Coated active component in a high-voltage device and method for increasing the dielectric strength
Patent Information
- Application Number
- EP2023729367
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-06-03
- Filing Date
- 2023-05-26
- Publication Date
- 2025-04-09
AI Technical Summary
High-voltage devices face challenges in achieving cost-effective and material-saving dielectric strength, especially when using environmentally friendly insulating gases like clean air or synthetic air, which have poorer electrical insulation properties compared to SF6, leading to potential electrical flashovers and component damage.
Coating active components in high-voltage devices with polymers such as PTFE, PCTFE, or ETFE to provide effective electrical insulation, allowing for the use of alternative insulating gases at lower pressures and enabling compact structures without electrical flashovers.
The polymer coating effectively prevents electrical flashovers, ensuring reliable operation at high voltages while reducing material and cost requirements, even with insulating gases like clean air, thereby enhancing dielectric strength and preventing component damage.
Smart Images
Figure 1.1
Abstract
Description
[0001] Description
[0002] Coated active component in a high-voltage device and method for increasing the dielectric strength
[0003] The invention relates to a high-voltage device, in particular a measuring transformer, with an encapsulating housing and with at least one active component which is arranged in the encapsulating housing, and to a method for increasing the dielectric strength in a high-voltage device.
[0004] High-voltage devices include, for example, instrument transformers, in particular current transformers, voltage transformers and / or combination transformers, as known, for example, from EP 0 236 974 B1. The instrument transformers are designed to measure currents in the range of up to several thousand amperes and / or voltages of up to several hundred kilovolts. Active components are arranged in a housing or encapsulation housing, which, for example, comprises an insulator, in particular a ribbed ceramic and / or silicone insulator. Active components are electrically conductive components which, in the case of an instrument transformer, are surrounded by an electric field during operation. To prevent electrical arcing between active components and / or between the housing and / or the housing, the housing is gas-tight and is filled on the inside with an insulating gas, e.g. SF6.
[0005] SF6 is an insulating gas with good electrical insulating properties, but it is harmful to the environment. SF6 has a very high global warming potential, e.g., 23,500 times higher than CCf. Air, especially purified, dry air, referred to below as clean air and / or synthetic air, is climate-neutral and therefore environmentally friendly. However, the electrical insulating properties of clean air are worse than those of SF6. The use of SF6 involves high costs associated with a gas-tight design of high-voltage equipment. The use of clean air involves high costs associated with designing high-voltage equipment for very high pressures and / or large distances between active components and / or the housing.
[0006] 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 that solves the problems described above. In particular, the object is to provide a high-voltage device that enables high voltage levels in a cost-effective and material-saving manner, particularly when using alternative insulating gases such as clean air or synthetic air, while maintaining high dielectric strength, particularly when using insulating gases with low gas pressures, e.g., in the ambient air range, and / or a compact design, particularly with dimensions similar to those of SF6-filled devices.
[0007] The specified object is achieved according to the invention by a high-voltage device having the features according to claim 1 and / or by a method for increasing the dielectric strength in a high-voltage device, in particular a high-voltage device as described above, 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 a high-voltage device as described above, are specified in the subclaims. Subject matter of the main claims can be combined with each other and with features of subclaims, and features of the subclaims can be combined with each other.
[0008] A high-voltage device according to the 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.
[0009] The coating with the at least one polymer enables electrical insulation of the at least one active component from other components. This prevents electrical arcing during operation of the high-voltage device or when voltage is applied to active components, which can lead to damage or even destruction of components. Coating active components with polymers is cost-effective, saves spacing and thus material, and enables high voltage levels. The use of alternative insulating gases, such as clean air or synthetic air, is possible, particularly in compact structures with high dielectric strength. Insulating gases can be used at low gas pressures, e.g.in the ambient air, with a compact design, particularly with dimensions of SF6-filled devices, without electrical flashovers between active components leading to damage and / or destruction of components when high voltage is applied to the high-voltage device.
[0010] The at least one polymer can be formed on the 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 millimeters and / or in the range of one millimeter or more. In contrast to pure lacquer layers, which are applied very thinly to components, thick polymer layers, especially with the thickness described above, have a good electrical insulating effect, thus preventing damage and / or destruction of components when high voltage is applied to the high-voltage device.
[0011] The high-voltage device can comprise a measuring transformer and / or be a measuring transformer, in particular a current transformer, a voltage transformer and / or a combination transformer. With measuring transformers, good electrical insulation is important, particularly when using insulating gases such as clean air or synthetic air, in compact structures and / or with high voltage in order to rule out measuring errors and malfunctions. The encapsulation housing can be partially or completely filled with clean air, in particular dry, purified air, in particular at a pressure in the range of 7 to 15 bar. Clean air has a lower electrical insulating capacity compared, for example, with SF6 as an insulating gas, which means that there is a risk of electrical arcing between active components, in particular when components of the high-voltage device have the same dimensions.Insulation with at least one polymer effectively and cost-effectively prevents electrical arcing between components, particularly when high voltage is applied to the high-voltage device, thereby preventing damage or even destruction of components and / or the high-voltage device.
