WO2022121873A1

WO2022121873A1 - Wall bushing

Info

Publication number: WO2022121873A1
Application number: PCT/CN2021/135966
Authority: WO
Inventors: 钟建英; 张进; 高远; 柴影辉; 段晓辉; 谭盛武; 董祥渊; 魏建巍; 谢世超; 占小猛; 张楠楠; 章海斌; 刘鑫
Original assignee: 平高集团有限公司; 国家电网有限公司; 国网安徽省电力有限公司超高压分公司
Priority date: 2020-12-08
Filing date: 2021-12-07
Publication date: 2022-06-16
Also published as: CN112670923B; CN112670923A

Abstract

A wall bushing, comprising a wall-through tube (2) fitting to a wall body, with an outdoor tube (3) and an indoor tube (4) abutting at two ends of the wall-through tube (2), wherein a bushing tube is provided with an end cover (5) on two ends thereof so as to seal an inner cavity of the bushing tube; a conductor (1) is located in the bushing tube; two middle shielding tubes (6) are provided, and are arranged at two ends of the wall-through tube (2) coaxially with the bushing tube and overhanging towards the outdoor tube (3) and the indoor tube (4) on the corresponding sides; and the conductor (1) passes through the middle shielding tubes (6) and has both ends thereof eccentrically arranged and located on an upper side of the axis of the bushing tube, such that the conductor (1), after flexural deformation, is located at a certain position in the middle shielding tubes (6) and coaxial with the corresponding middle shielding tube (6). When the conductor (1) is subjected to flexural deformation, the middle of the conductor (1) sags such that the portion thereof located at a certain position in the middle shielding tube (6) is coaxial with the corresponding middle shielding tube (5) so as to avoid the occurrence of discharge. In addition, there is no need to provide a supporting insulator in the bushing, which prevents the occurrence of flashover, so as to ensure that the wall bushing can run stably for a long time.

Description

a wall bushing

technical field

The invention relates to a wall-penetrating sleeve.

Background technique

UHV DC wall bushing is the key equipment in UHV DC project. Regarding its structure, such as a wall bushing disclosed in the Chinese invention patent with the application publication number CN110676779A and the application publication date of January 10, 2020 , the wall bushing mainly includes a bushing barrel and a conductor arranged in the bushing barrel, wherein the bushing barrel also includes a transition barrel (also called a wall barrel) for passing through the wall and a separate connection The left cylinder and the right cylinder at both ends of the transition cylinder, one of the left cylinder and the right cylinder is used to be arranged on the outside of the wall, and the other is used to be arranged on the inside of the wall. Both ends of the casing barrel are closed by setting end caps to form a sealed chamber capable of accommodating insulating media such as _SF6 gas, the conductor is arranged in the center of the casing barrel and both ends are connected to the center of the corresponding side end caps, In order to ensure that the electric field inside the wall bushing is uniform.

Because the wall bushing is generally arranged horizontally or inclined at 10° and has a long overall length, the conductor will be flexed and deformed under the action of gravity, and the distance between the outer peripheral surface of the conductor and the casing cylinder is not equal, increasing the casing The inhomogeneity of the internal electric field causes the concentration of the conductor field strength and increases the risk of discharge. In order to solve this technical problem, in the prior art, a supporting insulator is added between the casing barrel and the central conductor to support the conductor, so as to reduce the deflection and deformation of the conductor and keep the conductor and the casing barrel at a high level. However, during the long-term operation of the equipment, the electric charge will accumulate on the supporting insulator, and there is a hidden danger of flashover phenomenon, which reduces the reliability of the long-term operation of the wall bushing.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a wall-penetrating sleeve to solve the technical problem of low reliability during long-term operation of the wall-penetrating sleeve in the prior art.

The wall bushing of the present invention adopts the following technical solutions:

A wall-penetrating sleeve comprises a wall-penetrating cylinder for matching with the wall, the outdoor cylinder is butted at one end of the wall-penetrating cylinder, and is used to be arranged outside the wall, and the indoor cylinder is butted at the other side of the wall-penetrating cylinder. One end is used to be arranged on the inner side of the wall. The outdoor cylinder, the wall-penetrating cylinder and the indoor cylinder constitute the casing casing of the wall-penetrating casing. There are two end caps and are installed at both ends of the casing casing. In order to seal the inner cavity of the casing barrel, the conductor is located in the casing barrel, and the two ends are electrically connected to the end caps of the corresponding ends respectively. It also includes a middle shielding barrel, two of which are arranged coaxially with the casing barrel. The two ends of the wall-penetrating cylinder are overhanging toward the outdoor cylinder and the indoor cylinder on the corresponding side. The conductor passes through the middle shielding cylinder and both ends are eccentrically located on the upper side of the axis of the casing cylinder, so that the conductor After being flexed and deformed, a certain position in the intermediate shielding cylinder is coaxial with the corresponding intermediate shielding cylinder.

