Coated active component in high voltage device and method for increasing dielectric strength

Abstract

The invention relates to a high-voltage device (1), in particular a measuring transformer, comprising an encapsulation housing (2) and at least one active component (3) arranged in the encapsulation housing (2). The at least one active component (3) is coated with at least one polymer (4). The method according to the invention for increasing the dielectric strength in a high-voltage device (1) comprises at least one active component (3) which is arranged in an encapsulation housing (2), in particular filled with clean air (6), in particular coated by a shrink-fit shrink tube and / or by immersion bath and / or by spray coating with at least one polymer (4), wherein the polymer (4) is applied in particular as polytetrafluoroethylene (PTFE), polyvinyl chloride fluoride (PCTFE), polyolefin and / or ethylene tetrafluoroethylene copolymer (ETFE).

Description

Technical Field

[0001] The invention relates to a high-voltage device, in particular a measuring transformer, comprising an encapsulating housing and at least one active component arranged in the encapsulating housing, and to a method for increasing the dielectric strength in the high-voltage device. Background Art

[0002] The high-voltage device is, for example, a measuring transformer, in particular a current transformer, a voltage transformer and / or a combined transformer, as is known, for example, from EP 0 236 974 B1. The measuring transformer is configured for measuring currents up to several thousand amperes and / or voltages up to several hundred kilovolts. The active components are arranged in a housing or an encapsulating housing, which comprises, for example, an insulator, in particular a ribbed ceramic and / or silicone insulator. The active components are conductive components which are surrounded by an electric field when operating in the measuring transformer. In order to prevent arcs between the active components and / or between the active components and the housing, the housing is configured to be gastight and filled with an insulating gas, for example SF6, on the inside.

[0003] SF6 is an insulating gas with good electrical insulation properties, which is harmful to the environment. SF6 has a high global warming potential, for example 23500 times higher than CO2. Air, in particular pure dry air, hereinafter referred to as clean air and / or synthetic air, is climate neutral and therefore environmentally friendly. However, the electrical insulation properties of clean air are worse than those of SF6. When using SF6, high costs are associated with a gas-tight embodiment of the high-voltage device. When using clean air, high costs are associated with the configuration of the high-voltage device for very high pressures and / or large distances between active components and / or between active components and the housing. Summary of the invention

[0004] The object of the present invention is to provide a high voltage device and a method for increasing the dielectric strength in a high voltage device, which solves the above-mentioned problems. In particular, the object of the present invention is to provide a high voltage device which allows to achieve high voltage levels in a cost-effective and material-saving manner, in particular when using alternative insulating gases (e.g. clean air or synthetic air), at high dielectric strength, in particular when using insulating gases with low gas pressure (e.g. in the range of ambient air), and / or a compact design, in particular with the dimensions of an SF6-filled device.

[0005] According to the invention, the object is achieved by a high-voltage device having the features according to claim 1 and / or a method for increasing the dielectric strength in a high-voltage device, in particular in such a high-voltage device, according to claim 11. Advantageous embodiments of the high-voltage device according to the invention and / or of the method according to the invention for increasing the dielectric strength in a high-voltage device, in particular in such a high-voltage device, are specified in the dependent claims. In this case, the features of the main claim can be combined with one another and with the features of the dependent claims, and the features of the dependent claims can be combined with one another.

[0006] The high-voltage device according to the present invention comprises an encapsulating housing and at least one active component arranged in the encapsulating housing. The at least one active component is coated with at least one polymer.

[0007] The coating with at least one polymer allows at least one active component to be electrically insulated with respect to other components. As a result, arc discharges are prevented during operation of the high-voltage device or when voltage is applied to the active components, which arc discharges can lead to damage or even destruction of the components. Coating the active components with polymers is cost-effective, saves distances and materials, where high voltage levels are possible. At high dielectric strength, alternative insulating gases can be used, such as clean air or synthetic air, in particular in compact structures. The insulating gas can be used at low gas pressures, for example in the range of ambient air, in compact structures, in particular with the size of SF6-filled devices, and when high voltages are applied to the high-voltage device, there are no arcs between the active components leading to damage and / or destruction of the components.

