EP2283493B1 - Duct with a base active piece and an insulation device - Google Patents

Description

The invention relates to a bushing and an insulation device according to the preamble of the independent device claim and a method for producing a bushing according to the preamble of the independent method claim. The insulation device is used in high voltage engineering as a base element for the construction of bushings in the voltage range of 6 kV to 800 kV AC and DC voltage, but can also be used for measuring transformers, capacitors and supporters.

1. 1. Durchführung, bestehend aus kalandriertem Elektro-Isolierpapier oder Krepp-Isolierpapier, aufgewickelt auf ein Metallrohr oder einem Rohr aus Isoliermaterial oder einem Isolierstab mit eingelegten oder aufgedruckten/aufgedampften oder gespritzten Steuerelektroden aus Metall oder einer leitenden Materialschicht, imprägniert unter Vakuum mit Epoxydharz oder Polyurethan-Harz oder Isolierflüssigkeit, wie z. B. Mineralöl.
2. 2. Durchführung, bestehend aus kalandriertem Elektro-Isolierpapier oder Krepp-Isolierpapier, beschichtet mit einer Harzschicht im nicht polymerisierten Zustand, aufgewickelt unter Wärme und Druck auf einem Metallrohr oder einem Rohr aus Isoliermaterial, oder Zylinder oder Isolierstab mit eingelegten Steuer-Elektroden aus Metall oder leitender Materialschicht.
3. 3. Durchführung, bestehend aus Elektro-Kunststofffolien, wie z.B. Polypropylen- oder Polyester-Folien, aufgewickelt auf ein Metallrohr, Rohr aus Isoliermaterial oder Isolierstab mit integrierten Steuerfolien, bestehend aus eingelegten Al-Folien oder aufgedrucktem oder gespritztem Metall, vorzugsweise Aluminium oder einem leitenden Material und imprägniert unter Vakuum mit SF₆-Gas oder einer Isolierflüssigkeit.
4. 4. Durchführung, bestehend aus einer zylindrischen Erdelektrode und einem zylindrischen Stromleiter auf HS-Potential und einer Isolierstrecke zwischen Leiter und Erdelektrode aus SF₆-Gas mit einem Druck zwischen 1 bar und 10 bar.

The state of the art is the following bushings with integrated controls for high voltage arrangements between two potentials or between high voltage potential and ground potential.

1. 1. Carrying out, consisting of calendered electrical insulating paper or crepe insulating paper, wound on a metal tube or a tube of insulating material or an insulating rod with inserted or printed / vapor-deposited or sprayed metal control electrodes or a conductive material layer, impregnated under vacuum with epoxy resin or polyurethane Resin or insulating liquid, such as B. mineral oil.
2. 2. Procedure consisting of calendered electrical insulation paper or crepe insulation paper coated with a resin layer in the unpolymerized state, wound up under heat and pressure on a metal pipe or a tube of insulating material, or cylinder or insulating rod with inserted control electrodes of metal or conductive material layer.
3. 3. implementation, consisting of electro-plastic films, such as polypropylene or polyester films, wound on a metal tube, pipe made of insulating material or insulating rod with integrated control films, consisting of inserted aluminum foils or printed or sprayed metal, preferably aluminum or a conductive Material and impregnated under vacuum with SF ₆ gas or an insulating liquid.
4. 4. implementation, consisting of a cylindrical earth electrode and a cylindrical conductor on HS potential and an insulating gap between the conductor and ground electrode of SF ₆ gas at a pressure between 1 bar and 10 bar.

According to IEC standard 60137 for feedthroughs, the following insulated feedthroughs with integrated controls for high voltage arrangements can be distinguished between two potentials or between high voltage potential and ground potential: oil impregnated paper (OIP), resin impregnated paper (RIP), resin coated paper (RBP) and gas insulated insulators. Applications are as follows: Feedthroughs for transformers, feedthroughs for GIS systems, where GIS stands for "gas insulated switchgear", connections of GIS systems with transformers, wall feedthroughs or generator feedthroughs. The same isolation devices are also used for high-voltage transducers.

The following controls can be distinguished: a continuous control with variable electrode width, a double control with a constant width, a simple control with a constant width, a coarse control with ring electrode at the edge of the layer or a coarse control with earth electrode.

