mm.
and 37.5 mm (see the table below), the withstand voltage characteristics were investigated by varying the four dimensions.

As a result, the results shown in FIG. 19 were obtained. For comparison, the results shown in FIG. 14 (negative polarity impulse) are shown together with dotted lines.

The following was found from the results shown in FIG.

(1) It was confirmed that the withstand voltage characteristics were improved compared to pure 5F6 (results shown in FIG. 14).

(2) In the case of the configuration shown in FIG. 17(B), the configuration shown in FIG. 17(A)
It was found that although the withstand voltage characteristics were better than those with the configuration, there was almost no difference between the two.

From the above results (Figures 17 to 19), it is clear that the shape of the inner circumferential side of the conductor insertion hole 4 provided in the side wall 2 of the box body has almost no effect on the withstand voltage characteristics, and that It is sufficient to drill holes in the hole and remove the holes (see Figure 17 (A)), but it is necessary to curve the surface (or attach a ring) as shown in Figure 17 (B) to alleviate the electric field. It turned out that there was no need to take any action.

Summary of the above experiments To summarize the above, the following can be said.

(1) Gap dimension g between the inner circumference of the conductor insertion hole and the conductor
and the length dimension Q of the inner wall of the cylindrical insulator is expressed as e≧g/
4.

(2) Q dimension is equivalent to the inner diameter dimension φ8 of the conductor insertion hole (Q'
=φI).

(3) The relationship between the inner diameter dimension φ of the conductor insertion hole and the inner diameter dimension φ2 of the insulator should be L[]-≧2□.

(4) Rather than using pure SF gas, a mixed gas of SF and air with SF of 40% or more, preferably around 90%, has better voltage resistance characteristics.

(5) It has been found that the shape of the inner periphery of the conductor insertion hole has little effect on withstand voltage characteristics, and it is possible to remove pars around the drilled hole without performing complicated processing to alleviate the electric field. It should be sufficient.

New Experiments Based on the results obtained from the above experiments, the inventor further conducted the following experiments. That is, the cylindrical insulator 1
This is an experiment to form a disconnection section within 1.

In other words, in the experiment described above, the conductor 3 penetrated the box side wall 2 to a sufficient length, whereas as will be explained later in FIG. Is it possible to make it smaller? Therefore, whether there is a difference between the case where the end of the conductor 3 that slightly penetrates the box side wall 2 is located inside the cylindrical insulator 11 and the above experimental results, and under what conditions there is a difference. This is to check whether the The experiment is the 20th
The experiment was carried out using the configuration shown in the figure. In Fig. 20, the inner diameter of the conductor insertion hole, φ, = 75 mm, the inner diameter of the cylindrical insulator, φ2 = 85 mm, the gap dimension between the inner circumference of the conductor insertion hole and the conductor, g =
22.5 mm Conductor diameter = 30 mm The inner wall of the cylindrical insulator 11 is sufficiently long (inner wall 1
5mm), and the gas filled in the box and the inner recessed part of the cylindrical insulator 11 is: ■90%5F8-10% air (Fig. 21...)■
The gas pressure was atmospheric pressure (approximately 0.10λ).
1 Pa).

The results are shown in FIG. 21 (only for negative polarity impulses). That is, it has been found that stable voltage resistance characteristics can be obtained if the insertion dimension B of the conductor 3 into the cylindrical insulator 11 is approximately 5 mm or more. In other words, I knew it would work.

If the conductor passes through the through hole 4 of the body side wall 2 and enters the cylindrical insulator 11, results similar to those shown in FIGS. It was confirmed that it was possible to form a disconnection section.

G. Examples Six examples of the cylindrical insulator according to the present invention based on the results supported by the various experiments described above are shown in FIGS. 1 to 8, and will be described below.

