Improved built-in or add-on parts for medium-voltage switchgear assemblies
A coating of insulating oxides and nitrides on switchgear components addresses moisture permeability issues, maintaining consistent humidity and enabling precise measurements in medium- and high-voltage switchgear.
Patent Information
- Application Number
- PCT/EP2025/050405
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2024-02-14
- Filing Date
- 2025-01-09
- Publication Date
- 2025-08-21
AI Technical Summary
Existing built-in and add-on parts for medium- and high-voltage switchgear made of plastic or cast resin exhibit moisture permeability, leading to moisture penetration and absorption, which is particularly problematic in SF6-free gas-insulated switchgear due to limited installation space.
Applying a coating of electrically insulating oxides and nitrides, such as aluminum oxide, aluminum nitride, zirconium oxide, and silicon dioxide, on the outer surfaces of these parts to form a closed surface barrier, preventing moisture ingress and egress.
The coating maintains consistent humidity conditions within the switchgear, reducing moisture penetration and leakage, ensuring long-term stability and precise measurements in components like insulators, transformers, and measuring probes.
Smart Images

Figure EP2025050405_21082025_PF_FP_ABST
Abstract
Description
[0001] Description
[0002] Improved built-in or add-on parts for medium-voltage switchgear
[0003] The invention relates to improved built-in or add-on parts for medium or high-voltage switchgear, a switch or a medium or high-voltage switchgear with one or more improved built-in and / or add-on parts and a method for producing such improved built-in or add-on parts for medium or high-voltage switchgear.
[0004] Various built-in or add-on parts for medium-voltage or high-voltage switchgear are known from the state of the art, for example supports, sealing elements, bushings, measuring bushings, transformers or measuring probes.
[0005] When installed, these built-in or add-on parts are at least partially in contact with an insulating and / or switching gas.
[0006] Due to their material properties, built-in and / or add-on components made of plastic or cast resin exhibit a certain degree of permeability, permeability, and thus moisture absorption. This is particularly important for sealing materials, electrically insulating sealing materials, and electrically insulating materials such as those used in supports, bushings, measuring bushings, transformers, or measuring probes, as these materials can cause moisture to penetrate or be introduced into switchgear, particularly medium- or high-voltage switchgear. State-of-the-art technology counteracts this risk by using increased amounts of desiccants.
[0007] This is particularly relevant in the context of SF6-free gas-insulated medium- or high-voltage switchgear, since the installation space is more limited than for medium- or high-voltage switchgear with SF6.
[0008] The object of the invention is to provide built-in and / or add-on parts which eliminate the disadvantages of the prior art.
[0009] The problem is solved by independent claims 1 and 11 and the claims dependent on these claims. A first aspect relates to an improved built-in or add-on part for medium-voltage or high-voltage switchgear, wherein the built-in or add-on part is partially - i.e. at least 10%, 20% or 50% based on the volume or based on the area in contact with an insulating and / or switching gas - largely or completely formed with a plastic or cast resin or at least partially or largely or completely consists thereof, and the plastic or cast resin is - at least partially - to be brought into contact with an insulating and / or switching gas, i.e. can be brought into contact or, in other words, is in contact with the insulating and / or switching gas when used as intended in a medium-voltage or high-voltage switchgear, wherein the built-in or add-on part, or at least the plastic or cast resin of the built-in or add-on part,has a coating on the outer surfaces comprising at least one oxide and / or nitride, and the coating forms a closed surface. The fact that the coating has a closed surface means that the outer surface is completely or largely completely covered with the coating, so that the penetration or ingress of moisture into the plastic or the casting resin or the escape of moisture from the plastic or the casting resin is prevented or reduced. The oxide or nitride is preferably electrically insulating and forms a barrier to moisture. The oxide or nitride thus reduces or prevents the penetration or escape of moisture into or from the insert or attachment, or the plastic or the casting resin of the insert or attachment. This is particularly advantageous for sealing elements, feedthroughs, and measuring feedthroughs.This prevents moisture from penetrating the interior of a medium- or high-voltage switchgear through the inserts or attachments, or from sources of moisture entering the switchgear. The coating therefore prevents or reduces the penetration or leakage of moisture. It is particularly advantageous for insulators, transformers, and measuring probes because it reduces or prevents the penetration of moisture into the insert or attachment, as well as the leakage of moisture from the insert or attachment.
