HIGH-VOLTAGE GUARD, ELECTRICAL DEVICE WITH HIGH-VOLTAGE GUARD AND METHOD FOR MANUFACTURING THE ELECTRICAL DEVICE

Description

[0001] The invention relates to a high-voltage feedthrough with a mounting flange for attaching the high-voltage feedthrough to a wall.

[0002] In general, the purpose of such a high-voltage bushing is to isolate a high-voltage line carrying a current from its surroundings, which are essentially at ground potential. The housing is typically a high-voltage device enclosure or a wall within a high-voltage installation. An inner conductor of the bushing forms part of, or is integrated into, the current-carrying conductor.

[0003] A high-voltage bushing of the type mentioned above is known from DE 10 2007 022 641 A1. This patent discloses an electrical device in the form of a transformer, the housing of which has a device connection section into which a high-voltage bushing can be plugged for connecting the transformer to a high-voltage network. By using such a pluggable high-voltage bushing, it is possible to assemble and commission the transformer with the high-voltage bushing with minimal assembly effort. The plug-in section of the high-voltage bushing and the device connection section are designed such that a reliable electrical contact can be established between the inner conductor of the high-voltage bushing and the device connection section, with the device connection section being electrically connected to other elements of the electrical device, such as a transformer active part arranged within the housing.At the same time, the connection at the interfaces between the device connection part and the plug section is sufficiently dielectrically reinforced to allow operation at high voltage levels. The insulating body is typically constructed by wrapping layers of paper insulation around the inner conductor. The high-voltage bushing is attached to the wall of the transformer housing by a mounting flange, usually a single piece, which is essentially fixed relative to the bushing housing.

[0004] From DE 10 2013 011 981 B3, a device for attaching a connection device to a switchgear or a transformer is known, wherein, for example, a cable plug with an attached high-voltage cable can be connected to the switchgear or the transformer by means of the connection device. The known device comprises a fastening element and a locking element rotatable about a longitudinal axis of the device relative to the fastening element, by means of which the cable plug, the plug part of a bushing, or any other electrical device interacting with the device connection part can be locked with respect to its rotational position.

[0005] Document US 3 073 891 A reveals a rotatable feedthrough.

[0006] Document US 2 889 396 A discloses a constructive fastening arrangement for the adjustable positioning and fastening of a bushing on a support.

[0007] Document EP 3 142 207 A1 discloses a fastening device for attaching a cable connector to a bracket.

[0008] Document FR 2 865 859 A1 discloses a device having a fixed flange welded to a wall of a cover of a device around an opening.

[0009] The object of the invention is to propose a high-voltage bushing of the above type that is as versatile as possible in its use.

[0010] The problem is solved according to the invention by a high-voltage bushing according to claim 1. The mounting flange comprises a retaining part and a moving part, wherein the moving part is rotatably mounted relative to the retaining part with respect to a longitudinal direction of the high-voltage bushing. Accordingly, the mounting flange is formed in at least two parts. The retaining part can, for example, be fixed to a housing of the high-voltage bushing or directly to an active part of the high-voltage bushing. In contrast, the moving part is movably mounted. The movement of the moving part relative to the retaining part is, except for any manufacturing tolerances, limited to a rotational movement with respect to an axis, the longitudinal axis of the high-voltage bushing. The longitudinal axis is usually defined by the path of the inner conductor.The high-voltage bushing according to the invention has the advantage that it can be easily mounted on a high-voltage device or its casing, even in higher voltage ranges, for example, above 500 kV. It can also be designed as a pluggable connection and used in conjunction with a device connection unit. As is known, a high-voltage bushing designed for high voltage ranges above 500 kV is particularly long and heavy. If the high-voltage bushing is designed for voltages above 500 kV, its length can exceed 5 m, and in particular, more than 10 m. The weight of such a high-voltage bushing can, accordingly, amount to several tons in such cases. To commence operation, the high-voltage bushing must be mounted on the casing or plugged into a provided device connection unit.A crane is typically used to insert the high-voltage bushing into a receptacle in the wall or the device connection part. Fasteners are used to secure the bushing to the mounting flange and to the wall or device connection part; these fasteners must be aligned with each other in terms of their rotational position. For example, threaded holes on the mounting flange are aligned with corresponding pins or screws on the wall, or vice versa. However, once the high-voltage bushing is inserted into the receptacle, the portion of the bushing inserted into the receptacle cannot be rotated due to friction between it and the receptacle. The alignment of the fasteners is only possible using the movable part of the mounting flange.In a particularly simple version, the fastening means for attaching the high-voltage bushing to the device connection part can be provided on the movable part of the mounting flange. A further advantage of the high-voltage bushing according to the invention is that, regardless of the wall structure or the device connection part, it can be aligned during assembly as described above, solely by means of the partially movable mounting flange.

