Method for producing a high-voltage insulator and high-voltage insulator

Abstract

Method for producing a high-voltage insulator (1) comprising the steps: - providing a substantially rotationally symmetrical insulating tube (2), - applying an insulating jacket (3) to the insulating tube (2), - fastening at least one flange (4) to at least one end of the insulating tube (2), - applying at least one insulating tape (5) circumferentially to the insulating tube (2), wherein - the insulating tube (2) is made of a first insulating material, - the insulating jacket (3) and the at least one insulating strip (5) are made of a second insulating material, - the at least one flange (4) is made of a third material, characterized in that - the first insulating material is made of glass fibre reinforced plastic, - the second insulating material is made of silicone.

Description

[0001] The invention relates to a method for producing a high-voltage insulator and a corresponding high-voltage insulator.

[0002] High-voltage insulators usually have an insulating tube made of glass-fiber reinforced plastic, a silicone shielding on top, and flanges connected to the insulating tube that serve as a fastening device.

[0003] High-voltage insulators for high-voltage equipment, such as transformers, are exposed to severe physical and chemical stresses throughout their service life. These stresses can be electrical or mechanical in nature and are influenced by local ambient and environmental conditions. Particularly near the flanges, in the so-called triple-point area where the insulating tube, silicone shielding, and flange meet, the high field strength prevailing in this area can lead to partial electrical discharges, which can damage the insulating material and shorten the service life of the high-voltage insulator.

[0004] DE 36 40 180 A1 discloses a high-voltage-resistant, vacuum-tight electrical feedthrough for cryogenic applications. The feedthrough comprises an insulating body manufactured by winding resin-impregnated glass fiber bundles onto a winding mandrel. First, a first, inner, tubular wound portion is applied to the winding mandrel, and then several conductor pieces are arranged on its outer surface. A further, central, tubular wound portion made of resin-impregnated glass fiber bundles is then created around this structure in a similar manner. This intermediate product is cured and post-processed before a flange made of metallic material is attached to the outer surface of the insulator body. The flange comprises an annular flange portion and two thin-walled base portions that project axially relative to the flange portion.After the flange is attached, the protruding foot sections are wrapped with resin-impregnated fiberglass strands, forming outer winding sections that tightly enclose the foot sections. The inner winding section, the middle winding section, and the outer winding sections are all made of the same material: resin-impregnated fiberglass bundles.

[0005] It is therefore an object of the present invention to provide an improved concept for a high-voltage insulator which has a long service life and can be manufactured with little effort.

[0006] This object is achieved by the respective subject matter of the independent claims. Further embodiments are the subject matter of the dependent claims.

[0007] According to a first aspect of the improved concept, a method for producing a high-voltage insulator having the features of claim 1 is provided. A substantially rotationally symmetrical insulating tube is provided, an insulating jacket is applied to the insulating tube, at least one flange is attached to at least one end of the insulating tube, and then at least one insulating tape is applied circumferentially to the insulating tube.

[0008] According to one embodiment of the method, the next step involves vulcanizing the high-voltage insulator, preferably in an oven designed for this purpose.

[0009] The insulating sheath has several shielding rings extending radially outwards, which serve to extend the creepage path.

[0010] The flange is attached using an adhesive, for example.

[0011] According to the invention, the insulating tube is formed from a first insulating material, the insulating jacket and the at least one insulating strip are formed from a second insulating material and the at least one flange is formed from a third material.

[0012] According to the invention, the first insulating material is formed as a glass-fiber-reinforced plastic. The insulating tube is preferably made of glass-fiber-reinforced plastic using known winding methods, wherein resin-impregnated fiber elements are wound in multiple layers onto a rotating winding core.

[0013] According to the invention, the second insulating material is formed from silicone, preferably from heat-curing (HTV) silicone rubber. Constructing the insulating jacket and the insulating tape from the same material, namely HTV silicone, offers the advantage of higher tracking resistance and, consequently, higher flame resistance of the high-voltage insulator.

[0014] According to a further embodiment, the third material from which the flange is formed is formed as metal, preferably as aluminum.

[0015] According to a further embodiment, the insulating jacket is made of liquid silicone and the at least one insulating tape is made of silicone rubber.

[0016] According to a further embodiment, the insulating jacket is applied in a first region of the insulating tube, the at least one flange is fastened in a second region of the insulating tube, and the at least one insulating tape is applied in a third region of the insulating tube. The third region extends at least partially over the first region and / or the second region relative to a longitudinal axis L of the insulating tube, and the first region and the second region are spaced apart from one another relative to the longitudinal axis L of the insulating tube.