[0010] This reduces the ingress of moisture into the medium or high voltage switchgear and also keeps the moisture content in the plastic or cast resin more constant or constant.
[0011] In the case of components passing through the walls of a gas container, the plastic or cast resin is also at least partially in contact with the ambient air.
[0012] The term "plastic" refers in particular to thermosets or thermosets, thermoplastics and elastomers, especially thermosets. In a preferred embodiment, the coating comprises one or more of aluminum oxide, aluminum nitride, zirconium oxide, silicon nitride, and silicon dioxide.
[0013] Particularly preferably, the coating comprises or is formed from one of aluminum oxide, aluminum nitride, zirconium oxide, silicon nitride and silicon dioxide.
[0014] It is also preferred that the coating has a thickness perpendicular to the outer surface of the plastic or casting resin of at least 50 nm or at least 100 nm. It has been found that a thickness of 50 nm or more is sufficient to ensure a closed surface. At the same time, a coating with an oxide or nitride with a thickness of 50 nm or 100 nm is sufficiently flexible and resistant to ensure a sufficiently long service life, in particular a service life of over 20 or over 30 years.
[0015] In particular, it is preferred that the coating has a thickness perpendicular to the outer surface of the plastic or casting resin of at least 200 nm. Such a thickness of at least 200 nm results in a service life of over 20 or over 30 years.
[0016] In particular, it is also preferred that the coating has a thickness perpendicular to the outer surface of the plastic or the casting resin of at least 400 nm.
[0017] It is also preferred that the coating has a thickness perpendicular to the outer surface of the plastic or casting resin of no more than 5000 nm or no more than 500 nm. Such a limitation of the thickness still results in sufficiently high flexibility while maintaining high resistance.
[0018] It is also preferred that the coating be applied to the insert or attachment, or to the plastic or casting resin of the insert or attachment, using atomic layer deposition or molecular layer deposition. CVD processes, among others, are suitable for this purpose.
[0019] It is further preferred that the built-in or attached part is a support, a sealing element, a feedthrough, a measuring feedthrough, a transducer or a measuring probe.
[0020] In particular, it is preferred that the built-in or attached part be an insulator. This is particularly advantageous because the moisture contained in the plastic or cast resin cannot escape through the coating, nor can further moisture penetrate the plastic or cast resin. Thus, the humidity conditions in a medium-voltage or high-voltage switchgear are not altered in the long term by the insulator.
[0021] It is also particularly preferred that the built-in or attached part be a sealing element. A sealing element coated in this way prevents or reduces the penetration of moisture through the seal itself, thus ensuring more consistent humidity conditions in a medium-voltage or high-voltage switchgear.
[0022] It is also particularly preferred that the built-in or attached part be a bushing. A bushing coated in this way prevents or reduces the penetration of moisture into the bushing or the escape of moisture from the bushing itself, thus leading to more constant humidity conditions in a medium-voltage or high-voltage switchgear.
[0023] It is also particularly preferred that the built-in or add-on part is a measuring feedthrough. A measuring feedthrough within the meaning of this application is, in particular, a feedthrough that additionally fulfills one or more measuring functions, for example, a current feedthrough through a grounded switch housing, in particular a gas tank, that enables current or voltage measurements or current and voltage measurements. A measuring feedthrough coated in this way prevents or reduces the penetration of moisture into the measuring feedthrough or the escape of moisture from the measuring feedthrough itself, thus leading to more constant humidity conditions in a medium-voltage or high-voltage switchgear and the measuring feedthrough, which enables more precise measurements, since a change in the humidity in the plastic or cast resin changes the dielectric constant.
[0024] It is also particularly preferred that the built-in or add-on part is a transformer, in particular a transformer for or in a gas chamber of a medium-voltage or high-voltage switchgear. A transformer coated in this way prevents or reduces the penetration of moisture into the transformer or the escape of moisture from the transformer itself, thus leading to more constant humidity conditions in a medium-voltage or high-voltage switchgear and the transformer, enabling more precise measurements.
[0025] In particular, it is also preferred that the built-in or attached part is a measuring probe, in particular a measuring probe for or in a gas chamber of a medium-voltage or high-voltage switchgear. A measuring probe coated in this way prevents or reduces the penetration of moisture into the measuring probe or the escape of moisture from the measuring probe itself, thus leading to more constant humidity conditions in a medium-voltage or high-voltage switchgear and the measuring probe, enabling more precise measurements.