[0012] The at least one active component can be and / or comprise a current and / or voltage active part, in particular a core shell of a current and / or voltage active part, an electrode, a current-carrying conductor, in particular a primary conductor, and / or a discharge tube. With the active components described above, there is a high risk of electrical arcing, particularly when high voltage is applied, with the disadvantages described above, which makes insulation with a polymer particularly advantageous.
[0013] The at least one polymer can be in the form of a shrink tube, and / or in the form of a dip coating, and / or in the form of a sprayed coating, and / or in the form of a vulcanized coating. Such methods of applying polymers to active components as electrical insulation are simple and cost-effective to produce, with a high insulating and protective effect.
[0014] The at least one polymer can be and / or comprise polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyolefin, and / or ethylene-tetrafluoroethylene copolymer (ETFE), and / or mixtures of these substances. The aforementioned materials exhibit high mechanical stability and high electrical insulation properties, are easy to process or apply as a layer, are long-term stable, and cost-effective. Thus, such materials are well suited as polymers for coating active components, with the advantages described above.
[0015] The at least one active component, in particular a core shell of a current and / or voltage active part and / or a lead-out tube, can be partially coated, particularly externally, with the at least one polymer. Partial coating can save material in areas where electrical arcing is unlikely, and / or areas for electrical contact can be left out of the coating. An external coating can be sufficient to prevent electrical arcing between active components.
[0016] The at least one active component, in particular an electrode and / or a primary conductor, can be completely coated with the at least one polymer. Components such as electrodes and / or primary conductors may be exposed to the risk of electrical arcing across their entire length or width due to an applied voltage, in particular high voltage. Therefore, a complete coating may be necessary to reliably prevent electrical arcing across these active components, with the advantages described above.
[0017] A method according to the invention for increasing the dielectric strength in a high-voltage device, in particular in a previously described high-voltage device, comprises coating at least one active component, which is arranged in an encapsulating housing, in particular filled with clean air, with at least one polymer, in particular by shrinking a shrink tube and / or by dip coating and / or by spray coating and / or by vulcanization, wherein the polymer is applied in particular as polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyolefin and / or ethylene-tetrafluoroethylene copolymer (ETFE).
[0018] The advantages of the method according to the invention for increasing the dielectric strength in a high-voltage device, in particular in a previously described high-voltage device, according to claim 11 are analogous to the previously described advantages of the high-voltage device according to the invention according to claim 1 and vice versa.
[0019] In the following, an embodiment of the invention is shown schematically in the single figure and described in more detail below.
[0020] The
[0021] Figure schematically shows in sectional view a section of a high-voltage device 1 according to the invention, with active components 3, 7, 8, 9, 10, 11, which are coated with insulating layers 5 made of polymer 4.
[0022] The single figure shows a section of a high-voltage device 1 according to the invention in a sectional view. The high-voltage switching device 1 comprises active components 3, in particular a current active part 7, a voltage active part 8, a control electrode 9, a primary conductor 10, and / or a discharge tube 11. The active components 3 are each coated with an insulating layer 5 made of at least one polymer 4.
[0023] The high-voltage device 1 is, for example, a measuring transformer, in particular a current transformer, a voltage transformer and / or a combination transformer. This enables, for example, measurements of 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 the active components 3, in particular an active current part 7, an active voltage part 8, a control electrode 9, a primary conductor 10 and / or a discharge tube 11 are arranged. The encapsulating housing 2 of the high-voltage device 1 is designed, for example, as an insulator, in particular as an externally ribbed ceramic, silicone and / or composite material insulator. Alternatively or additionally, the encapsulating housing 2 is bowl-shaped, e.g. as a metal bowl.
[0024] The encapsulation housing 2 is gas-tight and filled, for example, with clean air as an insulating gas, i.e. purified, dry air. Alternatively, insulating gases such as SF6 or gas mixtures 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, particularly when using SF6, or, for example, in the range from 7 to 15 bar, particularly when using clean air. The use of encapsulation housings 2 filled with clean air, with dimensions of conventional encapsulation housings 2 of SF6 high-voltage devices 1, saves material and costs. Clean air has poorer electrical insulating properties than SF6. In order to reliably prevent electrical flashovers between components, in particular active components 3 and / or the encapsulation housing 2, e.g.Clean air as insulating gas in encapsulation housings 2 with dimensions of SF6 high-voltage devices 1, according to the invention the active components 3 are covered or coated with an insulating layer 5 made of polymer 4.
