WO2023280413A1

WO2023280413A1 - Insulator assembly, gas-insulated system and method for assembling gas-insulated system

Info

Publication number: WO2023280413A1
Application number: PCT/EP2021/069071
Authority: WO
Inventors: Luopeng LIU; Xiuming XU; Dajin CHEN; Wenyong Wang; Longguang CHEN; Jieshen NONG; Tiansong CHEN
Original assignee: Hitachi Energy Switzerland Ag
Priority date: 2021-07-08
Filing date: 2021-07-08
Publication date: 2023-01-12
Also published as: CN218384644U

Abstract

The present disclosure relates to an insulator assembly for a gas-insulated system, a gas-insulated system, and a method for assembling a gas-insulated system. The insulator assembly includes: an insulator including a central portion extending along a central axis and a leg extending from the central portion in a radial direction perpendicular to the central axis; a connecting plate provided at an end of the leg; and an adapter movably mounted to the connecting plate such that the adapter is movable relative to the connecting plate from a preparing position to a fastening position in a direction away from the central portion. The adapter includes a fastening hole for fastening the adapter in the fastening position to an enclosure of the gas-insulated system. The insulator assembly can not only facilitate assembly and avoid scratches on the connecting plate and the enclosure, but also avoid mechanical damage to the insulator during assembly.

Description

INSULATOR ASSEMBLY, GAS-INSULATED SYSTEM AND METHOD FOR ASSEMBLING GAS-INSULATED SYSTEM

TECHNICAL FIELD

[0001] The present invention relates to an insulator assembly for a gas-insulated system, a gas-insulated system, and a method for assembling a gas-insulated system.

BACKGROUND

[0002] Typically, a gas-insulated system includes an enclosure and electrical devices/components. The enclosure may define a closed space filled with insulating gas such as SFe. The electrical devices/components such as circuit breaker, disconnector, and conductive tube may be accommodated in the closed space for safe electrical operations. Common gas-insulated systems include, for example, gas-insulated switchgear (GIS) and gas-insulated transmission line (GIL).

[0003] A gas-insulated transmission line generally includes a hollow cylindrical enclosure, a conductor tube disposed at the center of the enclosure, and an insulator electrically insulating the conductor tube from the enclosure. The insulator is disposed inside the enclosure and supports the conductor tube.

[0004] With respect to the installation of the insulator inside the enclosure, in some existing technical solutions, free ends of the insulator may be directly welded to the enclosure, or may be threadedly connected to the enclosure by connecting plates substantially extending in a circumferential direction of the enclosure and bolts. For the former, welding spatter may contaminate, for example, the insulator, the conductor tube, and an inner surface of the enclosure. Complex measures are needed for avoiding or eliminating such contaminations. For the latter, due to manufacturing tolerances (especially dimensional tolerances and/or shape tolerances of the enclosure, such as roundness tolerances of the enclosure), a gap between the connecting plate and the enclosure is not constant. If the gap is too small, the connecting plate and the enclosure might be scratched during the assembly process, and the bolt holes on the connecting plate and the enclosure might be difficult to align. If the gap is too large, the connecting plate will be forced to deform under a tightening force for the bolt, until the connecting plate contacts the enclosure, which might exert force on the free end of the insulator connected to the connecting plate, and even cause the insulator to be mechanically damaged and deteriorated in insulation performance.

SUMMARY

[0005] In view of the above, the present disclosure aims to provide an insulator assembly for a gas-insulated system, a gas-insulated system, and a method for assembling a gas-insulated system that overcome the defects of the prior art.

[0006] To this end, a first aspect of the present disclosure provides an insulator assembly for a gas-insulated system comprising an insulator comprising a central portion extending along a central axis and a leg extending from the central portion in a radial direction perpendicular to the central axis; a connecting plate provided at an end of the leg; and an adapter movably mounted to the connecting plate such that the adapter is capable of moving relative to the connecting plate from a preparing position to a fastening position in a direction away from the central portion, the adapter comprising a fastening hole for being fastened to an enclosure of the gas-insulated system by a threaded fastener in the fastening position.