The beneficial effects are as follows: setting the middle shielding sleeve coaxial with the sleeve cylinder increases the electric field inside the sleeve, and at the same time reduces the electric field intensity at the position of the through-wall cylinder, which satisfies the air electric field criterion. The two ends are eccentric and are located on the upper side of the sleeve cylinder axis, so that the position of the conductor is raised. When the conductor is flexed and deformed, the middle part of the conductor sags so that the part located in the intermediate shielding cylinder can be at a certain position with the corresponding intermediate shielding The tube is coaxial, which minimizes the electric field strength of the conductor at this position and avoids the occurrence of discharge. At the same time, there is no need to set up support insulators in the casing, which also avoids the occurrence of flashover and ensures the long-term stable operation of the through-wall casing.

Further, the length of the outdoor cylinder is different from that of the indoor cylinder, and the connection position of the conductor end located in the longer cylinder on the end cover is higher than the connection position of the other end on the corresponding end cover.

The beneficial effect is that the connection position of the conductor end located in the long cylinder is raised, so that the part of the conductor located in the outdoor cylinder or the indoor cylinder can be easily connected to the corresponding intermediate shielding cylinder at a certain position after being flexed and deformed. coaxial.

Further, the length of the outdoor cylinder and the indoor cylinder are the same, and the connection positions of both ends of the conductor are at the same height.

The beneficial effect is that both ends of the conductor are of equal height, so that both the conductor located in the outdoor cylinder and the conductor located in the indoor cylinder can be coaxial with the corresponding intermediate shielding cylinder at a certain position after flexural deformation.

Further, the intermediate shielding cylinder has a retracted structure with a reduced diameter.

The beneficial effects are: the retraction of the middle shielding cylinder can reduce the electric field intensity outside the wall-penetrating sleeve close to the wall-penetrating cylinder body.

Further, the conductor is coaxial with the intermediate shielding cylinder at the smallest diameter of the intermediate shielding cylinder retraction structure.

The beneficial effects are as follows: the maximum electric field intensity in the wall-penetrating sleeve is the smallest diameter of the intermediate shielding cylinder, and the conductor is coaxially arranged with the intermediate shielding cylinder and the sleeve cylinder at this position, so that the electric field intensity can be minimized.

Further, the wall-penetrating sleeve further includes two end shielding cylinders, which are respectively disposed on the inner end surfaces of the two end caps and are arranged coaxially with the conductors.

The beneficial effect is that the end shielding cylinder can shield the end of the biased conductor.

Further, one end of the conductor is fixed on the corresponding end cap, and the other end is connected to the corresponding end cap through an active connection structure.

The beneficial effects are: the active connection at one end can make the conductor adapt to thermal expansion and cold contraction.

Further, the end shielding cylinder is a closed structure for receiving the debris generated during the operation of the wall bushing during the operation of the movable connection structure.

The beneficial effects are as follows: the metal debris generated during the operation of the wall bushing is accommodated in the end shielding cylinder with the closing structure, so as to prevent the debris from affecting the insulation performance of the wall bushing.

Further, the movable connection structure includes a sliding sleeve fixed on the inner wall surface of the end cover, and the conductor is inserted into the sliding sleeve in an axial sliding fit to realize the movable connection of the end on the corresponding end cover. The end shielding cylinder is outside the sliding sleeve.

The beneficial effects are: by fixing the sliding sleeve on the end cover and matching the conductor with the sliding sleeve inserting sleeve, the movable connection between the conductor and the end cover is simply and conveniently realized.

