CN213546021U

CN213546021U - High-voltage bushing

Info

Publication number: CN213546021U
Application number: CN201790001831.8U
Authority: CN
Inventors: C.保罗; S.森多布里; E.恩格尔斯; A.兰根斯; J.蒂策
Original assignee: Siemens AG
Current assignee: Huishipu High Voltage Electrical Co ltd
Priority date: 2017-12-12
Filing date: 2017-12-12
Publication date: 2021-06-25
Anticipated expiration: 2027-12-12
Also published as: EP3711071A1; WO2019114933A1; EP3711071B1

Abstract

The present invention relates to a high voltage bushing (1) having an inner conductor (2) and an insulator (5), the inner conductor extending in a longitudinal direction between a first and a second high voltage connection (3, 4) of the high voltage bushing; an insulator at least partially surrounds the inner conductor, wherein the insulator comprises control inserts (27a-e) for controlling the electric field in the area (26) of the control inserts, and the control inserts are separated from each other by an insulating layer. The utility model is characterized in that at least one electrode element (12a) is electrically connected with at least one of the control inserts and is led out from the regional axial direction of the control insert.

Description

High-voltage bushing

Technical Field

The present invention relates to a high voltage bushing having an inner conductor and an insulator, the inner conductor extending in a longitudinal direction between a first and a second high voltage connection of the high voltage bushing; the insulator at least partially surrounds the inner conductor, wherein the insulator comprises control inserts arranged in the region of the control inserts, which control inserts are separated from one another by an insulating layer, and wherein the control inserts are suitably arranged concentrically around the inner conductor.

Background

In general, the task of such high-voltage bushings is to insulate the inner conductor of the high-voltage bushing, which is located in the high-voltage potential during operation of the high-voltage bushing, from the environment located in the ground potential, for example the wall of the high-voltage arrangement. The voltage difference to ground is here, for example, greater than 300kV, in particular greater than 600 kV. For this purpose, the inner conductor is guided through the insulator. The conductive control insert embedded in the insulator serves to control the electric field, thereby achieving a homogenization of the electrical stress both radially and axially inside and outside the insulator. In this way, significant electrical stresses on the surface and in the insulation can be avoided or at least reduced.

Such a high voltage bushing is known from WO 2015/172806a 1. The insulating layer of the known high voltage bushing comprises a resin-impregnated crepe paper.

The control insert region is the region of the insulator where the control insert is disposed. Typically, the control insert region extends along a portion of the inner conductor. A high-voltage connection is generally understood to be a suitably configured connection point suitable for connection to a further current line.

It is generally applicable that the length of the axial control line of the high-voltage bushing, i.e. in particular the insulator, is dependent on the voltage to be insulated. The higher the voltage to be insulated, the longer the insulator has to be designed in order to achieve a uniform, permissible electrical loading in the longitudinal direction of the high-voltage bushing. Therefore, the material cost increases with the voltage to be insulated. Corresponding production facilities and installation halls must also be provided in order to be able to build the necessary structural lengths. Furthermore, large structural lengths require expensive adjustments with respect to mechanical, for example seismic, induced stresses.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the present invention is to provide a high-voltage bushing which is as inexpensive and light as possible.

In this respect, the object is achieved by a high-voltage bushing having:

an inner conductor extending in a longitudinal direction between a first and a second high voltage connection of a high voltage bushing,

the invention provides that at least one electrode element is electrically connected to at least one of the control inserts and is guided axially out of the region of the control insert.

According to a further development of the invention, it is provided that the at least one first electrode element is at least partially cylindrical and/or conical and extends in the longitudinal direction of the high voltage bushing and concentrically with respect to the inner conductor.

According to a further development of the invention, it is provided that the at least one first electrode element has a rounded corner at its end facing away from the control insert region in order to avoid an excessively high electric field strength.

