INSULATOR FOR HIGH-VOLTAGE APPLICATIONS

Description

[0001] The invention relates to an insulator for high-voltage applications, in particular a support insulator, such as those used for supporting busbars, conductor cables, chokes, or other equipment in high-voltage technology. This equipment operates at a specific potential and therefore must be insulated from earth and / or other potentials at a certain distance.

[0002] For many decades, single-piece or multi-piece support insulators, i.e., consisting of several individual insulators and composite components, have been used to support and insulate busbars, conductor cables or choke coils from earth.

[0003] Documents DE102010015729A1, US2021 / 027920A1 and CN110534267A contain examples of high-voltage insulators.

[0004] From WO 2018 / 191159 A1, an air-core choke for use in an electrical power transmission and distribution network is known, which is mounted on an electrically insulated support structure and insulated from earth. The support structure comprises several support insulators, each of which has a mounting bracket at its upper end that is directly connected to the coil. For attaching the mounting bracket to the support insulator, the support insulator has a mounting flange that is screwed and bonded to a flange of the support insulator.

[0005] The entire system is subjected to high forces, particularly bending, torsional, tensile, and compressive forces, due to the high currents and voltages and the resulting magnetic fields, as well as environmental influences such as local weather conditions. The flange connection between the coil and its mounting devices and the support insulators represents a weak point and thus a potential source of failure.

[0006] Furthermore, the on-site installation of the mounting brackets onto the flanges of the support insulators is complex, as each mounting bracket must be correctly positioned and then securely fastened with several screws. Any angular misalignments that may occur must also be corrected during this process.

[0007] It is an object of the present invention to provide an improved concept for connecting a support insulator with a bracket for high-voltage equipment, which, in addition to high strength, also enables easy on-site assembly of the device.

[0008] This problem is solved by the subject matter of the independent claim. Further embodiments are the subject matter of the dependent claims.

[0009] The design envisages an insulator for high-voltage applications, specifically a support insulator, comprising a substantially rotationally symmetrical hollow tube made of glass fiber reinforced epoxy resin, a silicone shield attached circumferentially to the hollow tube, and a base flange located at a lower end relative to a longitudinal axis A of the hollow tube. At an upper end relative to the longitudinal axis A of the hollow tube, the insulator has a mounting for a device for high-voltage applications. Such devices could, for example, be a choke coil supported on several insulators by means of a toothed ring, or a busbar held at a distance from ground by the insulator.

[0010] Furthermore, the insulator has a sealing element located inside the hollow tube, which closes the end face of the upper end with respect to the longitudinal axis A of the hollow tube and seals it to the outside. The sealing element is preferably designed as a circular plug, the diameter of which interacts with the inner diameter of the hollow tube in such a way that the hollow tube is sealed airtight.

[0011] The bracket has a rotationally symmetrical connection area. This connection area is located at one end of the bracket, facing the hollow tube. The insulator has a radially circumferential joining area at its upper end, relative to the longitudinal axis A of the hollow tube, which is free of silicone shielding. The bracket can be connected to the insulator in such a way that the connection area of ​​the bracket fits snugly around the joining area of ​​the insulator.

[0012] The improved design thus offers a connection technology between the support insulator and a device for high-voltage applications that is detachable yet stable and easy to install. The bracket can be attached to the support insulators on-site, with or without the device for which it is intended. Bonding the bracket to the hollow tube is not required.

[0013] According to the invention, the locking element, the hollow tube, and the bracket each have at least one transverse bore that are aligned coaxially with each other. A locking bolt can be inserted into each of the at least one transverse bore and secured therein, for example, with one or more nuts. Preferably, two locking bolts are used, arranged perpendicular to each other and one above the other.

[0014] The locking bolt allows the connection to remain detachable. At the same time, the bracket is fixed in place depending on the locking element and the hollow tube, thereby further reinforcing the connection with regard to positive locking.

