Improved built-in or add-on parts for medium-voltage switchgear

Abstract

The invention relates to an 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 casting resin (105) and the plastic or casting resin (105) is to be brought at least partially into contact with an insulating and / or switching gas, wherein the plastic or casting resin (105) has a coating (1000) on outer surfaces (110) which comprises at least one oxide or nitride and wherein the coating (1000) forms a closed surface, wherein the coating (1000) has a thickness perpendicular to the outer surface (110) of the plastic or casting resin (105) of at most 5000 nm.

Description

[0001] 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.

[0002] Various built-in or add-on components for medium-voltage or high-voltage switchgear are known from the state of the art, such as supports, sealing elements, bushings, measuring bushings, transformers, or measuring probes. These built-in or add-on components are at least partially in contact with an insulating and / or switching gas when installed.

[0003] Due to the nature of the material, built-in and / or add-on components made of plastic or cast resin exhibit a certain degree of permeability, permeability, and thus also moisture absorption. This is particularly important for sealing materials, electrically insulating sealing materials, and electrically insulating materials such as those used in insulators, 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 an increased amount of desiccant. This is particularly relevant in the context of SF6-free gas-insulated medium- or high-voltage switchgear, as installation space is more limited than with medium- or high-voltage switchgear using SF6.

[0004] High-voltage systems are known from DE 44 46 944 A1 which have parts coated with a layer of lacquer containing, for example, aluminium oxide, which is at least 50µm thick.

[0005] DE 100 20 263 A1 discloses insulating components for SF6-insulated switchgear with reinforcing materials for better resistance to, for example, hydrofluoric acid.

[0006] The object of the invention is to provide built-in and / or add-on parts which eliminate the disadvantages of the prior art.

[0007] The problem is solved by the independent claims 1 and 11 and the claims dependent on these claims.

[0008] 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 consists at least partially, largely or completely 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 its outer surfaces,which comprises at least one oxide and / or nitride, and wherein the coating forms a closed surface and the coating has a thickness perpendicular to the outer surface of the plastic or the casting resin of a maximum of 5000 nm. 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 the nitride is preferably electrically insulating and forms a barrier to moisture. The oxide or the 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,Bushings and measuring bushings, as it prevents the penetration of moisture through the built-in or attached parts into the interior of a medium- or high-voltage switchgear, or the introduction of moisture sources into a medium- or high-voltage 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 built-in or attached part and the leakage of moisture from the built-in or attached part.

[0009] 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.

[0010] 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.

[0011] The term plastic refers in particular to thermosets or duromers, thermoplastics and elastomers, especially thermosets.

[0012] 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 leads to 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 maximum thickness of 500 nm perpendicular to the outer surface of the plastic or casting resin. Such a limitation of the thickness 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, by means of 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 add-on component 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 constant 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 compartment 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 add-on 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 - a pre-assembled built-in or add-on part which has at least an external area made of a plastic or cast resin, or - a plastic or cast resin part of the built-in or add-on part is provided, whereby - built-in or add-on part, or - Plastic or cast resin part of the built-in or add-on part is provided with a coating by means of 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 regions, 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.

[0029] 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.

[0030] Alternatively or additionally, unwanted coatings can also be removed in a post-processing step.

[0031] 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.

[0032] 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.

[0033] The invention is explained in more detail below with reference to figures. Fig. 1: Exemplary schematic representation of a switchgear according to the invention; Fig. 2: Exemplary schematic perspective representation of a first built-in part according to the invention; Fig. 3: Exemplary schematic sectional view of a second attachment and installation part according to the invention; Fig. 4: Exemplary schematic sectional view of a third attachment and installation part according to the invention.

[0034] The Fig. 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 simply switchgear 1, wherein the switchgear 1 has means for operating the switchgear 1 in a control 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 thereof. As a rule, at least one medium or high-voltage switch is provided per phase; however, depending on the application, more series or parallel medium or high-voltage switches may also be provided. The switchgear 1 is a gas-insulated switchgear 1, in particular an encapsulated gas-insulated switchgear 1.

[0035] The Fig. 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.

[0036] 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.

[0037] The Fig. 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).

[0038] The feedthrough 102 has a coating 1000 which completely covers at least the outer surfaces 110 made of plastic or cast resin 105. In the example shown, the Fig. 3 Areas that serve for electrical contact, such as the fastening elements 107 in the electrical conductor 120. 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.

[0039] 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.

[0040] 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.

[0041] The bushing 102 further comprises a further fastening element 130, in particular a weld-on flange or a screw-on flange.

[0042] To shield the electrical conductor 120, a shield 140 is cast or encapsulated in the plastic or cast resin 105.

[0043] The Fig. 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.

[0044] The measuring leadthrough 103 has a coating 1000 which completely covers at least the outer surfaces 110 made of plastic or cast resin 105. In the example shown, the Fig. 3 Areas that serve for electrical contact, such as the fastening elements 107 in the electrical conductor 120. 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.

[0045] 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 moisture 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.

[0046] 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.

[0047] 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 not coated in the areas intended for welding.

[0048] 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. List of reference symbols 1 switchgear for medium or high voltages, also referred to as medium or high voltage switchgear or just switchgear; 4 display element; 6 control panel; 100 built-in or add-on part; 101 supporters; 102 Implementation; 103 Measurement procedure; 105 plastic or cast resin; 107 Metal fastener; 110 Outer surface of the built-in or attached part 100; 120 conductors, in particular electrical and / or thermal conductors; 130 further fastening element, in particular a weld-on flange or a screw-on flange; 140 umbrella 140; 142 measuring device; 144 signal tap; 1000 coating on a built-in or add-on part 100.

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, wherein 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 characterized by 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. [2] Insert or add-on part (100) according to claim 1, characterized by that the coating (1000) comprises one or more of aluminum oxide, aluminum nitride, zirconium oxide, silicon nitride and silicon dioxide. [3] Insert or attachment part (100) according to claim 1 or 2, characterized by that the coating (1000) has a thickness perpendicular to the outer surface (110) of the plastic or the casting resin (105) of at least 50nm or at least 100nm. [4] Insert or add-on part (100) according to claim 3, characterized by that the coating (1000) has a thickness perpendicular to the outer surface (110) of the plastic or the casting resin (105) of at least 200nm. [5] Insert or add-on part (100) according to claim 3, characterized by that the coating (1000) has a thickness perpendicular to the outer surface (110) of the plastic or the casting resin (105) of at least 400nm. [6] Insert or add-on part (100) according to one of the preceding claims, characterized by 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 500 nm. [7] Insert or add-on part (100) according to one of the preceding claims, characterized by that the coating (1000) is applied by means of atomic layer deposition or molecular layer deposition to the built-in or add-on part (100) or the plastic or the casting resin (105) of the built-in or add-on part (100). [8] Insert and attachment part (100) according to one of the preceding claims, characterized by that the built-in or add-on part (100) is a support (101), a sealing element, a feedthrough (102), a measuring feedthrough (103), a transducer or a measuring probe. [9] Switch for a medium-voltage or high-voltage switchgear (1), characterized by 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 by 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 by that: - built-in or add-on part (100), or - the plastic or cast resin part of the built-in or add-on part (100) is provided with a coating (1000) by means of a process 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.

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