Description of drawings

1 is a schematic structural diagram of Embodiment 1 of the wall bushing in the present invention;

2 is a schematic structural diagram of the intermediate shielding cylinder in Embodiment 1 of the wall-penetrating sleeve of the present invention;

3 is a schematic structural diagram of the intermediate shielding cylinder in Embodiment 3 of the wall bushing in the present invention;

The names of the components corresponding to the corresponding reference numbers in the figure are:

1-conductor; 2-wall-penetrating cylinder; 3-outdoor cylinder; 4-indoor cylinder; 5-end cover; 6-intermediate shielding cylinder; 7-end shielding cylinder; 8-sliding sleeve; 9-large Diameter end; 10-Small diameter end; 11-Equal diameter section; 12-Conical section.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention, that is, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations.

Thus, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present invention.

It should be noted that relational terms such as the terms "first" and "second" that may appear in the specific implementation of the present invention are only used to distinguish one entity or operation from another entity or operation, and No such actual relationship or ordering between these entities or operations is necessarily required or implied. Moreover, the possible appearance of the terms "comprising", "comprising" or any other variation thereof is intended to encompass a non-exclusive inclusion such that a process, method, article or device comprising a list of elements includes not only those elements, but also no Other elements expressly listed, or which are also inherent to such a process, method, article or apparatus. Without further limitation, an element defined by the possible appearance of the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

In the description of the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected" and "connected" that may appear should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection, Or integrally connected; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or the internal communication between the two components. Those skilled in the art can understand the specific meanings of the above terms in the present invention through specific situations.

In the description of the present invention, unless otherwise expressly specified and limited, the term "provided" that may appear should be understood in a broad sense. For example, the object "provided with" may be a part of the body or a separate body from the body. Arranged and connected on the body, the connection can be a detachable connection or a non-detachable connection. Those skilled in the art can understand the specific meanings of the above terms in the present invention through specific situations.

The present invention will be further described in detail below in conjunction with the embodiments.

Embodiment 1 of the wall bushing in the present invention is introduced by taking the application to UHV DC engineering as an example in this embodiment:

As shown in FIG. 1 , the wall bushing includes a bushing barrel and a conductor 1 arranged in the bushing barrel.

The casing barrel includes a wall-penetrating barrel 2 located in the middle, the wall-penetrating barrel 2 is a metal pipe body, and the wall-penetrating casing is matched with the wall through the wall-penetrating barrel 2 . The left end of the wall-penetrating cylinder 2 is connected to the outdoor cylinder 3 through a flange structure, and the right end is connected to the indoor cylinder 4 through a flange structure. In this embodiment, the outdoor cylinder 3 and the indoor cylinder 4 are both hollow composite insulators. The through-wall casing 2, the outdoor casing 3 and the indoor casing 4 constitute the casing casing of the wall casing. The conductor 1 is arranged in the casing barrel of the wall bushing to realize the transmission of current.

In order to fill the insulating medium in the casing barrel, both ends of the casing barrel are also provided with end caps 5, and the inner cavity of the casing barrel is sealed into a closed space by the end covers 5 at both ends. Both ends of the conductor 1 are conductively connected to the end cover 5 on the corresponding side, so as to realize the arrangement of the conductor 1 in the casing barrel. In this embodiment, the insulating medium filled in the wall bushing is SF ₆ gas. In other embodiments, the insulating medium in the wall bushing may also be insulating oil.

In order to prevent the occurrence of discharge inside the wall bushing, the wall bushing further includes two middle shielding cylinders 6 and two end shielding cylinders 7 arranged in the casing barrel, wherein, in this embodiment, the middle shielding cylinder 6 It is a tapered structure, taking the middle shielding cylinder 6 on the left side as an example, as shown in Figures 1 and 2, the large diameter end 9 of the middle shielding cylinder 6 has an outer flange. Between the flange matching structure of the cylinder body 2 and the outdoor cylinder body 3, the installation of the intermediate shielding cylinder 6 in the casing cylinder can be realized, and the outer flange of the intermediate shielding cylinder 6 can be set with the wall-penetrating cylinder body 2 and the outdoor cylinder body 3. The corresponding bolt perforation of the flange matching structure, of course, the bolt perforation may not be provided and only fixed by clamping.

The intermediate shielding cylinder 6 is coaxial with the casing cylinder, and the small diameter end 10 of the intermediate shielding cylinder 6 is overhanging toward the outdoor cylinder 3 . The structure of the other intermediate shielding cylinder 6 is the same as that, and is overhanging toward the interior of the indoor cylinder 4 . The tapered structure makes the middle shielding cylinder 6 shrink inward to have a small diameter structure, which can reduce the electric field intensity outside the wall-penetrating sleeve close to the wall-penetrating area. This can ensure that the electric field intensity inside the wall bushing will not be too large.