[0007] For the insulator assembly according to the first aspect of the present disclosure, the connecting plate can be fastened to the enclosure by a movable adapter. This allows the connecting plate to be separated from the enclosure, thus avoiding the friction between the connecting plate and the enclosure and in turn avoiding scratches on the connecting plate and the enclosure and undesirable particles. Also, it would be easier to adjust the insulator assembly inside the enclosure to align the fastening holes of the adapter and the enclosure.

[0008] Further, the adapter can be moved to a fastening position in a direction away from the central portion, which allows the adapter to be in contact with the enclosure in the fastening position. Thus, when fastening the adapter in the fastening position to the enclosure, the connecting plate would not be subjected to the tightening force of the threaded fastener, preventing the connecting plate from being deformed during fastening.

[0009] According to a preferred embodiment of the present disclosure, the adapter comprises an adapter body defining the fastening hole; the connecting plate comprises a mounting hole extending therethrough; and the adapter body is provided in the mounting hole and threadedly engaged with the mounting hole to allow the adapter to be moved between the preparing position and the fastening position.

[0010] According to a preferred embodiment of the present disclosure, the adapter body comprises a contacting end for contacting the enclosure in the fastening position; the connecting plate comprises a first side surface facing the central portion and a second side surface opposite to the first side surface; and the contacting end of the adapter extends beyond the second side surface when the adapter is in the fastening position. Thereby, when the adapter is in the fastening position, the adapter contacts the enclosure and the connecting plate is separated from the enclosure.

[0011] According to a preferred embodiment of the present disclosure, the adapter further comprises a shielding cover connected with the adapter body at an end of the adapter body, and the shielding cover extends around the adapter body and comprises a curved surface.

[0012] According to a preferred embodiment of the present disclosure, the connecting plate further comprises a connecting hole for connecting a particle trapping member of the gas-insulated system to the connecting plate, and the shielding cover covers the connection hole to avoid point discharge at the joint between the connecting plate and the particle trapping member.

[0013] According to a preferred embodiment of the present disclosure, the connecting plate comprises a plate body and a mounting boss extending substantially perpendicular to the plate body. The mounting boss defines the mounting hole.

[0014] According to a preferred embodiment of the present disclosure, the connecting plate comprises a middle section and a side section adjoining the middle section. The middle section is connected with the end of the leg, and the mounting hole is provided at the side section.

[0015] According to a preferred embodiment of the present disclosure, the connecting plate comprises two side sections on opposite sides of the middle section, and each side section is provided with a mounting hole, so as to stably fasten the insulator to the enclosure.

[0016] According to a preferred embodiment of the present disclosure, a metallic insert is embedded in the end of the leg, and the connecting plate is connected with the metallic insert.

[0017] A second aspect of the present disclosure provides a gas-insulated system comprising an enclosure and an insulator assembly for a gas-insulated system according to the first aspect of the present disclosure. The insulator assembly is provided inside the enclosure; a connecting plate of the insulator assembly is separated from the enclosure; and an adapter of the insulator assembly is separated from the enclosure in a preparing position, and is in contact with the enclosure in a fastening position where the adapter is fastened to the enclosure by a threaded fastener.

[0018] According to a preferred embodiment of the present disclosure, the enclosure comprises a fastening protrusion, and the adapter is fastened to the fastening protrusion by the threaded fastener.

[0019] According to a preferred embodiment of the present disclosure, the enclosure has a cylindrical shape, and the connecting plate extends substantially in a circumferential direction of the enclosure.

[0020] A third aspect of the present disclosure provides a method for assembling a gas-insulated system comprising: providing an enclosure and providing an insulator assembly. The insulator assembly comprises: an insulator comprising a central portion extending along a central axis and a leg extending from the central portion in a radial direction perpendicular to the central axis; a connecting plate provided at an end of the leg; and an adapter movably mounted to the connecting plate such that the adapter is capable of moving relative to the connecting plate from a preparing position to a fastening position in a direction away from the central portion, the adapter comprising a first fastening hole for being fastened to the enclosure by a threaded fastener in the fastening position.