[0017] The insulating tape is therefore arranged in the area between the insulating jacket and the flange on the insulating tube, where, due to the geometry of the high-voltage insulator and the different materials, a strong electric field typically exists, which poses an increased risk of partial discharges. The insulating tape reduces the electric field strength in the triple-point area. This, especially after the insulating jacket and insulating tape have been vulcanized together, increases the tightness of the high-voltage insulator and thus provides the best possible shielding against environmental influences and surges.

[0018] According to a further embodiment, the insulating jacket is applied using an injection molding process. Specifically, this means that the insulating jacket, including the shielding rings, is preferably produced by casting the second insulating material around the insulating tube. In addition to the casting process, however, any other suitable and well-known methods for producing the insulating jacket are also possible.

[0019] According to another embodiment, the insulating tape is applied using an extrusion process. For example, the insulating tape is sprayed circumferentially onto the insulating tube rotating around its rotational axis R using an extruder. Applying the insulating tape by extrusion has the advantage, from a manufacturing perspective, over other manufacturing techniques, such as injection molding, that the insulating tube is subjected to lower compressive forces during application of the insulating tape.

[0020] According to a second aspect of the improved concept, a high-voltage insulator having the features of claim 4 is also provided.

[0021] The features of the high-voltage insulator correspond to the steps of the method according to the first aspect of the improved concept. For the high-voltage insulator according to the second aspect of the improved concept, reference is therefore made to the advantageous explanations, preferred features, technical effects, and / or advantages in an analogous manner to those already explained for the method according to the first aspect and the corresponding embodiments of the method. Repetition is omitted.

[0022] The high-voltage insulator comprises a substantially rotationally symmetrical insulating tube, an insulating jacket arranged circumferentially on the insulating tube, at least one flange arranged at at least one end of the insulating tube, and at least one insulating tape arranged circumferentially on the insulating tube.

[0023] According to the invention, the insulating tube is formed from a first insulating material, the insulating jacket and the insulating tape are formed from a second insulating material and the flange is formed from a third material.

[0024] According to a further embodiment, the insulating jacket is arranged in a first region of the insulating tube, the at least one flange is arranged in a second region of the insulating tube, and the at least one insulating strip is arranged in a third region of the insulating tube. The third region extends at least partially over the first region and / or the second region relative to a longitudinal axis L of the insulating tube, and the first region and the second region are spaced apart from one another relative to the longitudinal axis L of the insulating tube.

[0025] According to a further embodiment, the at least one flange and the insulating jacket together with the insulating tube form a circumferential groove in which the at least one insulating tape is arranged.

[0026] The invention will now be explained in detail using exemplary embodiments with reference to 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 functions may only be explained with reference to the figure in which they first appear. The explanation is not necessarily repeated in subsequent figures.

[0027] It shows Fig. 1 shows an exemplary embodiment of a high-voltage insulator according to the improved concept; Fig. 2 a sectional view of the high-voltage insulator from Fig. 1; Fig. 3 a detailed view of the high-voltage insulator from Fig. 1 and Fig. 2; Fig. 4 a schematic representation of a method step of an advantageous embodiment of a method according to the improved concept; Fig. 5 an advantageous embodiment of the method according to the improved concept.

[0028] Fig. 1 and Fig. 2 show an exemplary embodiment of a high-voltage insulator 1 according to the improved concept, wherein Fig. 1 the high-voltage insulator in a perspective view and Fig. 2 shows the high-voltage insulator in a sectional view.

[0029] The high-voltage insulator 1 comprises a substantially rotationally symmetrical insulating tube 2 made of glass-fiber-reinforced plastic. An insulating jacket 3 with radially extending shielding rings 10 made of HTV silicone is arranged circumferentially on the insulating tube 2 in a first region 6 relative to the longitudinal axis L of the insulating tube 2. An aluminum flange 4 is attached to each of the two ends of the insulating tube 2. Likewise, an insulating tape 5 is arranged circumferentially on the insulating tube 2 between the respective flange 4 and the insulating jacket 3 at each of the two ends of the insulating tube 2. The two insulating tapes 5, like the insulating jacket 3, are made of HTV silicone.

[0030] In Fig. 3 shows a detailed view of the high-voltage insulator 1 in section along the longitudinal axis L of the insulating tube 2. In a second region 7 relative to the longitudinal axis L, the flange 4 is arranged, and in a third region 8 relative to the longitudinal axis L, the insulating tape 5 is arranged. In the first region 6 relative to the longitudinal axis L of the insulating tube 2, the insulating tube 2 is covered with the insulating jacket 3, wherein in this detailed view, only a section of the region 6 is shown, which borders on the other regions 7 and 8. The first region 6 and the second region 7 are spaced apart from one another relative to the longitudinal axis L, i.e., the insulating jacket 3 and the flange 4 do not touch one another. The insulating tube 2, the insulating jacket 3, and the flange 4 form a circumferential groove 9 in which the insulating tape 5 is arranged. The third region 8 extends relative to the longitudinal axis L partly over the first and second regions 6 and 7, i.e.,the insulating tape 5 partially covers the insulating jacket 3 and the flange 4 to ensure complete sealing of the triple point area.