The different technologies have different advantages and disadvantages. For oil-impregnated paper (OIP) there is a high permissible operating field strength, an organic dielectric, cost-effective production, high reliability, long life, flexible dielectric, very good heat transfer (conductor-insulator surface) and TE use values of 2 pC up to 5 pC, which are easily accessible. A disadvantage is the presence of degradable mineral oil or vegetable oil between the active part and the insulator wall, which can flow out if damaged. Another disadvantage is a limitation of the permissible field strength by the strength of the impregnated insulating paper, a horizontal mounting position is possible only with built-in compensator and a need for porcelain or composite insulator for operation.

For resin impregnated paper (RIP), allowable field strength, similar to that of OIP, is a dry dielectric, a mounting orientation independent, and silicone screens that can be applied directly to the active part. The disadvantage is a complex and material-intensive production process (more expensive than OIP), TE values must be <2 pC for life expectancy, inelastic active part can cause internal stresses, poor thermal conductivity of the dielectric compared to OIP, no organic Dielectric and an epoxy resin outer surface of the active part, which must be over-turned.

Resin-coated paper (RBP) is characterized by a dry dielectric and a mounting orientation. A disadvantage is a low TE input voltage, high permissible TE values during operation, which are not tolerated by a transformer builder and an active part outer surface, which must be over-turned.

For gas-insulated devices that z. B. use SF ₆ as a gas, a dry dielectric, a mounting position independence, a simple manufacturing process and a TE value <2 pC. The disadvantage is a limitation of the permissible field strength at the ply edges by the SF ₆ gas and its gas pressure, thereby no high utilization of the dielectric is possible. Another disadvantage is an undesirable affiliation of the SF ₆ gas to the greenhouse gases, a negative pressure of the insulator, which usually requires the use of composite insulators for safety reasons, as well as a limitation of the minus temperature range down by the gas pressure.

As an example of an insulating device for a bushing according to the prior art is in Fig. 1 a standard solution of the technologies described above under the points 1 and 4 for the controlled solution implementation. Line 501 is a potential line determined by control pads 502. An insulation 503 of oil paper or gas-impregnated film is between a conductor 504 at high voltage potential and an electrode 505. A base active part 506 is hermetically sealed from the environment by a porcelain insulator or composite insulator 507 completed. A gap or gap 508 between the active part and the insulator is filled with an insulating liquid or insulating gas, such as air, SF ₆ , N ₂ , etc. under pressure of 1 bar to 6 bar. A high voltage is applied to a terminal 509. A high voltage electrode 510 has the same potential as the terminal 509. A terminal 511 to the transformer or the gas insulated switchgear (GIS) is connected to the terminal 509 through the conductor 504. The control electrode 505 is connected to a flange 512 and connected to ground potential 513. The document US 4,362,897 A discloses a bushing according to the preamble of claim 1. The present invention has for its object to provide a bushing and an insulating device, which do not have the disadvantages associated with a conventional implementation or isolation device described above, regardless of the mounting position, no porcelain or composite insulators and can be easily manufactured.

This object is achieved by the inventive implementation, as defined in independent claim 1. The independent claim 8 relates to a method for producing a novel implementation with a base-active part and an insulating device. Advantageous embodiments will become apparent from the dependent claims.

In particular, in the implementation according to the invention with a base active part and an insulating device, the base active part comprises a conductor, plastic-electro-foils, control electrodes and an earth electrode. The insulation device has a shrink tube made of an electrically insulating material.

The basic active part together with the shrink tube allows a hermetically sealed base-active part without insulator which is synonymous with a dry active part. Also, any mounting position is possible in the inventive implementation, there are no porcelain or composite insulators needed and the inventive implementation can be made low.