First Embodiment In the first embodiment shown in FIG. 1, 5 is a box body such as a switchgear that houses electrical equipment and is filled with an insulating gas such as pure SF6 gas or a mixed gas of 5Fll and air; In the figure, it is on the right side of the box side wall 2 or inside the box,
Filled with gas. The cylindrical insulator 11 has a flange portion 11a and a boss portion 11b.
The port 20 is attached to the outside of the box side wall 2 via a sealing material 23.
It is fixed in place. Boss part 1 of cylindrical insulator 11
1b through a long conductor 3 or a sealing material 22 in an airtight manner. The inside concave portion 24 of the cylindrical insulator 11 is filled with the same insulating gas as the inside of the box 5.

Further, the specific dimensions in FIG. 1 are as follows: conductor diameter -30 mm g = 30 mm φ, = 90 mm φ2 = 95 mm Q = 30 mm.

In the first embodiment, the length of the inner wall of the cylindrical insulator 11 and the gap dimension g between the conductor insertion hole 4 provided in the box side wall 2 and the conductor 3 are determined as Q=g based on the above-mentioned experimental results. It's Toshide. Furthermore, we are in the first example. In other words, the inner wall dimension of the cylindrical insulator 11 is larger than the conductor insertion hole 4,
The inner wall of the conductor insertion hole 4 protrudes inward (towards the conductor 3) by about 2.5 mm. Note that the inner wall of the conductor insertion hole 4 is approximately 2.5 m long.
The fact that it protrudes inward is the same as in the second to sixth embodiments described below. Further, the conductor insertion hole 4 has a peripheral wall that is smoothed.

This eliminates the need to increase the length of the cylindrical insulator 11 unnecessarily, and further reduces the size, which is a characteristic of gas insulation. However, it is light in weight and small in size, making it easy to handle.

Second Embodiment In the second embodiment shown in Figures 2 and 3, 5゜5 is an opening/closing unit that houses electrical equipment and is filled with an insulating gas such as pure SF6 gas, SP, or a mixture of gas and air. They are two boxes that look like devices. Each box side wall 2, 2
They are arranged at regular intervals, and are connected by a cylindrical insulator 11. Both side flanges 11a of the cylindrical insulator 11 are abutted against the box side wall 2 with a sealing material 6 interposed therebetween, and are hermetically fixed with bolts and nuts.

The conductor 3 is guided from one box 5 to the other box 5 by passing through the center of the cylindrical insulator 11, and is supported by a support insulator 7 attached to the inner wall of each box 5, 5. ing.

In the second embodiment, the conductor 3 is of one phase,
The cylindrical insulator 11 has a circular cross section. This second
Also in the embodiment, the length Q of the inner wall of the cylindrical insulator 11,
The gap dimension g between the conductor insertion hole 4 provided in the box side wall 2 and the conductor 3 is set to σ>g/4 based on the results of the experiment described above. Also in the second embodiment, φ2>φ1 and 42.5 mm.

Third Embodiment FIG. 4 shows a third embodiment, and while the second embodiment had one phase, this third embodiment shows a three-phase example, and accordingly, the cylindrical insulator 11 The cross-sectional shape is different from that in FIG. 3, and the cross-sectional structure allows the three-phase conductors 3, 3.3 to be inserted all at once. In this case, the dimensional conditions of the length a of the inner wall of the cylindrical insulator 11 and the gap dimension g are set to satisfy Q>g/4.

FIG. 5 of the fourth embodiment. FIG. 6 shows a fourth embodiment, in which the cross-sectional shape of the cylindrical insulator 11 in the three-phase case is circular, unlike the case in FIG. 4. In this case, the dimensions a and g of the cylindrical insulator 11 are set to 12>g/4.

Fifth Embodiment FIG. 7 shows a fifth embodiment. In this fifth embodiment,
One end of the cylindrical part of the cylindrical insulator 11 is hermetically fixed to the outside of the box side wall 5 via a sealing material 6 with bolts and nuts, and the other end of the cylindrical part of the cylindrical insulator 11 is , and is airtightly fixed to the conductor 3, and is provided with folds 8 on the outer periphery of the adhesion part to extend the creepage distance in the atmosphere. This fifth
In the embodiment as well, the length Q of the inner wall of the cylindrical part of the cylindrical insulator 11, the hole diameter φ1 of the conductor insertion hole 4 in the box side wall 2, and the gap dimension g between the conductor insertion hole 4 and the conductor 3 are ρ> It is configured in a relationship of g/4 (including σ x g/4).