[0011] Preferably, the retaining element is fixed relative to an outer housing of the high-voltage feedthrough, i.e., essentially immobile. This further simplifies the design and mounting of the high-voltage feedthrough, particularly when the retaining element is a single piece. However, the retaining element can also be multi-part. For example, the retaining element can also include movable parts. For instance, the retaining element can be tiltable relative to the outer housing, i.e., rotatable about an axis perpendicular to the longitudinal axis.

[0012] According to the invention, the moving part is a rotating ring arranged concentrically around the holding part. In this embodiment, aligning the moving part during the installation of the high-voltage bushing is particularly easy. The installer can rotate the relatively light moving part around the relatively heavy rest of the high-voltage bushing.

[0013] The moving ring has an extension on its inner side that engages in an outer guide groove of the retaining part. This ensures that the movement of the two parts relative to each other is essentially limited to rotation around the longitudinal axis. Tilting or jamming of the moving part and the retaining part is impossible. The guide groove is conveniently located radially on the outer edge of the retaining part.

[0014] The retaining element is formed in at least two parts, with a first and a second annular element. The first element has a first outer cut, and the second element has a second outer cut. When the elements are assembled, the two cuts together form the guide groove. This allows for a particularly simple and cost-effective manufacturing process for the mounting flange, as the guide groove does not need to be machined into a single piece.

[0015] A pluggable high-voltage bushing is particularly preferred. In this embodiment, the high-voltage bushing comprises an inner conductor extending longitudinally between a high-voltage terminal and a pluggable section of the bushing. The pluggable section is designed for insertion of the high-voltage bushing into a device terminal of an electrical device and has an outer coating of a flexible insulating material. The advantages of the invention are particularly evident in this embodiment. Due to the outer coating, the frictional connection between the pluggable section and the device terminal is exceptionally strong, so that in this case, the movable design of the mounting flange is essential for the practical use of a high-voltage bushing, especially in the high-voltage range above 500 kV.

[0016] Preferably, the insulating body of the high-voltage bushing comprises field-controlling control inserts separated from one another by insulating layers, the control inserts being arranged concentrically around the inner conductor. The control inserts can, for example, be configured to provide capacitive field control of the electric field within the insulating body. The control inserts are arranged concentrically around the inner conductor, except for manufacturing tolerances. Thus, in a cross-section through the insulating body, the control inserts form concentric or nearly concentric circles, or nearly closed circles. The control inserts can, for example, be made of aluminum foil.

[0017] Preferably, the insulating body comprises a cured resin. For example, the high-voltage bushing can be impregnated with a curable resin during the manufacturing process, such as after the insulating layers have been wound. After the resin has cured, an improved insulating body can be obtained. The insulating body is in the form of a compact block, thus eliminating the need for a primary gas insulation layer.

[0018] The invention further relates to an electrical device with a fluid-tight housing and a high-voltage feedthrough, wherein a device connection part is provided for receiving and contacting the high-voltage feedthrough.

[0019] Such an electrical device is known from the previously mentioned DE 10 2007 022 641 A1.

[0020] The object of the invention is to propose such a device that can be put into operation as easily as possible.

[0021] The problem is solved by a corresponding electrical device according to claim 6. The high-voltage bushing comprises a mounting flange for attaching the high-voltage bushing to a wall, wherein the mounting flange comprises a retaining part and a moving part, wherein the moving part is rotatably mounted relative to the retaining part with respect to a longitudinal direction of the high-voltage bushing, wherein the moving part is a rotating ring arranged concentrically around the retaining part.