[0008] At least one polymer can be formed on at least one component in the form of an insulating layer. The insulating layer can have a layer thickness in the range of 0.5 to 5 mm and / or in the range of 1 mm and above. Compared to a pure lacquer coating applied very thinly to the component, a thick polymer layer, in particular a thick polymer layer with the above thickness, has a good electrical insulation effect, thereby preventing damage and / or destruction of the component when a high voltage is applied to the high-voltage device.

[0009] High-voltage equipment can include measuring transformers and / or measuring transformers, in particular current transformers, voltage transformers and / or combination transformers. In the case of measuring transformers, good electrical insulation is important in order to exclude measurement errors and faults in a compact structure and / or at high voltages, in particular when using insulating gases such as clean air or synthetic air.

[0010] The encapsulating housing can be partially or completely filled with clean air, in particular dry purified air, in particular air at a pressure in the range of 7 to 15 bar. Compared to, for example, SF6 as an insulating gas, clean air has a lower electrical insulation capacity, as a result of which, in particular in the case of components of the high-voltage device of equal size, there is a risk of arc discharge, in particular between active components. In this case, the insulating material comprising at least one polymer effectively and cost-effectively prevents arcs between the components, in particular when high voltages are applied to the high-voltage device, as a result of which damage or even destruction of the components and / or the high-voltage device is prevented.

[0011] At least one active component may be and / or include a current and / or voltage active component, in particular a core housing, an electrode, a conductor through which current flows, in particular a primary conductor, and / or a discharge tube of a current and / or voltage active component. In the case of the above-mentioned active components, there is a high risk of arc discharge, in particular when high voltages are applied, with the above-mentioned disadvantages, so insulation with polymers has a particularly advantageous effect.

[0012] At least one polymer can be configured in the form of a shrink tube and / or in the form of a dip coating and / or in the form of a spray coating and / or in the form of a vulcanization. This method of applying a polymer to an active component, such as electrical insulation, can be easily and cost-effectively produced with a high insulating or protective effect.

[0013] At least one polymer may be and / or include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyolefins and / or ethylene tetrafluoroethylene copolymers (ETFE) and / or mixtures of these substances. The above-mentioned materials exhibit high mechanical stability and a high electrical insulating effect, can be easily processed and / or applied as a layer, are stable in the long term, and are cost-effective. Therefore, this material is very suitable as a polymer for coating active components, having the above-mentioned advantages.

[0014] At least one active component, in particular the core housing and / or the discharge vessel of a current and / or voltage active component, can be partially, in particular on the outside, coated with at least one polymer. The partial coating makes it possible to save material in areas where arcing is not possible and / or areas for electrical contacting can save material from the coating. The outer coating is sufficient to prevent arcing between the active components.

[0015] At least one active component, in particular an electrode and / or a primary conductor, can be completely coated with at least one polymer. In the case of components such as electrodes and / or primary conductors, due to the applied voltages, in particular high voltages, the risk of arcing may exist over their entire length or width, so that in order to reliably prevent arcing on said active component, a full coating may be required, with the above-mentioned advantages.

[0016] The method according to the invention for increasing the dielectric strength in a high-voltage device, in particular in the above-mentioned high-voltage device, comprises at least one active component which is arranged in an encapsulating housing, in particular filled with clean air, and coated with at least one polymer, in particular by shrinking on a shrink tube and / or by dipping and / or by spraying and / or by vulcanization, wherein the polymer is applied in particular as polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyolefin and / or ethylene tetrafluoroethylene copolymer (ETFE).

[0017] The advantages of the method according to the invention for increasing the dielectric strength in a high-voltage device, in particular the above-mentioned high-voltage device according to claim 11, are similar to the above-mentioned advantages of the high-voltage device according to the invention according to claim 1 and vice versa.