[0021] According to a preferred embodiment of the present disclosure, the method further comprising: moving the adapter to the preparing position; placing the insulator assembly in position inside the enclosure; moving the adapter to the fastening position; and connecting the adapter to the enclosure by the threaded fastener. When the adapter is moved to the fastening position, the connecting plate is separated from the enclosure, and the adapter extends beyond the connecting plate to be in contact with the enclosure.

[0022] According to a preferred embodiment of the present disclosure, the enclosure comprises a second fastening hole, and the method further comprises aligning the first fastening hole with the second fastening hole to place the insulator assembly in position inside the enclosure.

[0023] The insulator assembly for a gas-insulated system, the gas-insulated system, and the method for assembling a gas-insulated system according to the present disclosure can not only facilitate assembly and avoid scratches on the connecting plate and the enclosure, but also prevent the connecting plate from being deformed during fastening process and in turn prevent the connecting plate from pulling the leg of the insulator connected with the connecting plate and causing mechanical damage to the insulator. [0024] Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to “a/an/the element, apparatus, component, means, step, etc.” are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other features and advantages of the present disclosure will be better understood through the following preferred embodiments described in detail with reference to the accompanying drawings, in which the same reference numerals indicate the same or similar components.

[0026] FIG. 1 is a partial perspective view of a gas-insulated system according to an embodiment of the present disclosure;

[0027] FIG. 2 is a sectional view of the gas-insulated system in FIG. 1; [0028] FIG. 3 A is a partial sectional view of the gas-insulated system in FIG. 1, showing an adapter of the gas-insulated system in a preparing position;

[0029] FIG. 3B is another partial sectional view of the gas-insulated system in FIG. 1, showing the adapter of the gas-insulated system in a fastening position;

[0030] FIG. 4 is another sectional view of the gas-insulated system in FIG. 1; [0031] FIG. 5 is a partial perspective view of the gas-insulated system in FIG. 1 with an enclosure of the gas-insulated system omitted;

[0032] FIG. 6 is a perspective view of an insulator of the gas-insulated system in FIG. 1; [0033] FIG. 7A is a perspective view of a connecting plate of the gas-insulated system in FIG. i; [0034] FIG. 7B is a front view of the connecting plate in FIG. 7A;

[0035] FIG. 8 A is a perspective view of the adapter of the gas-insulated system in FIG. 1; and [0036] FIG. 8B is a sectional view of the adapter in FIG. 8A.

DETAILED DESCRIPTION [0037] The implementation and usage of the embodiments are discussed in detail below. However, it should be understood that the specific embodiments discussed are merely intended to illustrate specific ways of implementing and using the present disclosure, and are not intended to limit the protection scope of the present disclosure.

[0038] It should be noted that the drawings not only are used for the explanation and description of the present disclosure, but also are helpful for the definition of the present disclosure when necessary.

[0039] Herein, a gas-insulated system refers to a system/an apparatus that includes a metal enclosure defining closed space(s) filled with insulating gas and electrical devices/components accommodated in the metal enclosure. A GIL will be taken as an example to discuss the insulator assembly for a gas-insulated system, the gas-insulated system, and the method for assembling a gas-insulated system according to the present disclosure. It should be understood that the gas-insulated system according to the present disclosure may be in form of other gas-insulated systems such as a GIS, and the insulator assembly according to the present disclosure may be applied to other gas-insulated systems such as a GIS to support a busbar thereof.

[0040] Referring to FIGS. 1, 2 and 4, a gas-insulated system 100 according to an embodiment of the present disclosure is shown and the gas-insulated system 100 is in form of a GIL. In the illustrated embodiment, the gas-insulated system 100 mainly includes an enclosure 102, a conductive tube 104 accommodated in the enclosure 102 for carrying current, and an insulator assembly 106 for supporting the conductive tube 104 and insulating it from the enclosure 102. Typically, both the enclosure 102 and the conductive tube 104 are long, for example, having a length over 10 meters, such as 18 meters. Thus, one or more insulator assembly 106 is needed to support the conductive tube 104 inside the enclosure 102. For better illustration of the insulator assembly 106, only one insulator assembly 106 and parts of the enclosure 102 and the conductive tube 104 where the insulator assembly 106 is arranged are shown in FIGS. 1, 2 and 4.

