Four-way bus for combined electric appliance and central conductor of four-way bus

Abstract

The utility model relates to a four-way bus for a composite apparatus and a central conductor thereof, the central conductor comprises a body, the body comprises four fixing surfaces used for connecting an external conductor and at least one assembling surface, the body is internally provided with a cavity, and the assembling surface is provided with an opening for communicating the cavity with an external space; and the at least one packaging unit is arranged on the assembling surface and used for shielding the opening, and the packaging unit is connected with the body through a first fastener. The packaging unit can seal the opening of the center conductor, is suitable for fixing the center conductor structure of the four-way joint in the cavity, and seals the fixed cavity, so that the center conductor for the four-way joint, which is a main loop module with a complicated structure, is in smooth transition as much as possible, and has no exposed shape mutation; therefore, the electric field distribution of the main loop of the four-way bus is more uniform, and the insulation reliability is higher.

Description

Technical Field

[0001] This application relates to the field of electrical technology, and particularly to a four-way busbar for gas-insulated switchgear and its central conductor. Background Art

[0002] Gas-insulated switchgear (GIS), fully known as "Gas Insulated Switchgear", refers to high-voltage switchgear that uses insulating gas (usually SF6 gas) as the main insulating medium. Compared with traditional air-insulated switchgear, it has the advantages of small volume, less floor area, high reliability, and convenient maintenance, and is widely used in high-voltage power systems. In order to save space and achieve a compact layout structure, four-way busbars are often used in GIS. A four-way busbar refers to a busbar that can be connected in four directions, allowing current to flow in from one direction and flow out through any one of the other three directions. This design is mainly used to achieve a compact layout and space saving in GIS equipment. Currently, most of the conductors of four-way busbars for GIS are formed by the intersection and welding of two equal-diameter cylinders, and the fasteners for fixing the contacts or connecting conductors in the four directions are mostly exposed. Due to the lack of sufficient shielding, these exposed fasteners connected to the main circuit cause the electric field at this part of the four-way busbar to be distorted, thereby leading to a decrease in the insulation margin. This shortcoming is not very obvious in low-voltage levels (below 126 kV). However, in high-voltage levels (above 363 kV), this problem will cause the discharge probability at the four-way busbar to relatively increase, thereby reducing the overall reliability of GIS. It may cause the busbar to burn out during live operation, resulting in serious power grid failures. Summary of the Invention

[0003] Based on this, it is necessary to provide a four-way busbar for gas-insulated switchgear and its central conductor with high safety for the above technical problems.

[0004] A central conductor of a four-way busbar, the central conductor comprising:

[0005] A body, including four fixing surfaces for connecting external conductors and at least one assembly surface, a cavity is provided inside the body, and an opening for communicating the cavity with the external space is provided on the assembly surface; and

[0006] At least one encapsulation unit, the encapsulation unit is provided on the assembly surface for shielding the opening, and the encapsulation unit is connected to the body through a first fastener.

[0007] The encapsulation unit can seal the opening of the central conductor, and is suitable for fixing the central conductor structure of the four-way joint inside the cavity, sealing the completed cavity, so that the external of the complex main circuit module of the central conductor for the four-way joint has a smooth transition as much as possible, without any exposed shape mutation, thereby making the electric field distribution of the main circuit of the four-way busbar more uniform and having higher insulation reliability.

[0008] In one embodiment, the encapsulation unit includes a pre-installed plate and an encapsulation shell. The pre-installed plate is used to be connected to the body through the first fastener to shield the opening, and the encapsulation shell is connected to the pre-installed plate and shields the first fastener.

[0009] In one embodiment, the assembly surface includes an installation part arranged around the opening. The first fastener is used to connect the edge of the pre-installed plate to the installation part, and the encapsulation shell can shield the installation part.

[0010] In one embodiment, at least one of the fixing surfaces is arc-shaped, the encapsulation shell is arc-shaped, and the arc-shaped encapsulation shell has a continuous radian with the fixing surface.

[0011] The arc of the encapsulation shell and the arc of the fixing surface can be joined into a complete shape. Even if there may be a gap between the encapsulation shell and the fixing surface, this makes the external form of the complex main circuit module of the four-way busbar have a smooth transition as much as possible.

[0012] In one embodiment, the pre-installed plate is recessed with a first fixing groove, and the first fastener passes through the first fixing groove to connect the pre-installed plate and the body.

[0013] The first fixing groove is used to accommodate the screw head to prevent the screw head from protruding. The embedded first fastener can also help save the space occupied by the encapsulation unit and improve the tightness between the pre-installed plate and the encapsulation shell.

[0014] In one embodiment, the encapsulation unit further includes a second fastener, and the second fastener connects the encapsulation shell and the pre-installed plate.

[0015] In one embodiment, a second fixing groove is provided in the middle of the encapsulation shell, and the second fastener passes through the second fixing groove and the pre-installed plate to connect the pre-installed plate and the encapsulation shell.

[0016] The second fixing groove is used to accommodate the screw head to prevent the screw head from protruding, and improve the safety of the pre-installed plate and the encapsulation shell.

[0017] In one embodiment, the second fixing groove has a groove bottom and a bottom surface arranged opposite to each other. The groove bottom is recessed on the outer surface of the encapsulation shell, and / or the bottom surface abuts against the pre-installed plate.

[0018] In one embodiment, the end of the second fastener does not exceed the surface of the encapsulation shell.

[0019] A four-way busbar for a combined electrical apparatus includes the central conductor of the four-way busbar described above. Description of the Drawings

[0020] Figure 1 It is a partial structural schematic diagram of a four-way busbar according to an embodiment of the present application.