[0025] The polymer 4 of the insulating layer 5 is, for example, polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), one or more polyolefins and / or ethylene-tetrafluoroethylene copolymer (ETFE) or comprises polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyolefins and / or ethylene-tetrafluoroethylene copolymers (ETFE). These materials have good electrically insulating properties. Other materials include, for example, other plastics. The insulating layer 5 is formed with a layer thickness in the range of 0.5 to 5 millimeters, and / or in the range of one millimeter and greater. In contrast to thin varnish insulation, thick layers are able to ensure sufficient electrical insulation of the active components 3 at high voltages, in particular with long-term stability. The insulating layer 5 is, for example,in the form of a shrink tube, and / or in the form of a dip coating, and / or in the form of a sprayed coating, and / or in the form of a vulcanized coating. Such coatings are simple and cost-effective to implement.
[0026] As shown in the exemplary embodiment of the single figure, an active component 3, e.g. a core shell of a current and / or voltage active part 7, 8, and / or a lead-out tube 11, is partially coated on the outside with the insulating layer 5. An outer, in particular partial coating is sufficient to reliably prevent electrical flashovers between the active components 3. In areas without a coating, contact can be made and / or there is sufficient distance to other active components 3 to prevent electrical flashovers. An electrode 9 and / or a current-carrying conductor, in particular a primary conductor 10, are, for example, completely coated in order to achieve sufficient electrical insulation from other active components 3.The coatings described above are only examples and, depending on the structure of the high-voltage device 1 and the components 3, can also be specifically coated, fully coated and / or only partially coated, in particular with different layer thicknesses.
[0027] The previously described embodiment can be combined with the prior art. For example, high-voltage devices 1 can comprise high-voltage circuit breakers, disconnectors, transformers, arresters, instrument transformers and / or bushings. The invention can be used in dead-tank systems, i.e. with a grounded housing, or in live-tank systems, i.e. with electrical units at high-voltage potential, arranged in an insulator. Insulating layers 5 made of polymer 4 are formed, for example, as a single layer or as a layer stack comprising several layers. The layers can have different permittivity, in particular decreasing permittivity from layer to layer. By applying further insulating layers with different relative permittivity, where, for example, the permittivity of the inner layer is the highest, and each further layer has a lower orwith decreasing permittivity, but with a permittivity always greater than the permittivity of gas, ie greater than 1, a more pronounced homogenization of the electric field can be achieved compared to only one layer, in order to further relieve the dielectric stress on the critical areas.
[0028] List of reference symbols
[0029] 1 high-voltage device
[0030] 2 encapsulation housings
[0031] 3 active component
[0032] 4 Polymer
[0033] 5 Insulating layer
[0034] 6 Clean Air
[0035] 7 Power active part
[0036] 8 Voltage active part
[0037] 9 Electrode, e.g. control electrode
[0038] 10 current-carrying conductor, e.g. primary conductor
[0039] 11 Discharge pipe
[0040] PTFE Polytetrafluoroethylene
[0041] PCTFE Polychlorotrifluoroethylene
[0042] ET FE ethylene-tetrafluoroethylene copolymer
Claims
Patent claims 1. High-voltage device (1) , comprising an encapsulation housing (2) and comprising at least one active component (3) which is arranged in the encapsulation housing (2), characterized in that the at least one active component (3) is coated with at least one polymer (4).
2. High-voltage device (1) according to claim 1, characterized in that the at least one polymer (4) is formed on the at least one component (3) in the form of an insulating layer (5).
3. High-voltage device (1) according to claim 2, characterized in that the insulating layer (5) has a layer thickness in the range of 0.5 to 5 millimeters and / or in the range of one millimeter and greater.
4. High-voltage device (1) according to one of the preceding claims, characterized in that the high-voltage device (1) comprises 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 one of the preceding claims, characterized in that the encapsulation housing (2) is partially or completely filled with Clean Air (6), in particular dry, purified air, especially at a pressure in the range of 7 to 15 bar.
6. High-voltage device (1) according to 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 part (7, 8), in particular a core shell of a current and / or voltage active part (7, 8), an electrode (9), a current-carrying conductor (10), in particular a primary conductor, and / or a discharge tube (11).
7. High-voltage device (1) according to one of the preceding claims, characterized in that the at least one polymer (4) is formed in the form of a shrink tube, and / or in the form of a dip coating, and / or in the form of a sprayed coating and / or in the form of a vulcanization.
8. High-voltage device (1) according to 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 one of the preceding claims, characterized in that the at least one active component (3) , in particular a core shell of a current and / or voltage active part (7, 8) and / or a discharge tube (11) , is partially coated, in particular on the outside, with the at least one polymer (4).
10. High-voltage device (1) according to 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. Method for increasing the dielectric strength in a high-voltage device (1), in particular in a high-voltage device (1) according to any one of claims 1 to 10, characterized in that at least one active component (3), which is arranged in an encapsulation housing (2), in particular filled with clean air (6), is coated with at least one polymer (4), in particular by shrinking a heat shrink tube and / or by dip coating and / or by spray coating and / or by vulcanization, wherein the polymer (4) is in particular polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), poly- olefin and / or ethylene tetrafluoroethylene copolymer (ETFE) is applied.