[0018] An embodiment of the invention will be schematically shown in one of the following figures and will be described in more detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In this case, the

[0020] The figure is a schematic cross-sectional view of a detail of a high-voltage device 1 according to the invention comprising active components 3 , 7 , 8 , 9 , 10 , 11 coated with an insulating layer 5 made of a polymer 4 . DETAILED DESCRIPTION

[0021] The figure is a cross-sectional view of a detail of a high-voltage device 1 according to the invention. The high-voltage device 1 comprises active components 3, in particular current active components 7, voltage active components 8, control electrodes 9, primary conductors 10 and / or discharge vessels 11. The active components 3 are each coated with an insulating layer 5 made of at least one polymer 4.

[0022] The high-voltage device 1 is, for example, a measuring transformer, in particular a current transformer, a voltage transformer and / or a combined transformer. Thus, for example, it is possible to measure voltages in the range of up to several hundred kilovolts (i.e., high voltages) and / or currents in the range of up to several thousand amperes. The high-voltage device 1 comprises an encapsulating housing 2, inside which active components 3 are arranged, in particular current active components 7, voltage active components 8, control electrodes 9, primary conductors 10 and / or discharge tubes 11. The encapsulating housing 2 of the high-voltage device 1 is, for example, configured as an insulator, in particular a ceramic, silicone and / or composite insulator with ribs on the outside. Alternatively or additionally, the encapsulating housing 2 is configured in the shape of a pot, for example a metal pot.

[0023] The encapsulation shell 2 is configured to be airtight and is filled with, for example, clean air as an insulating gas, i.e., purified dry air. Alternatively, an insulating gas such as SF6 or a gas mixture can be used. The pressure of the insulating gas is, for example, equal to the ambient pressure, i.e., 1 bar, or up to 6 bar, in particular when SF6 is used, or, for example, in the range of 7 to 15 bar, in particular when clean air is used. The use of an encapsulation shell 2 filled with clean air and having the size of a conventional encapsulation shell 2 of an SF6 high-voltage device 1 saves material and costs. The electrical insulation properties of clean air are worse than those of SF6. In order to reliably prevent arcs between components, in particular between active components 3 and / or the encapsulation shell 2, for example, in the case of clean air as an insulating gas in an encapsulation shell 2 having the size of an SF6 high-voltage device 1, according to the present invention, the active component 3 is covered or coated with an insulating layer 5 made of a polymer 4.

[0024] The polymer 4 of the insulating layer 5 is, for example, polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), one or more polyolefins and / or ethylene tetrafluoroethylene copolymers (ETFE), or comprises polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyolefins and / or ethylene tetrafluoroethylene copolymers (ETFE). These materials show good electrical insulation properties. Other materials are, for example, other plastic materials. The insulating layer 5 is configured to have a layer thickness in the range of 0.5 to 5 mm and / or 1 mm and above. Compared with thin lacquer insulation, thick layers can ensure sufficient electrical insulation of the active component 3 under high voltage, particularly in a long-term stable manner. The insulating layer 5 is, for example, configured in the form of a shrink tube and / or a dip-coated form, and / or a vulcanized form. This coating can be easily and cost-effectively produced.

[0025] As shown in the embodiment of the figure, active components 3, such as core housings or current and / or voltage active components 7, 8 and / or discharge tubes 11, are partially coated with an insulating layer 5 on the outside. The outer coating, in particular a partial coating, is sufficient to reliably prevent arcs between the active components 3. In areas without coating, contacts can occur and / or there is a sufficient distance to other active components 3 to prevent arcs. The electrodes 9 and / or the conductors through which the current flows, in particular the primary conductors 10, are for example completely coated in order to achieve sufficient insulation with respect to the other active components 3. The above-mentioned coatings are only examples and can also be implemented specifically, completely coated and / or only partially coated, in particular with different layer thicknesses, depending on the construction of the high-voltage device 1.

[0026] The above embodiments can be combined with the prior art. Thus, for example, the high-voltage device 1 can include a high-voltage power circuit breaker, a disconnect switch, a transformer, a surge arrester, a measuring transformer and / or a gasket. The invention can be used for a dead tank system, i.e. a system with a grounded housing, or for a live tank system, i.e. a system with an electrical unit at a high voltage potential arranged in an insulator.