[0026] A second aspect relates to a switch for a medium-voltage or high-voltage switchgear, wherein the switch has one or more improved built-in and / or add-on parts according to one or more embodiments of the first aspect.
[0027] A third aspect relates to a medium-voltage or high-voltage switchgear, wherein the medium-voltage or high-voltage switchgear comprises one or more improved built-in and / or add-on parts according to one or more embodiments of the first aspect.
[0028] A fourth aspect relates to methods for producing improved built-in or add-on parts for medium-voltage or high-voltage switchgear, wherein
[0029] - a pre-assembled built-in or add-on part which has at least an external area made of a plastic or cast resin, or
[0030] - a plastic or cast resin part of the built-in or add-on part is provided, whereby
[0031] - built-in or add-on part, or
[0032] - The plastic or cast resin part of the insert or attachment is provided with a coating using an atomic layer deposition or molecular layer deposition process, wherein the coating comprises an oxide or nitride and wherein the coating forms a closed surface. External areas, within the meaning of this application, also include external surfaces. These external surfaces can be brought into contact with a switching and / or insulating gas, as well as with ambient air.
[0033] It is particularly preferred that fastening elements 107 made of metal are provided with a coating 1000 only in those areas that are not used for electrical contact, alternatively not for electrical and / or thermal contact, and not for connection to other components, for example the gas space or busbars or measuring lines. Areas that are used for electrical contact, alternatively for electrical and / or thermal contact, and / or for connection to other components, for example the gas space or busbars or measuring lines, are particularly preferably covered before the application of the coating or shielded during coating, so that these areas are not provided with a coating. Such covering is preferably realized with caps, wherein the caps are preferably formed from a silicone or a plastic or cast resin.
[0034] Alternatively or additionally, unwanted coatings can also be removed in a post-processing step.
[0035] With regard to the device according to the invention, all statements made above and below regarding the method according to the invention apply accordingly, and vice versa. In particular, the device according to the invention is designed to carry out the method according to the invention in any desired embodiment or a combination of desired embodiments. With regard to the advantages of the device according to the invention, reference is also made to the advantages described for the method according to the invention, and vice versa.
[0036] The invention is explained in more detail below with reference to figures and exemplary embodiments. The specific embodiments of the exemplary embodiments are in no way intended to limit the general design of the method and device according to the invention; rather, individual design features of the exemplary embodiment can be freely combined with one another and with the features described above in any way.
[0037] In the following, the invention is explained in more detail with reference to figures.
[0038] Figure 1: Exemplary schematic representation of a switchgear according to the invention;
[0039] Figure 2: Exemplary schematic perspective representation of a first built-in part according to the invention;
[0040] Figure 3: Exemplary schematic sectional view of a second
[0041] Attachment and installation part;
[0042] Figure 4: Exemplary schematic sectional view of a third embodiment according to the invention
[0043] Attachment and installation part. Figure 1 shows an exemplary schematic representation of a switchgear 1 according to the invention for medium or high voltages, which is also referred to as medium or high voltage switchgear 1 or just switchgear 1, wherein the switchgear 1 has means for operating the switchgear 1 in an operating panel 6 and display elements 4. Medium or high voltage switches (not shown) are arranged in the switchgear 1, which are disconnectors, earthing switches, load switches or circuit breakers or combinations of these. As a rule, at least one medium or high voltage switch is provided per phase, but depending on the application, more series or parallel medium or high voltage switches may also be provided.
[0044] The switchgear is a gas-insulated switchgear 1, in particular an encapsulated gas-insulated switchgear 1.
[0045] Figure 2 shows an exemplary schematic perspective illustration of a first built-in part 100 according to the invention. Built-in parts 100 within the meaning of this disclosure are parts that are to be arranged entirely in a gas space of the switchgear. As an example of such a built-in part 100, a support 101 is shown here. As an example, the support 101 is shown here as cylindrical with a rib structure, but other shapes, in particular a cylindrical-conical shape, are also possible. In the variant shown, the support 101 is formed from a cast resin 105 and optionally has fastening elements 107, for example made of metal. Furthermore, the support 101 has a coating 1000 on the outer surface 110. The coating 1000 is preferably formed from or with a nitride or oxide, particularly preferably from or with one or more of aluminum oxide, aluminum nitride, zirconium oxide, silicon nitride and silicon dioxide.