According to a further development of the invention, it is provided that a second electrode element is provided, wherein the first electrode element and the second electrode element are arranged opposite one another at both axial ends of the control insert region, wherein the first electrode element and the second electrode element extend concentrically in the longitudinal direction of the high-voltage bushing and relative to the inner conductor.

According to a further development of the invention, it is provided that the high-voltage bushing is a wall bushing, wherein the first and second high-voltage contacts are external contacts for connection to a respective one of the high-voltage conductors.

According to a further embodiment of the invention, it is provided that the insulating body comprises two concentric windings and that the first and second electrode elements are guided out of the control insert region at the connection point of the windings.

According to a further development of the invention, it is provided that the high-voltage bushing has a plug section which is provided for inserting the high-voltage bushing into a device connection part of an electrical device, wherein the control insert extends into the plug section.

According to a further embodiment of the invention, it is provided that the insulating body further comprises a hardened resin.

According to a further embodiment of the invention, the insulating body serves as a mechanical support element for the first electrode element and the second electrode element.

According to a further development of the invention, it is provided that the high-voltage bushing has an outer housing which at least partially surrounds the insulator on the outside, wherein the outer housing is at least partially made of a composite material, wherein a secondary insulation is arranged between the outer housing and the insulator.

According to a further development of the invention, it is provided that the secondary insulation is a gaseous secondary insulation.

The electrically conductive, low-ohmic electrode elements are thus electrically connected to the defined control insert of the electric field control of the insulating body. The electric field control may be capacitive and/or resistive, for example. The electric potential can thus be moved axially into the desired position by means of the electrode element. An equalization of the electrical load of the high-voltage bushing and its surroundings can thus advantageously be achieved. An as cylindrical as possible electric field leading to the inner conductor is generated within the electrode element and outside the control insert region. The electric field escapes as a result of the potential shift firstly at the end of the electrode element axially opposite the control insert region. The connection of the at least one electrode element to the control insert can be realized, for example, by means of suitable potential taps (patent application). The potential tapping can be realized using suitable, electrically conductive components, for example copper strips. The mechanical fixing of the electrode element can be provided expediently in the case of the use of an insulator.

According to the utility model discloses a high-tension bushing can be used for among static electric field (DC), quasi-static electric field (AC) and the impact process.

An advantage of the high voltage bushing according to the invention is that the control insert area of the insulator can be shortened axially by using the electrode element. In this way, for example, the previously described disadvantages, which arise, for example, on account of the large weight of the insulator and thus of the high-voltage bushing, can be avoided. Additionally, new applications may be realized with the high voltage bushing according to the invention, for example in a voltage range above 1000 kV.

Preferably, the electrode element is at least partly cylindrical, conical or the like and extends in the longitudinal direction of the high voltage bushing and concentrically with respect to the inner conductor. A particularly advantageous electric field distribution can be achieved with this design of the electrode element.

The electrode element preferably has rounded corners at its end facing away from the control insert region in order to avoid an excessively high electric field strength. By means of the rounded corners, an unfavourable too high electric field strength at the ends of the electrode elements can be avoided. In connection therewith, each rounded profile is suitable as a rounding corner, for example in the sense of a Rogowski profile known per se to the person skilled in the art.

According to an embodiment of the invention, a further electrode element is provided, wherein two electrode elements are arranged opposite each other on or in the region of the two axial ends of the control insert region, wherein the two electrode elements extend concentrically in the longitudinal direction of the high-voltage bushing and relative to the inner conductor. In this way, the insulator or control insert region can be embodied as shortened at both ends. This embodiment is particularly advantageous when the high voltage bushing is a wall bushing, wherein the two high voltage connectors are external connectors for connection with a respective one of the high voltage conductors. The external joint may for example be an open air joint. Both electrode elements may be constructed similarly. In particular, the further electrode element is likewise guided axially out of the region of the control insert of the insulating body. The high voltage conductor may be, for example, a part of an open-air line or a conductor rail or a connection of both.