[0015] The locking bolt is preferably made of steel, plastic, in particular glass fiber reinforced plastic, or ceramic material.

[0016] According to a further embodiment of the improved concept, the positive-locking connection between the holder and the insulator, in particular the joining area of ​​the insulator, is designed as a conical connection.

[0017] Preferably, the conical connection is designed such that the outer diameter of the insulator's hollow tube decreases towards the upper end with respect to the longitudinal axis A. Accordingly, the inner diameter of the mounting bracket's connection area increases towards the end of the bracket facing the hollow tube.

[0018] The conical design of the connection allows the bracket to self-center on the insulator, thus simplifying the installation of the equipment on the support insulators. Furthermore, the conical connection offers greater strength compared to a conventional flange connection, particularly under shear forces, due to the improved positive locking.

[0019] According to another embodiment of the improved concept, the locking element and the holder are made of a non-metallic material.

[0020] Preferably, the non-metallic material of the holder is made of fiber-reinforced plastic, particularly preferably of glass fiber-reinforced epoxy resin. The holder can be manufactured, for example, by injection molding, vacuum infusion, and / or winding processes.

[0021] Preferably, the non-metallic material of the closure element is made of fiber-reinforced plastic, particularly preferably of glass fiber-reinforced epoxy resin. The closure element can be manufactured, for example, by injection molding, vacuum infusion, and / or winding processes.

[0022] Preferably, the non-metallic material of the closure element can also be made of a ceramic material.

[0023] The use of non-metallic material for the components prevents them from being heated by the surrounding magnetic fields.

[0024] According to a further embodiment of the improved concept, the bracket has means for fastening at least one busbar. Preferably, the bracket has a first U-shaped recess and a second U-shaped recess opposite the first, which are located outside the connection area and are suitable for receiving a busbar.

[0025] Preferably, the holder for fastening the at least one busbar further comprises a spring element that fixes the at least one busbar in the U-shaped recesses depending on the holder.

[0026] According to a further embodiment of the improved concept, the bracket has means for attaching at least one choke coil. Preferably, the bracket has a first and a second groove located outside the connection area and suitable for receiving a toothed ring.

[0027] According to a further embodiment of the improved concept, the support forms the lower end, relative to a longitudinal axis, of a hollow tube of another insulator, or a part of the lower end of the hollow tube of another insulator. Preferably, the insulators are identical to each other. In particular, the insulators together form a multi-part support insulator.

[0028] Further embodiments and implementations of the insulator result directly from the various embodiments.

[0029] The invention is explained in detail below with reference to exemplary embodiments and the drawings. Components that are identical, functionally identical, or have an identical effect may be provided with identical reference numerals. Identical components or components with identical function may be explained only with respect to the figure in which they first appear. The explanation is not necessarily repeated in the subsequent figures.

[0030] They show Figure 1 shows an advantageous embodiment of the insulator according to the improved concept in a side view; Figure 2 shows a detailed view of the insulator. Figure 1 in a perspective view; Figure 3, another detailed view of the insulator from Figure 1 in an exploded view and sectional view; Figure 4 shows a further detailed view of the insulator. Figure 1Figure 5 shows a side view and sectional view; Figure 5 shows a detailed view of a further advantageous embodiment of the insulator according to the improved concept in a perspective view; Figure 6 shows a further detailed view of the insulator made of Figure 4 in a side view and sectional view.

[0031] Figure 1Figure 1 shows an advantageous embodiment of the insulator according to the improved concept in a side view. The insulator 1 has a substantially rotationally symmetrical hollow tube 2 made of glass fiber reinforced epoxy resin with a silicone shield 3 attached circumferentially to the hollow tube 2. A foot flange 4 is arranged at a lower end 5 with respect to a longitudinal axis A of the hollow tube 2, on which the insulator 1 is supported in a vertical position. A bracket 6 for a device for high-voltage applications is attached to an upper end 7 of the hollow tube 2 opposite the lower end 5. Such devices can be, for example, a choke coil supported on one or more insulators by means of a toothed ring, or a busbar held at a distance from ground by the insulator. In the case of the Figure 1The bracket 6 is designed for a choke coil. A bracket for a busbar will be discussed in more detail in the explanation of another embodiment variant. Another possible component is an additional insulator. In this case, the insulator is composed of several separate insulators that can be connected to each other via the bracket 6. The additional insulator then no longer has a base flange; instead, the bracket 6 is formed as part of the hollow tube 2 at its lower end 5.