If necessary, under the above conditions, a cylindrical insulator 11 is also provided inside the box side wall 2 as shown by the two-dot chain line in FIG. There is no problem even if the other end side is fixed to the conductor 3, and thereby the conductor can be supported reliably. The inside of the cylindrical insulator 11 can be filled with the same insulating gas as inside the box (in this case, a hole is opened in the side wall of the box to allow communication), or the inside of the cylindrical insulator 11 can be sealed and pressurized gas can be put in there. It's okay.

Sixth Embodiment FIG. 8 shows a sixth embodiment in which the end of the internal fixed conductor 31 is located in the inner recess 24 of the cylindrical insulator 11, and the disconnection part 9 is formed in the recess. show. That is, in FIG. 8 (showing the disconnected state), 32 is a connecting conductor, which allows the boss portion 11b of the cylindrical insulator 11 to be airtightly moved in the axial direction (left and right directions in the figure) via the sealing material 22. Penetrating. Reference numeral 14 denotes a positive ring provided on the connecting conductor 32 so that the connecting conductor 32 cannot be pulled out.

The outer periphery of this connection conductor 32 may be covered with an insulating material.

Moreover, a multi-contact 13 is provided inside the tip of the internal fixed conductor 31 located inside the box, and when the connecting conductor 32 moves to the right in FIG. 8, it fits into the multi-contact 13 and the internal fixed conductor 31. Also,
The tip of the internal fixed conductor 31 enters the concave portion 24 from the opening of the cylindrical insulator 11 by three dimensions (215 or more). Note that the cylindrical insulator 11 is attached to the side wall 2 of the box housing the electrical equipment in the same manner as in the first embodiment.
Identical parts are given the same reference numerals and explanations will be omitted.

In FIG. 8, internal fixed conductor diameter = 30 mm Disconnection gap dimension G = 45 mm g = 30 + nm φ+ = 90 mm φz = 95 mm B = 18 mm σ = 110 mm g, φ1. φ2. The dimensional relationship is the same as in the first embodiment.

1 (Specific Application Example First Application Example FIG. 9 shows a switchgear 1 to which the cylindrical insulator 11 according to the first embodiment of FIG. 1 is applied. In the figure, a switchgear 1 filled with an insulating gas A cylindrical insulator 11 is provided on the outside of the box side wall 2 (that is, on the breaker room side) that partitions the bus room 15 side and the breaker room IO side, and is connected to the power bus and the load side cable in the bus room 15. The internal fixed conductors 31 hermetically penetrate the boss portions 11b of the cylindrical insulators 11 and protrude toward the breaker chamber 10.The figure also shows that the drawer-type breaker 18 is being carried into the breaker chamber 10. This shows a connected state in which the external conductor 19 and the internal fixed conductor 31 are connected.Other configurations are the same as the conventional example shown in FIG.

Second Application Example FIG. 10 shows an insulating gas-filled opening/closing device l to which the cylindrical insulator (bushing) 11 according to the sixth embodiment of FIG. 8 is applied. In the figure, the point that a cylindrical insulator 11 is provided outside the box side wall 2 (that is, on the breaker chamber side) is the same as in the first application example. The connecting conductor 32 passes through the boss portion 11b of the cylindrical insulator 11 in an airtight and slidable manner.
In the busbar chamber 15, the tip of the internal fixed conductor 31 connected to the power supply side busbar and the load side cable is moved inward from the opening edge of the cylindrical insulator 11 by a predetermined dimension (i.e., 8 as shown in FIG. 8).
Dimensions) are included.