The reason why the intermediate shielding cylinder 6 is provided is because the electric field strength criterion of SF ₆ is higher than that of air. If the intermediate shielding cylinder 6 is not provided, the electric field strength inside the wall bushing is lower, and the electric field in the area closer to the wall penetration cylinder 2 is relatively low. The intensity exceeds the air electric field criterion. After the middle shielding cylinder 6 is installed, the electric field intensity inside the casing can be increased, and the electric field criterion of SF ₆ is higher, which meets the needs of use. The electric field intensity near the wall-penetrating cylinder 2 decreases, which satisfies the air electric field criterion.

As shown in FIG. 1 , the two end shielding cylinders 7 are respectively arranged on the inner wall surfaces of the corresponding side end covers 5 and cantilever toward the inside of the casing cylinder, and are arranged coaxially with the ends of the conductors 1 , so that the conductors 1 end shielded. Different from the middle shielding cylinder 6, the end shielding cylinder 7 is turned inward to form a closed structure, so that the end shielding cylinder 7 has a storage function.

In order to prevent the conductor 1 from being flexed and deformed and unable to be coaxial with the intermediate shielding cylinder 6, the conductor 1 is eccentrically arranged in the sleeve cylinder. Specifically, the end of the conductor 1 is connected to the upper center of the end cover 5, so that the The end of the conductor 1 is located on the upper side of the axis of the casing cylinder. After the conductor 1 is flexed and sags, the part corresponding to the smallest diameter of the conductor 1 and the intermediate shielding cylinder 6 can be coaxial with the intermediate shielding cylinder 6 . The maximum electric field strength in the casing is at the minimum diameter of the intermediate shielding cylinder 6. At this position, the conductor 1 is coaxial with the intermediate shielding cylinder 6 and the casing cylinder, so that the electric field strength at this position can be minimized. The provision of the end shielding cylinder 7 can prevent the eccentric arrangement of the end of the conductor 1 from causing an excessive electric field at the end of the sleeve. The end shielding cylinder 7 has the same potential as the conductor 1, the middle shielding cylinder 6 has the same potential as the wall-penetrating cylinder 2, and the shielding cylinder changes the potential distribution, thereby affecting the electric field strength inside and outside the casing.

In this embodiment, the left end of the conductor 1 is connected to the left end cover 5 in a fixed and conductive manner, and the right end and the right end cover 5 are electrically connected through an active connection structure. Specifically, the inner wall surface of the end cover 5 on the right side of the wall bushing A sliding sleeve 8 is fixed, the axis of the sliding sleeve 8 is parallel to the axis of the casing cylinder, and the right end of the conductor 1 is axially slidably inserted into the sliding sleeve 8 to realize the active connection between the end and the end cover 5, and enable the conductor 1 to be able to To adapt to thermal expansion and cold contraction, the end shielding cylinder cover of this end is outside the sliding sleeve 8, which can ensure reliable shielding of this end. In other embodiments, both ends of the conductor may be connected to the corresponding end caps through a fixed connection structure. Of course, both ends of the conductor may be connected to the corresponding end caps through a movable connection structure. The movable connection structure may also be a tension spring. Specifically, One end of the tension spring is connected to the end of the conductor, and the other end is fixed on the end cover.

Since one end of the conductor 1 is movably connected to the corresponding side end cover, vibration, friction and metal debris may be generated during transportation and use. The end shielding cylinder with a closing structure can accommodate the generated metal debris and avoid metal debris It falls on the inner wall of the hollow composite insulator and affects the shielding and insulation performance of the wall bushing.

In this embodiment, the length of the outdoor cylinder 3 is greater than the length of the indoor cylinder 4. Therefore, the fixing position of the conductor 1 on the left end cover 5 is higher than its fixing position on the right end cover 5 to ensure The portion of the conductor 1 corresponding to the smallest diameter of the left-side intermediate shielding cylinder 6 is coaxial with the intermediate shielding cylinder 6 . In other embodiments, it is also possible to make the length of the indoor cylinder longer than the length of the outdoor cylinder according to the actual use situation. In this case, the connection position of the right end of the conductor on the right end cap is higher than that of the left end on the left end cap Of course, when the length of the outdoor cylinder and the indoor cylinder are the same, the heights of both ends of the conductor should be the same and higher than the axis of the casing cylinder.