The insulator typically comprises a single winding body formed by a control insert and an insulating layer wound on a winding core. According to an embodiment of the invention, the insulator comprises two concentric windings. The electrode element is guided out of the control insert region at the connection point of the winding body. The two windings can be nested with one another, for example, during the production of the high-voltage bushing. The electrode elements may for example be mechanically fixed in position between the windings.

The high voltage bushing may be implemented as a pluggable high voltage bushing. For this purpose, the high-voltage bushing has a plug section which is provided for inserting the high-voltage bushing into a device connection part of the electrical device, wherein the control insert extends into the plug section. The electrical device may be, for example, a high voltage transformer. The plug section of the high-voltage bushing and the device connection part are designed such that a reliable electrical contact can be established between the inner conductor of the high-voltage bushing and the device connection part, wherein the device connection part is electrically connected to a further element of the electrical device, for example a transformer winding arranged in the housing. At the same time, the connection at the boundary surface between the device connection part and the plug section is sufficiently dielectrically strengthened, so that operation at high pressure levels is possible. The control insert extends into the plug section of the high-voltage bushing. In this way, the electric field can also be effectively controlled in the plug-in region, so that the sensitive region of the connection between the device connection part and the high-voltage bushing has better electrical properties.

The insulator also preferably comprises a hardened resin. The high-voltage bushing may be impregnated with a curable resin, for example, during the manufacturing process, for example, after winding the insulation layer. After the resin has hardened, an insulator with better electrical insulation can thus be obtained. The insulator with resin is present here as a main insulator in the form of a compact block. According to this embodiment variant, the insulator advantageously provides a mechanical support for the inner conductor of the high-voltage bushing as a fixed block. In this way, bending of the inner conductor due to its own weight can be avoided or reduced. The inner conductor supported by the insulating body can thus always be kept at a defined radial distance from the electrode element along the length of the inner conductor, so that the electrical properties are not adversely affected by possible bending of the inner conductor. In a similar manner, the insulator also serves as a mechanical support element for the electrode element.

According to a further embodiment of the invention, the high voltage bushing has an outer shell which at least partly surrounds the insulator on the outside, wherein the outer shell is at least partly composed of a composite material, wherein a secondary insulation is provided between the outer shell and the insulator. The secondary insulation preferably comprises an insulating gas. A suitable insulating gas is, for example, SF₆Or air at high pressure. The composite material may be, for example, a fiber reinforced plastic. The housing element is preferably made of glass fiber-reinforced plastic, which ensures a particularly high stability. According to a variant of the invention, the housing element can be a tube made of glass fiber-reinforced plastic. Furthermore, an outer insulator is attached to the tubular housing element, the outer insulator comprising, for example, a tubular silicone shield.

The insulating layer of the insulator may comprise paper. But the insulating layer may also be made of plastic. The insulating layer can comprise, for example, a plastic nonwoven material, which is preferably formed from so-called endless threads.

Drawings

The invention will be further elucidated hereinafter on the basis of the embodiments shown in fig. 1 to 3.

Figure 1 shows a first embodiment of a high voltage bushing according to the invention in a schematic cross-sectional view;

figure 2 shows a second embodiment of a high voltage bushing according to the invention in a schematic cross-sectional view;

figure 3 shows an enlarged partial view of the high voltage bushing of figures 1 and 2 in a schematic cross-sectional view.

Detailed Description

Fig. 1 shows a high voltage bushing 1. The high voltage bushing 1 is designed as a wall bushing. High voltage bushings are used for guiding a high voltage conductor, which in operation is located at a high voltage, for example over 500kV, through a wall or a wall. For example, this relates to a wall of a high-voltage direct-current transmission hall.

The high voltage bushing 1 comprises an inner conductor 2, which may be connected with a high voltage conductor (which is not shown in detail in fig. 1) not only at a first axial end 3, but also at a second axial end 4 of the high voltage bushing 1. The high-voltage conductor can be part of an open-air line or a transmission line leading to a transformer winding or a valve block, for example.