The same figure also shows a state in which the draw-out breaker 18 has been carried into the breaker chamber 10 and immediately before connection.
The outer end of the connecting conductor 32 is in contact with the outer conductor 19 of the draw-out breaker 18. By further pushing the pull-out breaker 18 from this state, the connecting conductor 32 moves inward and comes into contact with the internal fixed conductor 31 to be in a connected state. The other configurations are the same as the first application example.

In addition, in the second application example, the disconnection part 9 is formed in the recessed part 24 filled with the insulating gas of the cylindrical insulator 11 (that is, the connection conductor 32 and the internal fixed conductor 31
Since the draw-out breaker 18 and the internal fixed conductor 31 of the switchgear 1 are disconnected in an insulating gas, as shown in When the circuit is disconnected in the breaker chamber 10), the dielectric strength is improved from the beginning, and in this respect, the insulation space can be reduced, and the switchgear can be further downsized.

■ Effects of the Invention According to the present invention (this gas-insulated electrical equipment), a cylindrical insulator surrounding a conductor penetrating the side wall and whose inside is filled with the same insulating gas as the inside of the box body is attached to the side wall of the box body. The length Q of the inner wall of the cylindrical insulator attached to one side and the gap dimension g between the conductor insertion hole and the conductor provided in the side wall of the box are ρ≧g/
4, and the through hole φ1 in the side wall of the box body and the inner diameter φ of the cylindrical insulator
The relationship with 2 is φ2−φ.

2 ≧2mm, the size is smaller than that of a conventional cylindrical insulator that is provided by penetrating the side wall of the box inside and out, and the insulation properties are not deteriorated in any way.
Therefore, the size of the opening/closing device can be reduced.

Furthermore, particularly in the second invention, the disconnecting portion is provided in the recessed portion of the cylindrical insulator filled with insulating gas, and the internally fixed conductor is inserted into the recessed portion beyond the conductor insertion hole in the side wall of the box body. By setting the insertion dimension B of the internally fixed conductor into the cylindrical insulator as B≧1 and keeping the other conditions the same as in the first invention, the withstand voltage can be increased as in the first invention. The characteristics are well stabilized, and the disconnecting portion can be formed with smaller dimensions than before without deteriorating the insulation characteristics, allowing the switchgear to be further miniaturized.

[Brief explanation of drawings]