[0041] In the illustrated embodiment, the enclosure 102 may have a cylindrical shape. The conductive tube 104 may be arranged inside the enclosure 102 and coaxial with the enclosure 102 with respect to a central axis A. Typically, the enclosure 102 is at a ground electrical potential, and the conductive tube 104 is at a relatively high electrical potential, such as in a range of 100 kV-1200 kV, for example, 550 kV. The enclosure 102 and the conductive tube 104 may be made of metallic materials, such as aluminum, aluminum alloy and copper.

[0042] The insulator assembly 106 is arranged between the enclosure 102 and the conductive tube 104 to support the conductive tube 104 inside the enclosure 102. The insulator assembly 106 includes an insulator 108, connecting plates 110 and adapters 112.

[0043] Referring to FIGS. 4 and 6, the insulator 108 has a central portion 114 extending along the center axis A and legs 116 extending from the central portion 114 in a radial direction perpendicular to the center axis A. The central portion 114 has an annular shape. The central portion 114 may be integrated with a metallic sleeve 122. The metallic sleeve 122 is configured for accommodating the conductive tube 104, and is connected to the conductive tube 104. In the illustrated embodiment, the insulator 108 has three legs 116. The legs 116 may be arranged at an angle of 120° between two adjacent legs 116. Ametallic insert 118 may be embedded in the end 120 of each leg 116 for connecting the insulator 108 to the enclosure 102 by means of a corresponding connecting plate 110. It may be conceived that the insulator 108 may have any suitable number of legs 116, for example, two legs 116. The central portion 114 and the legs 116 may be made of insulating materials, such as epoxy resin. The metallic insert 118 and the metallic sleeve 122 may be made of metallic materials such as aluminum and aluminum alloy.

[0044] Referring to FIGS. 2, 7A and 7B, the connecting plate 110 is provided at the end 120 of the leg 116 and is separated from the enclosure 102.

[0045] In the illustrated embodiment, the connecting plate 110 is connected with the metallic insert 118 by first connectors 126. The connecting plate 110 may extend substantially in a circumferential direction of the enclosure 102. The connecting plate 110 may include a middle section 128 and side sections 130 adjoining the middle section 128. The middle section 128 may be provided with first connecting holes 132 for connecting the connecting plate 110 with the metallic insert 118 by the first connectors 126. In the illustrated embodiment, the middle section 128 has four first connecting holes 132. The side section 130 may be provided with a mounting hole 134 extending therethrough for mounting the adapter 112, and the side section 130 may be fastened to the enclosure 102 by means of the adapter 112. The side section 130 may also be provided with second connecting holes 136 for connecting a particle trapping member 138 to the connecting plate 110 by second connectors 137. In the illustrated embodiment, three particle trapping members 138 and three connecting plates 110 are alternately connected and form a circular shape. In the illustrated embodiment, the side section 130 has one mounting hole 134 and three second connecting holes 136 next to the mounting hole 134. It should be understood that the connecting plate 110 may have any suitable number of first connecting holes 132, mounting holes 134 and second connecting holes 136. The first connectors 126 and second connectors 137 may be in form of bolts or screws.

[0046] In the illustrated embodiment, the connecting plate 110 includes two side sections 130 on opposite sides of the middle section 128, and each side section 130 is provided with one mounting hole 134. In other words, the connecting plate 110 may be fastened to the enclosure 102 by means of two adapters 112. It should be understood that the connecting plate 110 may have any suitable number of side sections 130, for example four side sections 130 arranged around the middle section 128. By connecting the middle section 128 to the leg 116 of the insulator 108 and connecting two or more side sections 130 to the enclosure 102, the leg 116 of the insulator 108 can be stably fastened to the enclosure 102 by the connecting plate 110.

