JP2560374Y2 - Three-phase batch vacuum circuit breaker - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-phase collective vacuum circuit breaker used for power circuits such as power transmission and substations.

[0002]

2. Description of the Related Art Vacuum circuit breakers are widely used because of their excellent breaking performance and high reliability. In addition, the vacuum valves serving as current interrupting points are housed one by one in a cylindrical grounded container filled with insulating gas such as SF6 gas, so that the current interrupting and the insulation inside the vacuum valve are borne by vacuum, and the outside of the vacuum valve is A tank-type vacuum circuit breaker is used in which the insulation of the creepage is shared by the insulating gas and the size is reduced. FIG.
FIG. 4 shows an example of the entire structure of a conventional three-phase tank-type vacuum circuit breaker, and FIG. 4 shows a cross-sectional structure of one phase of the circuit breaker main body 1 in FIG. 3 and 4, reference numeral 2 denotes a closed container having a cylindrical cross section, and 3 denotes a vacuum valve, which is fixed by an insulating spacer 4 to the closed container 2 at a ground potential while maintaining insulation. Reference numeral 5a denotes a first through bushing, which is fixed to a first branch pipe portion 6a planted at one end of the closed casing 2. 7a is a terminal block connected to the external electric wire 8a,
At the upper end of the first through bushing 5a, the insulating gas 9 sealed in the first through bushing 5a and the sealed container 2 is sealed, and one end of the vacuum valve 3 penetrates through the first through bushing 5a. 1st conductor 1 electrically connected to
0a. The branch pipe portion 6a of the closed container 2
At the opposite end, there is a second branch 6b,
The terminal block 7b connected to the external electric wire 8b, the second conductor 10b, and the second through bushing 5b are installed similarly to the branch pipe portion 6a side. It is appropriate to use a medium having a high insulating performance such as SF6 for the insulating gas 9.
And the first and second through bushings 5a, 5b are collectively filled. FIG. 4 shows the structure of only one phase of the circuit breaker main body 1, but the other two phases have substantially the same structure. 1
Reference numeral 1 denotes a gas pipe for communicating the insulating gas 9 of the three-phase closed container 2. That is, in order to monitor the insulating gas 9 economically, the three-phase insulating gas 9 is shared by the gas pipe 11.

An operation device 12 for opening and closing the circuit breaker is mounted on a gantry 13. 14 is a drive mechanism,
A drive rod 15 for connecting the operating device 12 to the first phase of the circuit breaker body 1, a rod 16a for connecting the first and second phases of the circuit breaker body 1, and the second and third phases of the circuit breaker body 1, respectively. ,
16b, a lever 17 for changing the direction of the operation force, and the like. Reference numeral 18 denotes an insulating rod, which is a lever 17 and a vacuum valve 3.
Between the drive rod 15 and the rod 1
The operating forces of 6a and 16b are transmitted to the vacuum valve 3. The insulating gas 9 is rotatably sealed from the atmosphere by a sealing device 19 provided on the lever 17. 20 is the drive rod 1
5 is a cover for shielding the rods 5 and the rods 16a and 16b from wind and rain. This circuit breaker is a three-phase tank-type vacuum circuit breaker in which the three-phase circuit breaker body 1 is operated collectively by the operation device 12.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a three-phase collective vacuum circuit breaker which solves the following problems in conventional equipment. (1) The conventional three-phase tank-type vacuum circuit breaker combined with gas insulation has a large number of parts and a cylindrical closed container because each of the three phases is housed in an independent cylindrical closed container. It is expensive because of its complicated structure, such as the necessity of a branch pipe portion for implanting an insulator pipe so as to be substantially perpendicular to the pipe. (2) The number of parts and the number of gas seal locations are large, and there are many factors that reduce reliability. (3) A gas pipe connecting between the closed containers tends to be a weak point in strength.