[0032] Figure 2 shows a detailed view of the insulator. Figure 1in a perspective view. More precisely, the upper end 7 of the insulator 1 with the mounted bracket 6 is shown in detail. The silicone shielding 3, which has been applied to the hollow tube 2, and the rotationally symmetrical bracket 6 are visible. In this embodiment, the bracket 6 serves to support a choke coil. For this purpose, the bracket 6 has two opposing grooves 14 for receiving a toothed ring and several teardrop-shaped recesses 13 for fixing the toothed ring and the coil by means of resin-impregnated fiber bundles, which are threaded through the recesses 13.

[0033] Another detailed view of the insulator from Figure 1 is shown in an exploded view and section view in Figure 3 shown. Here, the bracket 6 is shown separately from the hollow tube 2 in order to clearly illustrate the closure of the hollow tube 2 and the connection between the bracket 6 and the hollow tube 2.

[0034] The insulator 1 or the hollow tube 2 has a sealing element 8, which is arranged at the upper end 7 of the hollow tube 2 in its inner cavity and is designed as a circular plug, and whose diameter DV is dimensioned such that the plug 8 seals the end face of the hollow tube 2 airtight and provides a seal to the external environment. The diameter DV is, for example, in a range between 150 mm and 600 mm, preferably between 200 mm and 580 mm.

[0035] The bracket 6 includes a connection area 9 at its end facing the hollow tube 2. This connection area 9 interacts with a radially circumferential joining area 10 located at the upper end 7 of the hollow tube 2. The joining area 10 is free of silicone shielding 3 and has an outer diameter DA that decreases along the longitudinal axis A from a maximum diameter DAmax towards the upper end 7 of the hollow tube 2 to a minimum diameter DAmin. Accordingly, the inner diameter DI of the connection area 9 of the bracket 6 increases from a minimum diameter DImin towards the end facing the hollow tube 2 to a maximum diameter DImax. The difference between the respective maximum outer and inner diameters DAmax and DImax and the respective minimum outer and inner diameters is theThe inner diameter DA min, DI min, which is ultimately the width of the cone, lies in a range between 10 mm and 50 mm, preferably with a difference of 20 mm. The minimum outer and inner diameters DA min and DI min can be, for example, 200 mm, 350 mm, or 580 mm, and the maximum outer and inner diameters DA max and DI max can be, accordingly, 220 mm, 370 mm, or 600 mm.

[0036] During assembly, the bracket 6 is placed onto the joining area 10 of the hollow tube 2, so that its connection area 9 positively surrounds the joining area 10, i.e., completely surrounds it. This is in Figure 4 in a further detailed view of the insulator Figure 1The diagram shows a side view and a sectional view. The conical shape of the joining area 10 and the connection area 9 relative to each other ensures that the holder 6 positively surrounds the hollow tube 2 in its joining area 10, i.e., completely, and can be positioned on the hollow tube 2 in a self-centering manner during assembly.

[0037] The holder 6, the hollow tube 2, and the closure element 8 or plug each have two transverse bores 11. The transverse bores 11 are each coaxially aligned with each other. A locking bolt 12 is inserted through each of these bores and secured in them by means of two nuts. The locking bolts 12 are preferably made of steel, plastic, in particular glass fiber reinforced plastic, or ceramic.