The inner conductor 2 is partially surrounded by a spindle-shaped insulator 5. The insulator 5 comprises control inserts 27a-e shown in detail in fig. 3. The control inserts 27a-e are arranged concentrically around the inner conductor 2 (generally understood to be concentric depending on the control insert which is arranged almost concentrically in the manufacturing place). The control insert is used for capacitive and/or resistive electric field control. The control inserts are separated from each other by an insulating layer, which comprises paper or plastic, for example a plastic-nonwoven material. An insulating layer is wound on the inner conductor 2. Typically, the insulation layer may also be wound on a separate retained or removable bobbin. The insulator 5 is immersed in the resin after the winding of the insulation layer and hardened, whereby the insulator forms a compact block which mechanically supports the inner conductor 2. The insulator 5 is often also referred to as a main insulator. The region of the insulator 5 in which the control insert is arranged is referred to as the control insert region 26 (see fig. 3).

The high voltage bushing 1 further comprises a fixation flange 6 for fixing the high voltage bushing to a wall portion or wall at ground potential. The fastening flange 6 acts mechanically, for example by means of a clamping connection, directly on the insulating body 5.

The high voltage bushing 1 is equipped with a housing 7. The housing 7 can be formed, for example, at least partially from a composite material, for example from a fiber-reinforced plastic. In the intermediate space 8 between the housing 7 and the insulator 5, a secondary insulation 9 is arranged, which is formed, for example, by an insulating gas, such as SF₆And (4) forming. An outer layer in the form of a silicone shield 13 is arranged outside the housing 7.

At both axial ends 3, 4 of the high voltage bushing 1 there are two shielding

electrodes

10 and 11 for further shielding the electric field.

The high voltage bushing comprises a first electrode element 12a and a second electrode element 12 b. The two

electrode elements

12a and 12b are cylindrical and arranged concentrically with respect to the inner conductor 2. The two

electrode elements

12a or 12b are electrically connected to one of the control inserts and are mechanically connected to the insulating body. Each

electrode element

12a or 12b is guided axially out of the insulating body 5. The first electrode element 12a is guided out of the insulating body 5 in the direction of the first axial end 3 and the second electrode element 12b in the direction of the second axial end 4. Each of the two

electrode elements

12a or 12b extends in particular axially beyond the conically

tapered end

5a or 5b of the insulator 5. The insulator 5 forms a mechanical support for the electrode elements 12a, b.

Each of the two

electrode elements

12a or 12b has a rounded

corner

14a or 14b on one of its ends, the rounded corner serving to avoid an excessively high electric field strength.

Fig. 2 shows a further high voltage bushing 15, which further high voltage bushing 15 is designed as a device bushing. The high voltage bushing 1 and the high voltage bushing 15 parts of figure 1 are similarly constructed. To avoid repetition, only their differences will be discussed later. Identical and similar elements in fig. 1 and 2 are provided with the same reference numerals here.

In contrast to the high-voltage bushing 1 of fig. 1, the high-voltage bushing 15 comprises, in addition to the first axial end 3, a device-side end 16, which in this case is also referred to as an open end. The inner conductor 2 is guided out of the high-voltage bushing 15 at a device-side end 16 and is intended for connection to a conductor in the interior of an electrical device, for example a high-voltage transformer. The fastening flange 18 serves to fasten the high-voltage bushing 15 to a device housing of an electrical device, which is illustrated in fig. 2 by means of a dashed line 17.

The high-voltage bushing 15 has an electrode element 12a arranged on the weather side.

Fig. 3 shows an enlarged fragment of the high voltage bushing 20. In the segment shown in fig. 3, the high voltage bushing 20 is implemented identically to the two high voltage bushings 1 or 15 shown previously in fig. 1 and 2. The illustration of fig. 3 may thus also be used to illustrate a corresponding segment of the high voltage bushing 1 or 15. For the sake of clarity, identical or similar components and elements of the

high voltage bushings

20, 1 and 15 in fig. 1 to 3 are provided with the same reference numerals.