[0031] In Fig. 4 shows the application of the insulating tape 5 according to an advantageous embodiment of a method according to the improved concept. By means of an extruder 11, the insulating tape 5 is extruded into the groove 9 of the insulating tube 2 rotating about a rotation axis R. The amount of HTV silicone applied is such that the insulating tape 5 extends, relative to the longitudinal axis L of the insulating tube 2, over at least part of the region 6 in which the insulating jacket 3 is arranged and at least part of the region 7 in which the flange 4 is arranged. In concrete terms, this means that the insulating tape 5 is extruded over part of the surface of the flange 4 and the insulating jacket 3.

[0032] Fig.5 shows a flow diagram of an advantageous embodiment of a method according to the improved concept. In a step a, a substantially rotationally symmetrical insulating tube 2 is provided. In a step b, an insulating jacket 3 is applied to the insulating tube 2. In a step c, at least one flange 4 is attached to at least one end of the insulating tube 2. In a step d, at least one insulating tape 5 is applied circumferentially to the insulating tube 2, preferably by means of an extruder 11. In a step e, the high-voltage insulator 1 is vulcanized. In a step f, the high-voltage insulator 1 is cured. REFERENCE SYMBOL 1 high-voltage insulator 2 insulating pipes 3 Insulating jacket 4 Flange 5 insulating tape 6 first area of ​​2 7 second area of ​​2 8 third area of ​​2 9 grooves 10 umbrella rings of 3 11 extruders L Longitudinal axis of 2 R rotation axis of 2

Claims

[1] Method for producing a high-voltage insulator (1) comprising the steps: - providing a substantially rotationally symmetrical insulating tube (2), - applying an insulating jacket (3) to the insulating tube (2), - fastening at least one flange (4) to at least one end of the insulating tube (2), - applying at least one insulating tape (5) circumferentially to the insulating tube (2), wherein - the insulating tube (2) is made of a first insulating material, - the insulating jacket (3) and the at least one insulating strip (5) are made of a second insulating material, - the at least one flange (4) is made of a third material, characterized by , that - the first insulating material is made of glass fibre reinforced plastic, - the second insulating material is made of silicone. [2] The method according to claim 1, wherein - the insulating jacket (3) is applied in a first region (6) of the insulating tube (2), - the at least one flange (4) is fixed in a second region (7) of the insulating tube (2), - the at least one insulating tape (5) is applied in a third region (8) of the insulating tube (2), wherein - the third region (8) extends at least partially over the first region (6) and / or the second region (7) with respect to a longitudinal axis L of the insulating tube (2), - the first region (6) and the second region (7) are spaced apart from one another with respect to the longitudinal axis L of the insulating tube (2). [3] Method according to one of the preceding claims, wherein - the insulating jacket (3) is applied by means of an injection molding process, and / or - the at least one insulating tape (5) is applied by means of an extrusion process. [4] High-voltage insulator (1) comprising - a substantially rotationally symmetrical insulating tube (2), - an insulating jacket (3) arranged circumferentially on the insulating tube (2), - at least one flange (4) arranged at at least one end of the insulating tube (2), - at least one insulating tape (5) arranged circumferentially on the insulating tube (2), wherein - the insulating tube (2) is made of a first insulating material, - the insulating jacket (3) and the at least one insulating strip (5) are made of a second insulating material, - the at least one flange (4) is made of a third material, characterized by , that - the first insulating material is made of glass fibre reinforced plastic, - the second insulating material is made of silicone. [5] High-voltage insulator (1) according to claim 4, wherein - the insulating jacket (3) is arranged in a first region (6) of the insulating tube (2), - the at least one flange (4) is arranged in a second region (7) of the insulating tube (2), - the at least one insulating tape (5) is arranged in a third region (8) of the insulating tube (2), wherein - the third region (8) extends at least partially over the first region (6) and / or the second region (7) with respect to a longitudinal axis L of the insulating tube (2), - the first region (6) and the second region (7) are spaced apart from each other with respect to the longitudinal axis L of the insulating tube. [6] High-voltage insulator (1) according to claim 5, wherein - the at least one flange (4) and the insulating jacket (3) together with the insulating tube (2) form a circumferential groove (9) in which the at least one insulating strip (5) is arranged.

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