1. a) $${\left|\overrightarrow{E}\right|}_{U=U_P}\le {\left|\overrightarrow{E}\right|}_{\mathit{TE}-\mathit{Einsatzspannung}}$$
   
2. b) $${\left|\overrightarrow{E}\right|}_{U=U_P}\le \frac{U_d}{d_F}=\frac{\mathit{Durchschlagspannung}}{\mathit{Dielektrikumsdicke}}$$
   

In particular, in the inventive implementation, the plastic-electro-foils, the control electrodes and their edges are provided with a low-viscosity insulating under vacuum, the insulating liquid has a viscosity between 8 mm ² / s and 20 mm ² / s at 40 ° C, or with an alternative low-viscosity insulating liquid which cross-links at a crosslinking temperature of at least 50 ° C, the alternative insulating liquid having a viscosity between 20 mm ² / s and 100 mm ² / s at 40 ° C. Impregnation with a flexible silicone gel or insulating liquid of high dielectric strength (high TE field strength) results in an elastic dielectric and allows the use of an inventive insulating device for implementation in the following temperature ranges, which are typically required for such insulation: Outside temperature of -50 ° C to + 60 ° C resp. Operating temperature due to self-heating of the insulation device from -50 ° C to + 120 ° C. There is thus no impregnation with an epoxy or polyurethane resin system instead. The insulating device has a good thermal conductivity and achieves a high utilization of the dielectric, wherein the Field strengths in the AC test can be determined by the following two criteria:

1. a) $${\left|\overrightarrow{e}\right|}_{U=U_P}\le {\left|\overrightarrow{e}\right|}_{\mathit{TE}-\mathit{threshold\; voltage}}$$
   
2. b) $${\left|\overrightarrow{e}\right|}_{U=U_P}\le \frac{U_d}{d_F}=\frac{\mathit{Breakdown\; voltage}}{\mathit{dielectric\; thickness}}$$
   

In particular, in the inventive implementation, the plastic-electro-films are arranged on a metal tube, a tube made of insulating material or an insulating rod.

In particular, in the inventive implementation, the metal tube with the plastic-electro-films arranged thereon is also the conductor.

In particular, in the implementation according to the invention, the control electrodes comprise control foils of Al foils, vapor-deposited Al control foils or conductive material layers. It is also possible to use printed metal electrodes or printed or sprayed-on metal layers or conductive material layers as electrodes. For a simple manufacturing process, the single or double control was determined and selected as the electrodes Al foils, evaporated aluminum or a conductive material layer. Thus, either a use of dual or single control is possible. The result is a simple manufacturing process and an automatic production of the inventive implementation with integrated electrodes is also possible.

In particular, in the practice of this invention the plastic-electro-films polyester-electro-films, wherein the polyester-electro-films have a surface roughness of 0.07 microns to 0.5 microns and no inclusions of conductive particles and no defects are present.

In particular, in the inventive implementation, the polyester-electro-films have a thickness of 10 .mu.m to 80 .mu.m, in particular a thickness of 18 .mu.m to 36 .mu.m. The polyester-electro-films may, for. B. have a thickness of 18, 36 or 72 microns.

Another aspect of the present invention relates to an insulation device for a bushing, which has a shrink tube made of an electrically insulating material. The basic active part together with the shrink tube allows a hermetically sealed base-active part without insulator which is synonymous with a dry active part. Also, any mounting position is possible in the inventive insulation.

In particular, the insulation device according to the invention further comprises silicone screens which are applied to the shrink tubing.

In particular, in the case of the insulating device according to the invention, the shrink tube is a fluoroplastic shrink tube, in particular of FEP (fluorinated ethylene polymer). Alternatively, a Viton-E® shrink tubing can be used. The shrink tube is shrunk by heat on the active part during the manufacturing process. The enclosed by the insulating base active part is hermetically sealed by the shrink tube from the environment. Of the Shrink tubing can also be provided with O-rings or with a hot melt on its inside for better sealing.

In particular, in the inventive insulating device, which comprises a carrier tube, polyester films, control electrodes and impregnating agents (gas, eg air, SF ₆ or N ₂ ) or a polymerizable resin hardener system or a low-viscosity insulating liquid and a shrink tube, silicone screens are easy to integrate on the active part. The active part has a surface for the direct application of outer silicone shades for outdoor use.

A further aspect of the present invention relates to a method for producing a leadthrough with a base active part and an insulating device, wherein the base active part comprises a conductor, plastic-electro-foils, control electrodes and a ground electrode, in which a heat-shrinkable tube of an insulating material is arranged around the base active part and shrunk with heat.