[0005]

According to the invention of claim 1, an octahedron in which two opposing portions are formed as inclined surfaces out of four orthogonal portions composed of an upper horizontal plane and four vertical surfaces of a rectangular parallelepiped. A closed container, an insulating gas sealed in the closed container, a three-phase vacuum valve installed at a predetermined distance in the closed container, and a three-phase vacuum on one of the inclined surfaces of the closed container. A three-phase first having a first conductor communicating between the inside and the outside of the closed container, which is provided at a position corresponding to each of the valves.
And a three-phase second through bushing provided with a second conductor communicating between the inside and the outside of the closed container, which is provided on the inclined surface of the closed container opposite to the first through bushing, The three through-phases are connected from one through-bushing side to a second through-bushing side via a vacuum valve. According to a second aspect of the present invention, in the first aspect, the insulating gas is substantially 90% SF6 and approximately 1%.
Consist of a mixture of 0% dry air or nitrogen.

[0006]

According to the first aspect of the present invention, the closed container can be constituted by one for the three-phase circuit breaker body. Also, since the through bushing can be implanted directly in the closed container by being inclined, the insulation interval on the air side between the three-phase first through bushing and the second through bushing is increased, and the number of parts and gas are reduced. The number of seal locations is reduced. Further, a gas pipe connecting the three phases is not required.
According to the invention of claim 2, in addition to the operation of the invention of claim 1, pure SF can be obtained by applying a mixture of approximately 90% of SF6 and approximately 10% of dry air or nitrogen.
It is possible to provide a circuit breaker with better insulation characteristics than 6 gases.

[0007]

1 shows the overall structure of a three-phase vacuum circuit breaker according to the present invention, and FIG. 2 shows a cross-sectional structure of one phase of the circuit breaker main body 21 of FIG. 3 and 4 are assigned the same reference numerals for convenience of comparison. In FIGS. 1 and 2, reference numeral 22 denotes an octahedral closed container in which two opposing portions are formed on inclined surfaces, out of four orthogonal portions formed by a rectangular parallelepiped upper horizontal plane and four vertical surfaces, and 3 is a vacuum valve. The three phases are separated by a predetermined distance, and fixed in parallel with the bottom surface of the sealed container 22 to the sealed container 22 at the ground potential by an insulating spacer 23 while maintaining insulation. 5a is the first
, The first inclined surface 24 of the closed container 22
a, which is fixed at a position corresponding to the vacuum valve 3.
Reference numeral 7a denotes a terminal block connected to the external electric wire 8a. The upper end of the first through bushing 5a seals the first through bushing 5a and the insulating gas 9 sealed in the sealed container 22, and the first through bushing 5a. It is connected to a first conductor 25a that penetrates through the through bushing 5a and is electrically connected to one end of the vacuum valve 3. The second inclined surface 24b of the closed container 22 opposite to the first inclined surface 24a has a terminal block 7b connected to the external electric wire 8b and a second conductor 25b, similarly to the first inclined surface 24a. , A second through bushing 5b is provided. In this structure, the first and second inclined surfaces 24a, 24 for implanting the first and second through bushings 5a, 5b are provided.
b is sufficient as long as the fastening member 26 such as a bolt used for fixing the first and second through bushings 5a and 5b is only required to have a thickness that does not impair the sealing of the sealed container 22. The container 22 may be composed of a thicker member, or the first and second inclined surfaces 24a and 24b may be formed of a flange 2
It is only necessary to have a thick structure with the addition of 7, and the structure is extremely simple. Also, since the three-phase first and second through bushings 5a, 5b are all mounted at an angle, the air insulation interval between the three-phase first and second through bushings 5a, 5b can be increased. The size of the closed container 22 can be reduced. Since the insulating gas 9 having excellent insulation performance is sealed in the closed container 22, even if the closed container 22 is made small, there is no problem in insulating design. FIG. 2 shows the structure of only one phase of the breaker body 21, but the other two phases have substantially the same structure. Since the three-phase structure is substantially the same by arranging the vacuum valve 3 in parallel with the bottom surface of the sealed container 22, the insulating spacer 23 and the first and second conductors 25a and 25b are unified and manufactured. There is an advantage that it is easy to do. Further, connection for collectively operating the three-phase circuit breaker main body 21 is also easy. Ease of production means economy,
This is convenient for providing a highly reliable device.