[0047] As shown in FIGS. 2, 7A and 7B, the two side sections 130 and the middle sections 128 each may be a substantially flat plate, and the middle section 128 may form an obtuse angle with each side section 130, such that the connecting plate 110 can substantially follow the inner contour of the enclosure 102. It may be conceived that the middle section 128 and side sections 130 may each have an arc shape to follow the inner contour of the enclosure 102

[0048] The side section 130 may include a plate body 140 and a mounting boss 142 extending substantially perpendicular to the plate body 140. The side section 130 may include a first side surface 144 facing the central portion 114 of the insulator 108 and a second side surface 146 opposite to the first side surface 144. In the illustrated embodiment, the second side surface 146 may be a plane surface. The mounting boss 142 may extend from the plate body 140 towards the central portion 114 in the radial direction perpendicular to the center axis A. The mounting boss 142 may define the mounting hole 134 for mounting the adapter 112.

[0049] Referring to FIGS. 2, 3 A and 3B, the adapter 112 is movably mounted to the connecting plate 110 such that the adapter 112 is capable of moving relative to the connecting plate 110 from a preparing position (see FIG. 3 A) to a fastening position (see FIG. 3B) in a direction away from the central portion 114. The adapter 112 may be made of metallic materials, such as steel.

[0050] Referring to FIGS. 7A to 8B, in the illustrated embodiment, the adapter 112 may include an adapter body 148. The adapter body 148 may be provided in the mounting hole 134 of the connecting plate 110 and threadedly engaged with the mounting hole 134 to allow the adapter body 148 to be moved between the preparing position and the fastening position. Specifically, the adapter body 148 may have an external thread 150 on its outer circumferential surface, and the mounting hole 134 may have a corresponding inner thread 152 on its inner circumferential surface.

[0051] Referring to FIGS. 2, 3A, 3B, 8A and 8B, the adapter body 148 may define a first fastening hole 154 for fastening the adapter 112 in the fastening position to the enclosure 102 by a threaded fastener 156. Accordingly, the enclosure 102 may include a second fastening hole 160 with an inner thread 161. The threaded fastener 156 may be in form of bolt or screw. In the illustrated embodiment, the enclosure 102 may include fastening protrusions 158 which may define the second fastening holes 160. The fastening protrusions 158 may be integrated with the enclosure 102 by welding. The enclosure 102 may have three pairs of fastening protrusions 158 with each pair of fastening protrusions 158 corresponding to two adapters 112 mounted to one connecting plate 110. The threaded fastener 156 may be inserted through the first fastening hole 154 and be screwed into the second fastening hole 160, fastening the adapter 112 to the enclosure 102 and thus fastening the connecting plate 110 and the insulator 108 to the enclosure 102.

[0052] The adapter body 148 may include a contacting end 162 for contacting the enclosure 102 in the fastening position. As shown in FIG. 3 A, when the adapter 112 is in the preparing position, the contacting end 162 of the adapter 112 does not extend beyond the second side surface 146 of the connecting plate 110. For example, the contacting end 162 may be flushed with the second side surface 146, or be recessed relative to the second side surface 146. As shown in FIG. 3B, when the adapter 112 is in the fastening position, the contacting end 162 of the adapter 112 extends beyond the second side surface 146 to be in contact with the fastening protrusion 158 of the enclosure 102.

[0053] As best shown in FIGS. 2, 8A and 8B, the adapter 112 may further include a shielding cover 164 connected with the adapter body 148. The shielding cover 164 may be located at a side of the connecting plate 110 closer to the central portion 114 of the insulator 108. The shielding cover 164 may be provided around the adapter body 148, and cover the second connecting holes 136 and the second connectors 137 in the second connecting holes 136. The shielding cover 164 may include a curved surface 166 which is shaped to prevent charge accumulation at the ends of the threaded fastener 156 and the second connectors 137, thus avoiding point discharge at the joints between the connecting plate 110 and the enclosure 102 and between the connecting plate 110 and the particle trapping member 138.