[0022] The advantages of the electrical device according to the invention arise in particular from the advantages of the high-voltage bushing according to the invention described above. The high-voltage bushing according to the invention can be used in conjunction with the electrical device according to the invention in all described variants, embodiments, and combinations of preferred features.

[0023] Preferably, the device connection part is attached to the housing by means of a mounting section, from which a hollow receiving section made of an electrically non-conductive insulating material extends into the housing, wherein a metallic contact part is arranged at a closed, tapered end region, extending through the insulating material of the receiving section or extending it towards the closed end region. According to this embodiment of the invention, each device connection part has an open end approximately at the level of a housing cover of the electrical device housing, which allows the insertion of the plug section of the high-voltage feedthrough.In the insertion direction, a receiving section extends from the mounting section of the device connector into the interior of the housing. This receiving section is made of an insulating material that provides the necessary insulation between the contact piece, which operates at a high-voltage potential, and the housing of the electrical device, such as a transformer, which is at earth potential. To ensure the necessary dielectric strength, the receiving section and the plug-in section are designed to be form-fittingly complementary. The weight of the high-voltage bushing presses the plug-in section firmly against the inner wall of the receiving section, thus preventing voltage spikes between the high-voltage bushing and the device connector.

[0024] Preferably, the contact part is connected to a winding, for example a winding of a transformer, via a power supply line extending within the housing, such as a winding connection line. By inserting the high-voltage bushing into the device connection part, the inner conductor of the high-voltage bushing is in contact with the contact part, so that the high-voltage terminal of the high-voltage bushing is connected to a winding of the electrical device via the winding connection line.

[0025] According to a further embodiment of the invention, the power supply cable is equipped with a current sensor, for example, a current transformer. Because the current sensor is located inside the housing, it no longer needs to be laboriously integrated into the wiring harness during on-site assembly of the electrical device. In other words, the electrical device according to the invention can be put into operation quickly on-site. In this embodiment, the time-consuming installation of the current sensor is avoided. Advantageously, mounting openings are provided in the housing to allow access to the current sensor(s) after draining the insulating fluid.

[0026] Furthermore, a method for manufacturing an electrical device with a fluid-tight housing and a device connection part for receiving and contacting a high-voltage feedthrough is provided.

[0027] The task is to propose a procedure that is as easy to implement as possible, even for devices designed for high voltage ranges above 500 kV.

[0028] The problem is solved in a method according to the invention by inserting a high-voltage bushing according to the invention into the device connection part, wherein the moving part of the mounting flange of the high-voltage bushing is rotated about the longitudinal axis of the high-voltage bushing to align mounting elements of the high-voltage bushing with mounting elements of the device connection part.

[0029] The advantages of the method arise in particular from the advantages of the high-voltage bushing and the electrical device according to the invention, as described above. In connection with the method according to the invention, the high-voltage bushing and the electrical device can, of course, be used in all embodiments and combinations of preferred features.

[0030] The invention is described below with reference to the invention described in the Figure 1 and 2 The described examples will be explained in more detail. Figure 1 shows an embodiment of a high-voltage feedthrough according to the invention in a schematic partial cross-sectional view; Figure 2 Figure 1 shows an embodiment of an electrical device according to the invention in a schematic partial cross-sectional view.

[0031] In Figure 1Figure 1 shows a partial section of a high-voltage bushing 1. The high-voltage bushing 1 has an inner conductor 2. The inner conductor 2 is enclosed by an insulating body 3, which electrically isolates the inner conductor 2 from its surroundings. The inner conductor 2 extends along a longitudinal axis 4 of the high-voltage bushing 1. The high-voltage bushing 1 also includes an outer housing 5 for mechanical protection. A potential tap 7 is inserted into a recess 6 in the housing 5. The potential tap 7 allows the voltage and / or current at the high-voltage bushing 1 to be monitored. The potential tap 7 is designed to be connected to a measuring device.