The second embodiment of the through-wall bushing in the present invention is different from the first embodiment in that the end shielding cylinder is provided in the first embodiment. In this embodiment, since the electric field at the end of the conductor is relatively uniform, The end shielding cylinder is no longer set in the wall bushing. In order to prevent the metal debris generated at the end of the conductor from affecting the insulation performance of the wall bushing, a storage device specially used to receive metal debris is installed on the inner wall of the end cover. The storage device may not have a shielding function, such as an insulating storage box.

The third embodiment of the wall-penetrating sleeve in the present invention is different from the first embodiment in that, in the first embodiment, the intermediate shielding cylinder has a conical structure. In this embodiment, the structure of the intermediate shielding cylinder is as follows: As shown in FIG. 3 , one end of the intermediate shielding cylinder used to cooperate with the wall-penetrating cylinder is an equal diameter section 11, a section of the overhanging end is a conical section 12, and the edge of the conical section 12 is everted, so that the intermediate shielding cylinder has Trail structure.

The fourth embodiment of the wall-penetrating sleeve in the present invention is different from the first embodiment in that in the first embodiment, in order to have a better shielding effect, the middle shielding cylinder has a small diameter structure. , On the premise that the shielding requirements are met, the middle shielding cylinder may not have a small diameter section, and the part of the conductor located in the middle shielding cylinder may be coaxial with the middle shielding cylinder.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. The scope of patent protection of the present invention is subject to the claims. Any equivalent structural changes made by using the description and accompanying drawings of the present invention, Similarly, all should be included in the protection scope of the present invention.

Claims

A wall bushing, comprising:

Through the wall cylinder, used to cooperate with the wall;

The outdoor cylinder is butted at one end of the wall-penetrating cylinder to be arranged outside the wall;

The indoor cylinder is connected to the other end of the wall-penetrating cylinder and is used to be arranged on the inner side of the wall;

The outdoor cylinder, the through-wall cylinder and the indoor cylinder constitute the casing cylinder of the through-wall casing;

There are two end caps installed on both ends of the casing barrel to seal the inner cavity of the casing barrel;

The conductor is located in the casing barrel, and the two ends are electrically connected to the end caps of the corresponding ends respectively;

It is characterized in that it also includes:

There are two intermediate shielding cylinders, which are arranged at both ends of the wall-penetrating cylinder coaxially with the casing cylinder, and cantilever toward the outdoor cylinder and the indoor cylinder on the corresponding side;

The conductor passes through the intermediate shielding cylinder and both ends are eccentrically arranged on the upper side of the casing cylinder axis, so that after the conductor is flexed and deformed, a certain position in the intermediate shielding cylinder is coaxial with the corresponding intermediate shielding cylinder.
The wall bushing according to claim 1, wherein the length of the outdoor cylinder is different from that of the indoor cylinder, and the connection position of the end of the conductor located in the longer cylinder on the end cover is higher than that of the other end on the corresponding end connection location on the cover.
The wall bushing according to claim 1, wherein the outdoor cylinder and the indoor cylinder have the same length, and the connection positions of both ends of the conductor are at the same height.
The wall bushing according to any one of claims 1-3, wherein the intermediate shielding cylinder has a retracted structure with a reduced diameter.
The wall bushing according to claim 4, wherein the conductor is coaxial with the intermediate shielding cylinder at the smallest diameter of the intermediate shielding cylinder retraction structure.
The wall-penetrating sleeve according to any one of claims 1-3, wherein the wall-penetrating sleeve further comprises two end shielding cylinders, and the two end shielding cylinders are respectively arranged on the inner end faces of the two end caps on and coaxial with the conductor.
The wall bushing according to claim 6, wherein one end of the conductor is fixed on the corresponding end cover, and the other end is connected to the corresponding end cover through an active connection structure.
The wall bushing according to claim 7, wherein the end shielding cylinder is a closed structure for receiving debris generated during the operation of the wall bushing by the movable connection structure.
The wall bushing according to claim 7, wherein the movable connection structure comprises a sliding sleeve fixed on the inner wall surface of the end cover, and the conductor is inserted into the sliding sleeve in an axial sliding fit to realize that the end is in the sliding sleeve. Corresponding to the movable connection on the end cover, the end shielding cylinder on the end cover is covered outside the sliding sleeve.