[0054] In the illustrated embodiment, the shielding cover 164 may be integrated with the adapter body 148. The shielding cover 164 may be located at end of the adapter body 148 opposite to the contacting end 162 and extend around the adapter body 148, such that the adapter 112 generally has an umbrella shape. And when the adapter 112 is mounted to the connecting plate 110, the shielding cover 164 would not interfere with the connecting plate 110. It may be conceived that the shielding cover 164 may be a separate component for avoiding point discharge.

[0055] The method for assembling a gas-insulated system according to an embodiment of the present disclosure will be described referring to FIGS. 1 to 8B.

[0056] First, the connecting plates 110 may be connected to the metallic inserts 118 of the insulator 108 by the first connectors 126, and the particle trapping members 138 may be connected to the connecting plates 110 by second connectors 137. Then, the adapters 112 may be mounted to connecting plates 110 and moved to the preparing position.

[0057] Next, the conductive tube 104 may be fixed to the metallic sleeve 122 of the insulator 108. Then, the conductive tube 104, the insulator assembly 106, and the particle trapping members 138, which have been assembled together, may be moved into the enclosure 102 along the central axis A, and be adjusted such that the first fastening holes 154 of the adapters 112 are aligned with the second fastening holes 160 of the enclosure 102.

[0058] During this process, both the connecting plates 110 and the adapters 112 are separated with the enclosure 102 (specifically, the fastening protrusions 158) and thus would not interfere with the enclosure 102, since the connecting plate 110 is separated from the enclosure 102 and the adapter 112 does not extend beyond the connecting plate 110 in the preparing position as shown in FIG. 3 A. This can avoid scratches on the connecting plate 110 and the enclosure 102, and make it easy to align the first fastening hole 154 with the second fastening hole 160.

[0059] Finally, the adapters 112 may be moved to the fastening position to be in contact with the fastening protrusions 158 of the enclosure 102, and then be fastened to the fastening protrusions 158 by the threaded fasteners 156. Since the adapters 112 are in contact with the fastening protrusions 158 of the enclosure 102 in their fastening positions, during the fastening process, the adapters 112 would not be displaced by the fastening force of the threaded fasteners 156, and thus the connection plates 110 engaged with the adapters 112 would not be forced to displace/deform. This can prevent the connecting plates 110 from pulling the metallic inserts 118 connected with the connecting plates 110 and exerting force on the metallic inserts 118, and thus can avoid mechanical damage to the insulator 108 during the fastening process.

[0060] The technical content and technical features of the present disclosure have been disclosed above. However, it is conceivable that, under the creative ideas of the present disclosure, those skilled in the art can make various changes and improvements to the concepts disclosed above, but these changes and improvements all belong to the protection scope of the present disclosure. The description of the above embodiments is exemplary rather than limiting, and the protection scope of the present disclosure is defined by the appended claims.

Claims

1. An insulator assembly (106) for a gas-insulated system (100) comprising: an insulator (108) comprising a central portion (114) extending along a central axis (A) and a leg (116) extending from the central portion (114) in a radial direction perpendicular to the central axis (A); a connecting plate (110) provided at an end (120) of the leg (116); and an adapter (112) movably mounted to the connecting plate (110) such that the adapter (112) is capable of moving relative to the connecting plate (110) from a preparing position to a fastening position in a direction away from the central portion (114), the adapter (112) comprising a fastening hole (154) for being fastened to an enclosure (102) of the gas-insulated system (100) by a threaded fastener (156) in the fastening position.

2. The insulator assembly (106) for a gas-insulated system (100) according to claim 1, wherein the adapter (112) comprises an adapter body (148) defining the fastening hole (154); the connecting plate (110) comprises a mounting hole (134) extending therethrough; and the adapter body (148) is provided in the mounting hole (134) and threadedly engaged with the mounting hole (134) to allow the adapter (112) to be moved between the preparing position and the fastening position.

3. The insulator assembly (106) for a gas-insulated system (100) according to claim 2, wherein the adapter body (148) comprises a contacting end (162) for contacting the enclosure (102) in the fastening position; the connecting plate (110) comprises a first side surface (144) facing the central portion (114) and a second side surface (146) opposite to the first side surface (144); and the contacting end (162) of the adapter (112) extends beyond the second side surface (146) when the adapter (112) is in the fastening position.