[0046] Such a coating 1000 preferably has a thickness, or strength, of 50 nm to 5000 nm perpendicular to the outer surface, particularly preferably a thickness of 100 nm to 300 nm, particularly preferably of around 200 nm, 200 nm ± 50 nm.
[0047] Figure 3 shows an exemplary schematic sectional view of a second attachment and installation part 100 according to the invention. Attachments and installation parts 100 within the meaning of this disclosure are parts that are partially arranged in a gas space, such as feedthroughs 102. A feedthrough 102 is to be understood in particular as an attachment and installation part 100 that is led into a partitioned gas space, in particular an encapsulated gas space, wherein one or more lines or one or more conductors 120 are led through the gas space wall, electrically insulated from a gas space wall (not shown).
[0048] The feedthrough 102 has a coating 1000 that completely covers at least the outer surfaces 110 made of plastic or cast resin 105. In the example shown in Figure 3, areas that serve for electrical contact, such as the fastening elements 107 in the electrical conductor 120, are not covered by the coating 1000. Since the conductor 120 itself is formed from a metal, preferably copper or a copper alloy, the fastening element 107 here consists, for example, of a threaded hole.
[0049] The coating 1000 is preferably formed from or with a nitride or oxide, particularly preferably from or with one or more of aluminum oxide, aluminum nitride, zirconium oxide, silicon nitride and silicon dioxide.
[0050] Such a coating 1000 preferably has a thickness, or strength, of 50 nm to 5000 nm perpendicular to the outer surface 110, particularly preferably a thickness of 100 nm to 300 nm, particularly preferably of around 200 nm, 200 nm ± 50 nm.
[0051] The bushing 102 further comprises a further fastening element 130, in particular a weld-on flange or a screw-on flange.
[0052] To shield the electrical conductor 120, a shield 140 is cast or encapsulated in the plastic or cast resin 105.
[0053] Figure 4 shows an exemplary schematic sectional view of a third attachment and installation part 100 according to the invention, a measuring feedthrough 103. A measuring feedthrough 103 is to be understood in particular as an attachment and installation part 100 which is led into a partitioned gas space, in particular an encapsulated gas space, wherein one or more lines or one or more conductors 120 are led through the gas space wall, electrically insulated from a gas space wall (not shown), and the measuring feedthrough 103 further provides means for measuring parameters. Parameters are preferably an electrical current or an electrical voltage or a temperature or a humidity or a gas pressure or a gas partial pressure or a gas concentration or a gas composition or several of the above parameters.
[0054] The measuring feedthrough 103 has a coating 1000 that completely covers at least the outer surfaces 110 made of plastic or cast resin 105. In the example shown in Figure 3, areas that serve for electrical contact, such as the fastening elements 107 in the electrical conductor 120, are not covered by the coating 1000. Since the conductor 120 itself is formed from a metal, preferably copper or a copper alloy, the fastening element 107 here consists, for example, of a threaded hole.
[0055] The coating 1000 is preferably formed from or with a nitride or oxide, particularly preferably from or with one or more of aluminum oxide, aluminum nitride, zirconium oxide, silicon nitride, and silicon dioxide. This coating prevents moisture from penetrating the plastic or the casting resin 105, on the one hand, and also from escaping from the plastic or the casting resin 105, on the other. This ensures that the humidity in the gas space of a medium- or high-voltage system 1 does not change due to moisture absorption or release by the plastic or the casting resin 105, and that the humidity in the measuring feedthrough 103 does not change due to moisture absorption or release by the plastic or the casting resin 105, which could also change the dielectric constant and thus the measurement properties.
[0056] Such a coating 1000 preferably has a thickness or strength of 50 nm to 5000 nm perpendicular to the outer surface 110, particularly preferably a thickness of 100 nm to 300 nm, particularly preferably of around 200 nm, 200 nm ± 50 nm.
[0057] The measuring feedthrough 103 further comprises an additional fastening element 130, in particular in the form of a weld-on flange or a screw-on flange. This additional fastening element 130 optionally has the coating 1000, which can be partially removed before assembly. Alternatively, and not shown, the fastening element 130 is uncoated in the areas intended for welding.