Reference numeral 12 denotes an operating device for opening and closing the circuit breaker, which is mounted on a gantry 13. 28 is a drive mechanism,
A driving rod 29 for connecting the operating device 12 to the first phase of the circuit breaker body 21, a rod 1 for connecting the first and second phases of the circuit breaker body 21, and the second and third phases of the circuit breaker body 21, respectively.
6a and 16b, a lever 17 for changing the direction of the operation force, and the like. Reference numeral 18 denotes an insulating rod that insulates the lever 17 from the vacuum valve 3 and transmits the operating force of the drive rod 29 and the rods 16a and 16b to the vacuum valve 3. The insulating gas 9 is rotatably sealed from the atmosphere by a sealing device 19 provided on the lever 17. A cover 30 shields the drive rod 29 and the rods 16a and 16b from the weather. This circuit breaker is a three-phase collective vacuum circuit breaker in which the three-phase circuit breaker main body 21 is operated collectively by the operation device 12.

Now, the insulating gas 9 filling the inside of the sealed container 22 and the first and second through bushings 5a, 5b is as follows.
A gas having a high insulation performance such as SF ₆ is effective for downsizing the circuit breaker. However, in the case of the non-uniform electric field structure, a mixed gas of approximately 90% SF 6 and approximately 10% dry air or nitrogen is used. It is known that insulating properties are superior to pure SF6 gas. (For example, Electro-Electronics Magazine No. 107
Vol. 2, No. 1987) The vacuum circuit breaker of the present invention houses the three-phase vacuum valve 3 collectively in a closed container 22 composed of a flat surface, and has a concentric circular structure and an equal electric field design. It is more difficult to make the electric field structure equal to that of the conventional vacuum circuit breakers of FIGS. 3 and 4 using a cylindrical container which is easy to use. By using a mixed gas of dry air or nitrogen, a three-phase batch vacuum circuit breaker having better insulation performance can be obtained.

Since the insulating gas 9 such as pure SF6 or a mixed gas of SF6 has high insulating performance, the outer surface insulation of the vacuum valve 3 can be sufficiently secured even at a low pressure. On the other hand, in the closed container 22 composed of a flat surface, a bending stress acts on the flat surface due to pressure, and deflection is easily generated.
Not suitable for use at high pressures. However, in the case of the present invention, since the upper surface of the closed vessel 22 is provided with an inclined surface, the individual planes become smaller and have a reinforcing effect on strength, so that a relatively high pressure can be obtained without special reinforcement. Can withstand. On the other hand, the bottom side of the sealed container 22 has a structure such as attachment to the gantry 13 or the sealing device 19 and has a high strength. Therefore, no special reinforcement is required. It is possible. However, even if the strength is maintained as described above, in the case of a cylindrical container, the deformation due to the internal pressure becomes a tensile stress and the deformation is slight compared to the case where the structure mainly consists of a flat surface. There are basically weak points that are easy to do. The present invention overcomes this weak point with a structural device. As a result, it is desirable that the insulating gas 9 sealed in the closed container 22 having the planar structure as in the present invention has a low pressure. In this case, if the pressure is set to 2 kgf / cm ² or less, a low-pressure structure with high safety that is not applicable to the pressure vessel structure standard according to the notification of the Ministry of Labor is obtained.