4. The insulator assembly (106) for a gas-insulated system (100) according to claim 2, wherein the adapter (112) further comprises a shielding cover (164) connected with the adapter body (148) at an end of the adapter body (148), and the shielding cover (164) extends around the adapter body (148) and comprises a curved surface (166).

5. The insulator assembly (106) for a gas-insulated system (100) according to claim 4, wherein the connecting plate (110) further comprises a connecting hole (136) for connecting a particle trapping member (138) of the gas-insulated system (100) to the connecting plate (110), and the shielding cover (164) covers the connection hole (136).

6. The insulator assembly (106) for a gas-insulated system (100) according to any one of claims 2-5, wherein the connecting plate (110) comprises a plate body (140) and a mounting boss (142) extending substantially perpendicular to the plate body (140), and the mounting boss (142) defines the mounting hole (134).

7. The insulator assembly (106) for a gas-insulated system (100) according to any one of claims 2-5, wherein the connecting plate (110) comprises a middle section (128) and a side section (130) adjoining the middle section (128); and the middle section (128) is connected with the end (120) of the leg (116), and the mounting hole (134) is provided at the side section (130).

8. The insulator assembly (106) for a gas-insulated system (100) according to claim 7, wherein the connecting plate (110) comprises two side sections (130) on opposite sides of the middle section (128), and each side section (130) is provided with a mounting hole (134).

9. The insulator assembly (106) for a gas-insulated system (100) according to any one of claims 1-5, wherein a metallic insert (118) is embedded in the end (120) of the leg (116), and the connecting plate (110) is connected with the metallic insert (118).

10. A gas-insulated system (100) comprising: an enclosure (102); and an insulator assembly (106) for a gas-insulated system (100) according to any one of claims 1 to 9, wherein the insulator assembly (106) is provided inside the enclosure (102); a connecting plate (110) of the insulator assembly (106) is separated from the enclosure (102); and an adapter (112) of the insulator assembly (106) is separated from the enclosure (102) in a preparing position, and is in contact with the enclosure (102) in a fastening position where the adapter (112) is fastened to the enclosure (102) by a threaded fastener (156).

11. The gas-insulated system (100) according to claim 10, wherein the enclosure (102) comprises a fastening protrusion (158), and the adapter (112) is fastened to the fastening protrusion (158) by the threaded fastener (156).

12. The gas-insulated system (100) according to claim 10 or 11, wherein the enclosure (102) has a cylindrical shape, and the connecting plate (110) extends substantially in a circumferential direction of the enclosure (102).

13. A method for assembling a gas-insulated system (100) comprising: providing an enclosure (102); and providing an insulator assembly (106) comprising: an insulator (108) comprising a central portion (114) extending along a central axis (A) and a leg (116) extending from the central portion (114) in a radial direction perpendicular to the central axis (A); a connecting plate (110) provided at an end (120) of the leg (116); and an adapter (112) movably mounted to the connecting plate (110) such that the adapter (112) is capable of moving relative to the connecting plate (110) from a preparing position to a fastening position in a direction away from the central portion (114), the adapter (112) comprising a first fastening hole (154) for being fastened to the enclosure (102) by a threaded fastener (156) in the fastening position.

14. The method for assembling a gas-insulated system (100) according to claim 13 further comprising: moving the adapter (112) to the preparing position; placing the insulator assembly (106) in position inside the enclosure (102); moving the adapter (112) to the fastening position; and connecting the adapter (112) to the enclosure (102) by the threaded fastener (156); wherein when the adapter (112) is moved to the fastening position, the connecting plate

(110) is separated from the enclosure (102), and the adapter (112) extends beyond the connecting plate (110) to be in contact with the enclosure (102).

15. The method for assembling a gas-insulated system (100) according to claim 14, wherein the enclosure (102) comprises a second fastening hole (160), and the method further comprises aligning the first fastening hole (154) with the second fastening hole (160) to place the insulator assembly (106) in position inside the enclosure (102).