[0027] The insulating layer 5 made of polymer 4 is configured, for example, as a stack of one or more layers. In this case, the layers can have different dielectric constants, in particular a dielectric constant that decreases from layer to layer. The application of further insulating layers of different relative dielectric constants, where for example the dielectric constant of the inner layer is the highest and each further layer is configured to have a lower or decreasing dielectric constant, but always with a dielectric constant that is greater than that of the gas, i.e. greater than 1, makes it possible to achieve a more significant homogenization of the electric field compared to only one layer, thereby further dielectrically releasing critical areas.

[0028] Reference Numbers List:

[0029] 1 High voltage equipment

[0030] 2 Package shell

[0031] 3 Active components

[0032] 4 Polymer

[0033] 5 Insulation layer

[0034] 6. Clean Air

[0035] 7 Current active components

[0036] 8 Voltage active components

[0037] 9 Electrodes, such as control electrodes

[0038] 10Conductor through which current flows, such as the primary conductor

[0039] 11 Discharge tube

[0040] PTFE Polytetrafluoroethylene

[0041] PCTFE Polychlorotrifluoroethylene

[0042] ETFE Ethylene Tetrafluoroethylene

Claims

1. A high voltage device (1), comprising an encapsulating housing (2) and at least one active component (3) arranged in the encapsulating housing (2), characterized in that: The at least one active component (3) is coated with at least one polymer (4).

2. The high voltage device (1) according to claim 1, characterized in that The at least one polymer (4) is formed in the form of an insulating layer (5) on the at least one component (3).

3. The high voltage device (1) according to claim 2, characterized in that The layer thickness of the insulating layer (5) is in the range of 0.5 to 5 mm and / or in the range of 1 mm and above.

4. High-voltage device (1) according to any one of the preceding claims, characterized in that The high-voltage device (1) comprises a measuring transformer and / or is a measuring transformer, in particular a current transformer, a voltage transformer and / or a combined transformer.

5. High-voltage device (1) according to any one of the preceding claims, characterized in that The encapsulating housing (2) is partially or completely filled with clean air (6), in particular dry purified air, in particular air at a pressure in the range of 7 to 15 bar.

6. High-voltage device (1) according to any one of the preceding claims, characterized in that The at least one active component (3) is and / or comprises a current and / or voltage active component (7, 8), in particular a core shell of the current and / or voltage active component (7, 8), an electrode (9), a conductor (10) through which current flows, in particular a primary conductor, and / or a discharge tube (11).

7. High-voltage device (1) according to any one of the preceding claims, characterized in that The at least one polymer (4) is configured in the form of a shrink tube, and / or in the form of a dip coating, and / or in the form of a spray coating, and / or in the form of a vulcanization.

8. High-voltage device (1) according to any one of the preceding claims, characterized in that The at least one polymer (4) is and / or comprises polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyolefin and / or ethylene tetrafluoroethylene copolymer (ETFE).

9. High-voltage device (1) according to any one of the preceding claims, characterized in that The core housing and / or the discharge vessel (11) of the at least one active component (3), in particular a current and / or voltage active component (7, 8), is partially, in particular on the outside, coated with the at least one polymer (4).

10. High voltage device (1) according to any one of the preceding claims, characterized in that The at least one active component (3), in particular an electrode (9) and / or a primary conductor (10), is completely coated with the at least one polymer (4).

11. A method for increasing the dielectric strength in a high voltage device (1), in particular a method for increasing the dielectric strength in a high voltage device (1) according to any one of claims 1 to 10, characterized in that At least one active component (3) arranged in an encapsulation housing (2) which is in particular filled with clean air (6) is coated with at least one polymer (4), in particular by shrinking on a shrink tube and / or by dipping and / or by spraying and / or by vulcanization, wherein the polymer (4) is in particular applied as polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyolefin and / or ethylene tetrafluoroethylene copolymer (ETFE).

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