Further, the inside of the closed container 22 is vacuum-pulled, that is, the pressure in the closed container 22 is reduced with respect to the external pressure of 0 kgf / cm ^2.
At 1 kgf / cm ² , the pressure difference between the inside and outside of
kgf / cm ^2, and put the insulating gas 9
When encapsulating, the maximum operating pressure of the insulating gas 9 is 1 k
If the pressure is set to gf / cm ² , the effect on the strength of the plane constituting the closed container 22 is exerted even if there is a difference between the internal pressure and the external pressure acting on the closed container 22 when vacuuming is applied. Are almost the same, which is the most economical design in terms of the strength design of the sealed container 22. Maximum operating pressure is 1kgf / c
Conditions to be m ^2, the upper limit of the operating temperature, by applying an electrical Engineers electrical standards Committee Standard JEC-2300-1985 is a typical standard being applied to a circuit breaker, if the silver connection, the contact portion With the temperature rise limit of 65 ° C., 105 ° C. is obtained in combination with the upper limit of the ambient temperature of 40 ° C. Practically, the temperature of the insulating gas 9 does not rise as high as the contact portion. Therefore, if the temperature of the insulating gas rises by 20 to 60 ° C. to reach 60 to 100 ° C., the reference temperature is set to 20 ° C. Is proportional to the absolute temperature, so that the normal pressure P is obtained as P = 2 × (273 + 20) / {273+ (60-100)} − 1 = 0.76-0.57 kgf / cm ² . From this, the normal pressure at 20 ° C. is 0.8
If it is set in the range of 0.5 kgf / cm ^2, the sealed container 2
2, the most economical design is possible.

[0012]

[Effect of the Invention] Since only one closed vessel is required for the three-phase vacuum valve, it can be constituted by a small number of members. In addition, the closed container is reinforced by rationally utilizing the structural feature of the inclined surface without adding any members. Furthermore, since the through bushing can be implanted directly in the closed container and can be directly implanted, the structure is simple, and since the first and second through bushings are mounted at an angle, the aerial dimensions can be increased. The container can be miniaturized. Therefore, it can be manufactured in a short time and is economical. Further, as the number of parts is reduced and the number of gas seal locations is reduced, the cause of gas leakage is reduced and reliability is improved. Further, gas piping for connecting the three phases is not required, which is more economical and eliminates weaknesses in strength.

[Brief description of the drawings]

FIG. 1 is an overall structural view of a three-phase collective vacuum circuit breaker of the present invention.

FIG. 2 is a sectional structural view of a main body portion of the three-phase collective vacuum circuit breaker of the present invention.

FIG. 3 is an example of the overall structure of a conventional three-phase tank type vacuum circuit breaker.

FIG. 4 is an example of a sectional structural view of a main body of a three-phase tank type vacuum circuit breaker having a conventional structure.

[Explanation of symbols]

 Reference Signs List 3 vacuum valve 5a first through bushing 5b second through bushing 9 insulating gas 12 operating device 18 insulating rod 19 sealing device 21 circuit breaker body 22 closed container 23 insulating spacer 24a first inclined surface 24b second inclined surface 25a First conductor 25b Second conductor 28 Drive mechanism

Claims (2)

(57) [Scope of request for utility model registration] 1. An octahedral closed container in which two opposing portions of a rectangular parallelepiped are formed of an upper horizontal surface and four vertical surfaces, and two opposing portions are formed on inclined surfaces, and an insulating member sealed in the closed container. Gas and in the closed container , horizontally and at a predetermined interval.
And a three-phase vacuum valve fixed via an insulating spacer, and the closed container connected to one end of the vacuum valve.
A first conductor that conducts between the inside and the outside of the three-phase vacuum chamber.
Lube and a predetermined space at the corresponding position,
A three-phase first through bushing installed on one of the inclined surfaces of the closed container , connected to the other end of the vacuum valve and connected to the closed container;
A second conductor for conducting between the inside and outside of the vessel, and the three-phase vacuum
Separate predetermined spaces at positions corresponding to valves.
And a three-phase second set on the other of the inclined surfaces of the closed container .
Three-phase type vacuum circuit breaker characterized by comprising a through bushing, the. 2. The three-phase vacuum circuit breaker according to claim 1, wherein the insulating gas comprises a mixture of approximately 90% SF6 and approximately 10% dry air or nitrogen.