1 to 8 show the first to sixth embodiments of the present invention, and FIG. 1 is a cross-sectional view of the first embodiment of the portion where the conductor penetrates the side wall of the box body in gas-insulated electrical equipment; Fig. 2 is a sectional view of the second embodiment, Fig. 3 is a sectional view of Fig. 2, and Fig. 4 is a sectional view of the third embodiment.
5 is a sectional view of the fourth embodiment; FIG. 6 is a sectional view of FIG. 5; FIG. 7 is a sectional view of the fifth embodiment;
The figure is a sectional view of the sixth embodiment, FIG. 9 is a schematic diagram of a switchgear shown as a first application example, FIG. 10 is a schematic diagram of a switchgear shown as a second application example, and FIG. A sectional view of an experimental model of a conductor penetration part in which a conductor is passed through a hole in a grounding plate. Figure 12 is a flash fault voltage characteristic diagram in Figure 11.
Figure 3 is a cross-sectional view of an experimental model of a conductor penetration using a cylindrical insulator that is in close contact with the side wall of the grounding box and the conductor inserted through the hole in the side wall. Figure 14 is the flash fault voltage characteristic diagram of Figure 13. Fig. 15 is a flash fault voltage characteristic diagram when the inner diameter of the cylindrical insulator is increased in the experimental model of Fig. 13, Fig. 16 is a flash fault voltage characteristic diagram in a mixed gas of SFe gas and air, and Fig. 17 (
A) and (B) are the other two conductor penetration parts using a cylindrical insulator that is in close contact with the side wall of the grounding box body and the conductor that is inserted into the hole in the side wall, which is different in size or structure from the one in Figure 13. Cross-sectional views of two experimental models, Fig. 18 (A), (B), Fig. 17 (,A),
(B) flash fault voltage characteristic diagram, Figure 19 is Figure 17 (A),
(B) is a flashover characteristic diagram in relation to the length of the inner wall of the cylindrical insulator, FIG. Figure 21 is a flashover characteristic diagram for each dimensional relationship in Figure 20, Figure 22 is a flashover characteristic diagram for changes in dimensions in Figure 23, and Figure 23 is a flashover characteristic diagram for each dimension relationship in Figure 20.
The figure is a sectional view modeling and showing the conventional wall-penetrating bushing shown in Fig. 24, Fig. 24 is a sectional view of the conventional wall-penetrating bushing, and Fig. 25 is a schematic diagram of a switchgear to which the wall-penetrating bushing is applied. be. 2 - Box side wall, 3... Conductor, 31... Internal fixed conductor, 32... Connection conductor, 4... Conductor insertion hole, 5...
Box body, 9... Disconnection section, 11... Cylindrical insulator, Q...
- Length of the inner end of the cylindrical insulator, φ1... Hole diameter of the conductor insertion hole, g... Length of the gap between the conductor and the conductor insertion hole, B... The length of the internally fixed conductor to the cylindrical insulator Insertion dimensions. 11--One cane zetsu a- Hem 1 inch Fig. 1 Fig. 15 φ2-φ1 Fig. 16 5F6-tL3#-Gas&'l l'Q, E 5
tf (・p* Zosa), %o50 too 5
F6 ('/,) 50 0 Age (%) Fig. 1S (A) Q (mm) Fig. 1S (B) 9 (mm) Fig. 21 B mm Fig. 22 S Five special small tips (six J (pressure → cold J)
L L (mm) Fig. 23 61 3 S Showa fl Month 11

Claims (2)

[Claims] (1) Electrical equipment, conductors, etc. are housed inside the box, and an insulating gas is filled in, the conductor is provided through the side wall of the box, and the conductor is surrounded and hermetically fixed to the side wall. In a gas-insulated electric device provided with a cylindrical insulator, the cylindrical insulator is provided on at least one side of a side wall of a box body, and is configured such that gas is present inside, and the insulator is provided on a side wall of a box body. The gap between the inner periphery of the conductor insertion hole and the conductor is g, the length of the inner wall of the cylindrical insulator is l, the inner diameter of the conductor insertion hole is φ_1, and the inner diameter of the insulator is φ_2. When l≧g/ and (φ_2−
A gas insulated electrical device characterized by having a relationship of φ_1)/2≧2mm. (2) A cylindrical structure that houses electrical equipment and an internally fixed conductor inside the box, fills it with insulating gas, has a conductor penetrating the side wall of the box, and surrounds the conductor and is airtightly fixed to the side wall. In the gas-insulated electrical equipment provided with an insulating material, the cylindrical insulating material protrudes to the outside of the side wall of the box body, and an inner concave portion thereof is filled with an insulating gas, and an end of the internal fixed conductor has a cylindrical shape. A conductor insertion hole in the side wall of the box body is provided so as to be located inside the insulator, and a connecting conductor is provided so as to freely pass through the conductor insertion hole in the side wall of the box, and to be able to freely approach and separate from the internal fixed conductor, to penetrate the cylindrical insulator in an airtight manner, and to be movable in the axial direction. A disconnection section between the connecting conductor and the internally fixed conductor is formed in the cylindrical insulator, and the gap dimension between the inner periphery of the insertion hole provided in the side wall of the box and the internally fixed conductor is g, and the cylindrical insulator is When the length of the inner wall of is l, the inner diameter of the conductor insertion hole is φ_1, the inner diameter of the cylindrical insulator is φ_2, and the insertion dimension of the internally fixed conductor into the cylindrical insulator is B, then l
≧g/4, (φ_2-φ_1)/2≧2mm, and B
A gas-insulated electrical device characterized by having a relationship of ≧g/2.