[0058] The measurement feedthrough 103 further comprises a measuring device 142, which optionally also serves as a shield for the electrical conductor 120. A signal tap 144 is provided for tapping a measurement signal, wherein the signal tap is optionally partially encapsulated or encapsulated in the plastic or cast resin 105. The measuring device 142 is preferably completely encapsulated or encapsulated in the plastic or cast resin 105.
[0059] Regardless of the grammatical gender of a particular term, persons with male, female or other gender identities are included.
[0060] Regardless of the grammatical term usage, individuals with male, female or other gender identities are included within the term.
[0061] List of reference symbols
[0062] 1 switchgear for medium or high voltages, also referred to as medium or high voltage switchgear or just switchgear;
[0063] 4 display element;
[0064] 6 control panel;
[0065] 100 built-in or add-on part;
[0066] 101 supporters;
[0067] 102 Implementation;
[0068] 103 Measurement procedure;
[0069] 105 plastic or cast resin;
[0070] 107 metal fastener;
[0071] 110 Outer surface of the built-in or attached part 100;
[0072] 120 conductors, in particular electrical and / or thermal conductors;
[0073] 130 further fastening element, in particular a weld-on flange or a screw-on flange;
[0074] 140 umbrella 140;
[0075] 142 measuring device;
[0076] 144 signal tap;
[0077] 1000 coating on a built-in or attached part 100.
Claims
Patent claims 1. Improved built-in or add-on part (100) for medium voltage or High-voltage switchgear (1), wherein the built-in or add-on part (100) is formed partially, largely or completely with a plastic or cast resin (105) and the plastic or cast resin (105) is to be brought at least partially into contact with an insulating and / or switching gas, characterized in that the plastic or cast resin (105) has a coating (1000) on outer surfaces (110) which has at least one oxide or nitride and wherein the coating (1000) forms a closed surface.
2. Insert or add-on part (100) according to claim 1, characterized in that the coating (1000) comprises one or more of aluminum oxide, aluminum nitride, zirconium oxide, silicon nitride and silicon dioxide.
3. Insert or add-on part (100) according to claim 1 or 2, characterized in that the coating (1000) has a thickness perpendicular to the outer surface (110) of the plastic or the casting resin (105) of at least 50 nm or at least 100 nm.
4. Insert or add-on part (100) according to claim 3, characterized in that the coating (1000) has a thickness perpendicular to the outer surface (110) of the plastic or the casting resin (105) of at least 200 nm.
5. Insert or add-on part (100) according to claim 3, characterized in that the coating (1000) has a thickness perpendicular to the outer surface (110) of the plastic or the casting resin (105) of at least 400 nm.
6. Insert or add-on part (100) according to one of the preceding claims, characterized in that the coating (1000) has a thickness perpendicular to the outer surface (110) of the plastic or the casting resin (105) of a maximum of 5000nm or a maximum of 500nm.
7. Insert or add-on part (100) according to one of the preceding claims, characterized in that the coating (1000) is applied by means of atomic layer deposition or molecular layer deposition on the insert or add-on part (100) or the plastic or the casting resin (105) of the insert or add-on part (100).
8. Insert and attachment part (100) according to one of the preceding claims, characterized in that the insert or attachment part (100) is a support (101), a sealing element, a bushing (102), a measuring bushing (103), a transducer or a measuring probe.
9. Switch for a medium-voltage or high-voltage switchgear (1), characterized in that the switch has one or more improved built-in and / or add-on parts (100) according to one of the preceding claims.
10. Medium-voltage or high-voltage switchgear (1), characterized in that the medium-voltage or high-voltage switchgear (1) has one or more improved built-in and / or add-on parts (100) according to one of the preceding claims.
11. Method for producing improved built-in or add-on parts for medium-voltage or high-voltage switchgear (1), wherein - a pre-assembled built-in or add-on part (100) which has at least outer regions made of a plastic or cast resin (105), or - a plastic or cast resin part of the built-in or add-on part (100) is provided, characterized in that: - built-in or add-on part (100), or - Plastic or cast resin part of the built-in or add-on part (100) is provided with a coating (1000) by means of a method for atomic layer deposition or molecular layer deposition, wherein the coating (1000) comprises an oxide or nitride and wherein the coating (1000) forms a closed surface.
Citation Information
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