[0038] In the Figures 5 and 6Each is a detailed view of a further advantageous embodiment of the insulator according to the improved concept, once from a perspective view ( Fig. 5 ) and once in a side view and section view ( Fig. 6 ) shown. Insulator 1 essentially corresponds to the previously explained insulator 1. Therefore, reference is made to the corresponding explanations in an analogous manner. The one in the Figures 4 and 5The insulator 1 shown differs, however, in that the bracket 6 is designed for mounting a busbar 15. This concept is used, for example, in substations for fixing busbars, where a certain distance from the ground must be maintained. Preferably, the bracket 6 has a first U-shaped recess 16 and a second U-shaped recess 16 arranged opposite the first, which are located outside the connection area 9 and are dimensioned to accommodate a busbar 15. A spring element 17, preferably a leaf spring, is provided to fix the busbar 15 in the U-shaped recess 16, which fixes the busbar 15 relative to the bracket 6 by pressing the busbar 15 into the U-shaped recess 16 with its spring force.

[0039] The improved concept presents a connection technology for the head fittings of support insulators in high-voltage applications. This technology is suitable for connecting a support insulator to a downstream pipe geometry, where the pipe geometry serves as a support for high-voltage equipment. Compared to a conventional flange connection, the improved connection technology offers the advantage of being detachable while still being able to withstand higher forces. The conical connection enables force transmission through friction and positive locking, as well as self-centering during assembly. The locking bolt allows the connection to be detachable, while simultaneously fixing the support in place depending on the locking element and the hollow pipe, thereby further reinforcing the connection with regard to positive locking. REFERENCE MARK

[0040] 1 Insulator 2 Hollow tube 3 Shielding 4 Foot flange 5 Lower end of 2 6 Bracket 7 Upper end of 2 8 Locking element 9 Connection area of ​​6 10 Joining area of ​​1 11 Transverse bore 12 Locking bolt 13 Recess 14 Groove 15 Busbar 16 U-shaped recess 17 Spring element A Longitudinal axis of 2 DA Outer diameter of 10 DA max Maximum outer diameter of 10 DI Inner diameter of 9 DI max Maximum inner diameter of 9 DV Diameter of 8

Claims

1. Insulator (1) for high-voltage applications comprising - a substantially rotationally symmetrical hollow tube (2) made of glass fiber reinforced epoxy resin, - a silicone shield (3) attached to the circumference of the hollow tube (2), - a base flange (4) at a lower end (5) of the hollow tube (2); characterized in that the insulator (1) comprises: - a bracket (6) for equipment for high-voltage applications at an upper end (7) of the hollow tube (2), wherein - the insulator (1) has a closure element (8), in particular a plug, which is arranged inside the hollow tube (2) and closes the end face of the upper end (7) of the hollow tube (2) and seals it to the outside, wherein - the holder (6) has a rotationally symmetrical connection area (9), - the insulator (1) has a radially circumferential joining area (10) at the upper end (7) of the hollow tube (2), which is free of silicone shielding (3), - wherein the holder (6) can be connected to the insulator (1) in such a way that the connection area (9) of the holder (6) surrounds the joint area (10) of the insulator (1) in a form-fitting manner, wherein - the closure element (8), the hollow tube (2), and the bracket (6) each have at least one transverse bore (11) that are aligned coaxially with each other, - a locking bolt (12) can be inserted into each of the at least one transverse bore (11) and fixed therein.

2. Insulator (1) according to claim 1, wherein - the positive connection between the bracket (6) and the insulator (1) is designed as a conical connection.

3. Insulator (1) according to one of the preceding claims, wherein - the locking element (8) and the holder (6) are made of a non-metallic material.

4. Insulator (1) according to one of the preceding claims, wherein - the holder (6) has means for fastening at least one busbar.

5. Insulator (1) according to one of the preceding claims, wherein - the bracket (6) has means for fastening at least one choke coil.

6. Insulator (1) according to one of the preceding claims, wherein - the bracket (6) forms the lower end of a hollow tube of a further insulator.