The insulator 5 includes conductive control inserts 27 a-e. It is to be noted here that the number of control inserts shown in fig. 3 is an example, but can in principle be arbitrary and adapted to the respective application. The control inserts are arranged concentrically with respect to each other with respect to the inner conductor 2. The control inserts are separated from one another by insulating layers 28a-d, wherein the insulating layers are wound on the inner conductor 2 (or on a winding core surrounding the inner conductor) to form a wound body 22, which is impregnated with resin and hardened during the production process. The control inserts 27a-e are each of different lengths, wherein the length of the control inserts decreases with the radial distance from the inner conductor 2. Fig. 3 shows in a line the boundary of the control insert region 26 within the winding body 22, i.e. the boundary to which the control insert arrangement in the winding body 22 of this region reaches or extends axially.

The electrode element 12a is arranged with one end at a connection point 24 with the insulator 5. The electrode element 12a is electrically connected to the control insert 27b by means of a potential tap 25. The electrode element 12a is furthermore mechanically held in position by the resin body of the insulator 5.

Claims

1. A high voltage bushing (1) having:

-an inner conductor (2) extending in a longitudinal direction between a first and a second high voltage connection (3, 4) of a high voltage bushing (1),

-an insulation body (5) at least partially surrounding the inner conductor (2), wherein the insulation body (5) comprises control inserts (27a-e) controlling the electric field in a control insert area (26), the control inserts being separated from each other by insulation layers (28a-d),

characterized by at least one first electrode element (12a) which is electrically connected to at least one of the control inserts and which leads axially out of the area (26) of the control insert.

2. The high voltage bushing (1) according to claim 1, wherein the at least one first electrode element (12a) is at least partly cylindrical and/or tapered and extends concentrically in the longitudinal direction of the high voltage bushing (1) and with respect to the inner conductor (2).

3. The high voltage bushing (1) as claimed in claim 2, wherein the at least one first electrode element (12a) has rounded corners (14a, 14b) on its end facing away from the control insert region (26) for avoiding an excessively high electric field strength.

4. The high voltage bushing (1) according to claim 1 or 2, wherein a second electrode element (12b) is provided, wherein the first electrode element (12a) and the second electrode element (12b) are arranged opposite each other on both axial ends of the control insert region (26), wherein the first electrode element (12a) and the second electrode element (12b) extend in the longitudinal direction of the high voltage bushing (1) and concentrically with respect to the inner conductor (2).

5. The high voltage bushing (1) according to claim 4, wherein said high voltage bushing (1) is a wall bushing, wherein said first and second high voltage contacts (3, 4) are external contacts for connection with a respective one of the high voltage conductors.

6. The high voltage bushing (1) according to claim 4, wherein the insulator (5) comprises two concentric windings (22a, 22b) and the first electrode element (12a) and the second electrode element (12b) are led out of the control insert region (26) at a connection location (24) of the windings (22a, 22 b).

7. The high voltage bushing (1) according to claim 1 or 2, wherein the high voltage bushing has a plug section which is provided for inserting the high voltage bushing into a device connection part of an electrical device, wherein the control insert extends into the plug section.

8. The high voltage bushing (1) as claimed in claim 1 or 2, wherein said insulator (5) further comprises a hardened resin.

9. The high voltage bushing (1) according to claim 8, wherein the insulator (5) serves as a mechanical support element for the first electrode element (12a) and the second electrode element (12 b).

10. The high voltage bushing (1) as claimed in claim 1 or 2, wherein the high voltage bushing (1) has an outer shell (7) which at least partially surrounds the insulator (5) externally, wherein the outer shell (7) is at least partially composed of a composite material, wherein a secondary insulation (9) is provided between the outer shell (7) and the insulator (5).

11. The high voltage bushing (1) as claimed in claim 10, wherein said secondary insulation (9) is a gaseous secondary insulation.