[0032] A mounting flange 8 is provided for attaching the high-voltage bushing to a wall 14. The mounting flange 8 extends axially from the inner conductor 2 to the outside, with the inner conductor 2 passing through the mounting flange 8. The mounting flange 8 includes a retaining element 9. The retaining element 9 comprises a first element 10, which has a first cut 11 and a recess 12 for receiving a seal 13. The seal 13 serves to seal an interface between the mounting flange 8 and the wall 14, which is located in Figure 1The first element 10 of the retaining part 9 is arranged in a ring shape around the inner conductor 2, as indicated by a dotted line. The retaining part 9 further comprises a second element 15, which has a second cutout 16. The first and second elements 10, 15 are firmly connected to each other by means of a screw connection 17. The retaining part 9 is also firmly connected to the outer housing 5, so that no relative movement of the housing 5 and the retaining part 9 is possible. The first and second cutouts 11 and 16, respectively, form a guide groove 18. The mounting flange 8 further comprises a moving part, which is designed as a rotating ring 19. The rotating ring 19 is arranged concentrically to the retaining part 9 and to the inner conductor 2 and is movable about the longitudinal axis 4. The rotating ring 19 comprises a plurality of openings 20, 21, which are designed to receive fastening elements.The high-voltage bushing 1 can be attached to the wall 14 using the fasteners inserted into the openings 20, 21. The swivel ring 19 has a projection 22 on its inner side. The projection 22 engages in the guide groove 18, so that the swivel ring 19 is guided in the guide groove 18 during its rotation.

[0033] In Figure 2 Figure 1 shows a partial section of an electrical device in the form of a transformer 25 with a pluggable high-voltage bushing 26 and a device connection part 27 for receiving and contacting the high-voltage bushing 26. The high-voltage bushing 26 is shown in the illustration of the Figure 2The device connection part 27 is inserted into the device connection part 27 of the transformer 25. The device connection part 27 is attached to a housing wall 28. The housing wall 28 encloses a transformer housing of the transformer 25, which is filled with an insulating material, for example, insulating oil. The attachment is designed to be leak-proof, so that the insulating material cannot escape from the housing. The device connection part 27 includes a conductive connection part 29 for establishing an electrical connection between the high-voltage bushing 26 and the power supply line 41 of a winding (not shown) of the transformer 25, which is located inside the housing filled with insulating oil. Identical and similar components are included in the Figure 1 and 2 with the same reference numerals.

[0034] The high-voltage bushing 26 includes an inner conductor 2,The inner conductor 2 is designed as a waveguide made of aluminum or copper in the illustrated example. The inner conductor 2 is concentrically surrounded by an insulating body 3. The insulating body 3 comprises conductive control inserts 30ac for capacitive field control, which are arranged concentrically around the inner conductor 2. The control inserts 30ac are separated from each other by insulating layers 31ab made of a PET nonwoven fabric, which have been impregnated with resin after being wound onto the inner conductor 2. The control inserts 30a-c are arranged at a radial distance A of 2 mm from each other.

[0035] The high-voltage bushing 26 further comprises a plug-in section 32 for inserting the high-voltage bushing 26 into the device connection part 27. The plug-in section 32 includes a conically tapered portion of the insulating body 3 and a connecting conductor section, which is welded to the inner conductor 2 in the form of a conductor stud 33. A pluggable contact system 34 is connected to the conductor stud 33, establishing the electrical connection between the high-voltage bushing 26 and the transformer 25.

[0036] A gap 35 between the plug section 32 of the high-voltage feedthrough 26 and the device connection part 27 is filled with a silicone material that dielectrically solidifies the gap 35.

[0037] The high-voltage bushing 26 further comprises a mounting flange 8 with a retaining element 9 and a movable element 19 in the form of a rotating ring. The retaining element 9 is fixed to the insulating body 2 of the high-voltage bushing 26. The movable element 19 is concentric and rotatable about a longitudinal axis 4 of the high-voltage bushing 26.

[0038] To manufacture the electrical device 25, the high-voltage bushing 26 is inserted into the device connection part 27 along the longitudinal axis 4 and in the direction that is Figure 2as indicated by arrow 36. After inserting the plug 32 into the device connection part 27, the high-voltage bushing 26 can no longer be readjusted with respect to its rotational position. To align the fastening elements 36a,b with respect to their intended position, the moving part 19 of the mounting flange 8 of the high-voltage bushing 26 is rotated about the longitudinal axis 4 of the high-voltage bushing 26 relative to the fastening elements 37a,b of the device connection part 27. The mounting flange 8 can then be mechanically connected to the device connection part 27.