In particular, in the process of the invention, the control electrodes and their edges are provided under vacuum with an elastic and low-viscosity insulating liquid, or with an alternative low-viscosity insulating, which crosslinks at a crosslinking temperature of at least 50 ° C. The insulating liquid may have the property that after a heat process, the insulating liquid passes into an elastic state.

Fig. 2

- einen Schnitt durch ein Ausführungsbeispiel einer erfindungsgemässen Durchführung mit einer erfindungsgemässen Isoliereinrichtung.

In the following, the insulating device according to the invention will be described in more detail with reference to the accompanying drawings with reference to an embodiment. It shows:

Fig. 2

- A section through an embodiment of an inventive implementation with an inventive insulation.

Fig. 2 shows a section through an embodiment of an inventive implementation with an inventive insulating device and a control using the example of a transformer outdoor implementation. Line 1 is a potential line (60%) determined by control electrodes 2. A film insulation with plastic-electro-films 3 is located between a conductor 4 at high voltage potential and a ground electrode 5. A base active part 6, which comprises the conductor 4, the Folienisoliereinrichtung with the plastic-electro-films 3, control electrodes 2 and the earth electrode 5 , is hermetically separated from the environment by a shrink tube 8. A prior art nip 508 (see Fig. 1 ) is not available anymore. Likewise, an existing in the prior art insulator 507 (see Fig. 1 ) have been replaced by silicone screens 7 on the shrink tube 8. The high voltage is applied to a terminal 9, and a high voltage electrode 10 has the same potential as the terminal 9. A terminal 11 to the transformer is connected to the high voltage terminal 9 through the conductor 4. The control electrode (earth electrode 5) is connected to a flange 12 and placed at ground potential 13.

Claims (9)

1. Duct with a base active piece (6) and an insulation device, in which the base active piece (6) comprises a conductor (4), plastic electric films (3), control electrodes (2) and an earth electrode (5), characterised in that the insulation device has a shrink hose (8) made from an electrically insulating material which is arranged around the base active piece.
2. Duct according to claim 1, characterised in that the plastic electric films (3), the control electrodes (2) and their edges are provided with a low-viscosity insulating fluid, which has a viscosity between 8 mm²/s and 20 mm²/s at 40°C, with an alternative low-viscosity insulating fluid, which cross-links at a cross-linking temperature of at least 50°C and has a viscosity between 20 mm²/s and 100 mm²/s at 40°C, or with a gas, e.g. air, N₂ or SF₆.
3. Duct according to claim 1 or 2, characterised in that the plastic electric films (3) are arranged on a metal pipe, a pipe made from insulating material or an insulating bar.
4. Duct according to claim 3, characterised in that the metal pipe with the plastic electric films (3) arranged thereupon is simultaneously the conductor (4).
5. Duct according to one of claims 1 to 4, characterised in that the control electrodes (2) comprise control films made from Al films, vapour-coated Al control films or conductive material layers.
6. Duct according to one of claims 1 to 5, characterised in that the plastic electric films (3) comprise polyester electric films, wherein the polyester electric films have a surface roughness of 0.07 µm to 0.5 µm and contain no inclusions of conducting particles and no imperfections.
7. Duct according to claim 6, characterised in that the polyester electric films have a thickness of 10 µm to 80 µm, in particular a thickness of 18 µm to 36 µm.
8. Method for producing a duct with a base active piece (6) and an insulation device, wherein the base active piece (6) comprises a conductor (4), plastic electric films (3), control electrodes (2) and an earth electrode (5), characterised in that a shrink hose (8) made from an insulating material is arranged around the base active piece (6) and is shrunk by the application of heat.
9. Method according to claim 8, characterised in that the plastic electric films (3), the control electrodes (2) and their edges are provided under vacuum with a low-viscosity insulating fluid, which has a viscosity between 8 mm²/s and 20 mm²/s at 40°C, with an alternative low-viscosity insulating fluid, which cross links at a cross-linking temperature of at least 50°C and has a viscosity between 20 mm²/s and 100 mm²/s at 40°C, or with a gas, e.g. air, N₂ or SF₆.

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