[0039] It can be seen that the device connection part 27 has a mounting section 38 with which it is firmly mounted to the housing wall 28. Suitable screw connections are used for this purpose, for example. Sealing elements, not shown in the figures, are provided to fasten the device connection part 27 to the housing wall 28 in an insulating-tight manner.

[0040] The device connection part 27 further comprises a receiving section 39 made of an electrically non-conductive material. The receiving section 39 tapers towards a closed end. At this closed end, the wall of the receiving section 39 is penetrated by a bolt-shaped connection or contact part 29. The contact part 29 is connected to a power supply line 41 at the section of this contact part that projects into the interior 40 or oil chamber of the housing. The power supply line, which in the illustrated embodiment is a winding connection line 41, is also equipped with a current sensor in the form of a current transformer (not shown). The current transformer is thus permanently installed in the housing and serves to detect an electric current flowing to or from the respective winding via the winding connection line 41.

[0041] The plug-in section 32 of the high-voltage bushing 26 extends from the mounting flange 8 into the receiving section 39 of the device connection part 27. The outer wall of the silicone space 35, which is positively connected to the plug-in section 32, is shaped to be complementary to the receiving section 39, so that the two components fit together precisely and air or other inclusions are avoided.

Claims

1. A high-voltage feed-through (1) comprising an inner conductor (2) that extends in a longitudinal direction (4) between a high-voltage connection and a mating section (32) of the high-voltage feed-through (1); and an attachment flange (8) so as to attach the high-voltage feed-through (1) to a wall (14), wherein, the attachment flange (8) comprises a holding part (9) and a movable part (19), wherein the movable part (19) is mounted so as to be able to rotate relative to the holding part (9) with respect to a longitudinal direction (4) of the high-voltage feed-through (1), wherein the movable part (19) is a rotating ring which is arranged concentrically around the holding part (9), wherein the rotating ring (19) has a protrusion (22) on its inner face which engages in an outer guide groove (18) of the holding part (9), wherein the holding part (9) is designed at least in two pieces with a first and a second annular element (10, 15), wherein the first element (10) comprises a first outer indentation (11) and the second element (15) comprises a second outer indentation (16), wherein after the elements (10, 15) have been brought together the two indentations (11, 16) form the guide groove (18).

2. The high-voltage feed-through (1) as claimed in claim 1, wherein the holding part (9) is fixed with respect to an outer housing (5) of the high-voltage feed-through (1).

3. The high-voltage feed-through (1) as claimed in one of the preceding claims, wherein the mating section (32) is configured so as to plug the high-voltage feed-through (1) into a device connection part (27) of an electrical device (25), wherein the mating section (32) comprises an outer coating of a flexible insulating coating material.

4. The high-voltage feed-through (1) as claimed in one of the preceding claims, wherein an insulating body (3) comprises field-controlling control inserts (30a-c) that are separated from one another by insulating layers (31a,b), and wherein the control inserts (30a-c) are arranged in a concentric manner around the inner conductor (2).

5. The high-voltage feed-through (1) as claimed in one of the preceding claims, wherein the insulating body (3) comprises a hardened resin.

6. An electrical device (25) having a fluid-tight housing and a high-voltage feed-through (1) as claimed in one of claims 1 - 5, wherein a device connection part (27) is provided so as to receive and contact the high-voltage feed-through (1).

7. The electrical device (25) as claimed in claim 6, wherein the device connection part (27) is attached by means of an attachment section (38) to the housing from which a hollow receiving section (39) extends from an electrically nonconductive insulating material into the housing, wherein a metal contact part (29) is arranged on a closed tapering end region, said metal contact part extending through the insulating material of the receiving section (39) or increasing the length of said receiving section towards the closed end region.

8. The electrical device (25) as claimed in one of the preceding claims 6 or 7, wherein the contact part (29) is connected to a convertor winding via a current connection line (41) that extends within the housing.

9. The electrical device (25) as claimed in one of the preceding claims 6 to 8, wherein the current connection line (41) is equipped with a current sensor.