[0021] Figure 2 It is a partial structural cross-sectional view of a central conductor according to an embodiment of the present application. Detailed Embodiments

[0022] To make the above objects, features, and advantages of the present application more obvious and understandable, the following detailed description of the specific embodiments of the present application will be given in conjunction with the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0023] In the description of the present application, it should be understood that if there are terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or positional relationship indicated by these terms is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present application.

[0024] In addition, if there are terms such as "first" and "second", these terms are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present application, if there is a term "plurality", the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0025] In this application, unless otherwise clearly stipulated and defined, if terms such as "installed", "connected", "linked", "fixed", etc. appear, these terms shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] In this application, unless otherwise clearly stipulated and defined, if there is a description such as a first feature being "on" or "under" a second feature, its meaning can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on the top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher horizontal level than the second feature. The first feature being "under", "beneath" and "under the bottom of" the second feature can be that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower horizontal level than the second feature.

[0027] It should be noted that if an element is referred to as being "fixed to" or "arranged on" another element, it can be directly on the other element or there can also be an intermediate element. If an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. If so, the terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used in this application are only for the purpose of illustration and do not represent the only implementation.

[0028] Refer to Figure 1 , Figure 1 shows a schematic structural diagram of a four-way busbar 1 in an embodiment of the present application, Figure 2 shows a central conductor 10 provided in an embodiment of the present application, for Figure 1 the four-way busbar 1 shown.

[0029] The central conductor 10 includes a body 200 and at least one encapsulation unit 100. The body 200 includes four fixing surfaces 210 for connecting external conductors 20 and at least one assembly surface 220. A cavity 201 is provided inside the body 200, and an opening 202 for communicating the cavity 201 with the external space is provided on the assembly surface 220. The encapsulation unit 100 is arranged on the assembly surface 220 for shielding the opening 202, and the encapsulation unit 100 is connected to the body 200 through a first fastener 111.

[0030] The encapsulation unit 100 is capable of closing the opening 202 of the central conductor 10, and is suitable for fixing the central conductor 10 structure of the four-way joint inside the cavity 201, closing the completed fixed cavity 201, making the external of the complex main circuit module of the central conductor 10 for the four-way joint as smooth as possible, without any exposed shape mutations, so that the electric field distribution of the main circuit of the four-way busbar 1 is more uniform and has higher insulation reliability. It is especially applicable to products that require a higher insulation safety margin, such as high-voltage level usage scenarios and GIS using environmentally friendly insulating gases.

[0031] The body 200 is a polyhedron with a cavity 201. The cavity 201 is used to extend and operate and install the external conductor 20 on the fixing surface 210. The body 200 can be, for example Figure 2 The shown regular tetrahedron, which has four fixing surfaces 210 for connecting the external conductor 20, and the other two are assembly surfaces 220.

[0032] In one embodiment, the encapsulation unit 100 includes a pre-installation plate 110 and an encapsulation shell 120. The pre-installation plate 110 is used to connect to the body 200 through the first fastener 111 to cover the opening 202, and the encapsulation shell 120 is connected to the pre-installation plate 110 and covers the first fastener 111.

[0033] The encapsulation shell 120 is used to form a relatively smooth outer shape, form a part of the outer surface of the central conductor 10, and realize covering the opening 202 and other structures. The pre-installation plate 110 is mainly used to cover the opening 202 and for installing the encapsulation shell 120. The pre-installation plate 110 is arranged between the encapsulation shell 120 and the assembly surface 220. At least part of one side of the pre-installation plate 110 abuts against the assembly surface 220, and at least part of the other side abuts against the encapsulation shell 120.

[0034] The pre-installation plate 110 is provided with a through fastening hole. The first fastener 111 passes through the fastening hole and is installed on the body 200. The first fastener 111 is arranged at the edge of the pre-installation plate 110. Specifically, the first fastener 111 is a screw. After the screw is connected, there is a protruding screw head left on one side of the pre-installation plate 110, which is easy to have electrical contact with the outside. The encapsulation shell 120 can cover the screw to avoid safety problems.

[0035] In one embodiment, the assembly surface 220 includes an installation portion 221 arranged around the opening 202. The first fastener 111 is used to connect the edge of the pre-installation plate 110 to the installation portion 221, and the encapsulation shell 120 can cover the installation portion 221.

[0036] Specifically, the installation part 221 forms a stepped surface that sinks towards the cavity 201. The pre-installed plate 110 is placed against the stepped surface. The edges of the stepped surface enclose an opening 202 of the cavity 201. The pre-installed plate 110 abuts against the stepped surface to shield the opening 202. There may be a gap between the outer edge of the pre-installed plate 110 and the bent part of the stepped surface.

[0037] In one embodiment, at least one of the fixing surfaces 210 is arc-shaped, and the encapsulation shell 120 is arc-shaped. The arc-shaped encapsulation shell 120 has a continuous radian with the fixing surface 210.

[0038] Specifically, after the fixing surface 210 is connected to the external conductor 20, the whole combined with the external conductor 20 has a certain radian. The radian of the encapsulation shell 120 is continuous with the radian of the fixing surface 210, which means that the arc of the encapsulation shell 120 and the arc of the fixing surface 210 can be connected to form a complete shape. Even if there may be a gap between the encapsulation shell 120 and the fixing surface 210, this makes the external form of the complex main circuit module of the four-way busbar 1 have a smooth transition as much as possible.

[0039] The outer periphery of the encapsulation shell 120 has a cut surface. The cut surface is formed in the thickness direction of the encapsulation shell 120. The cut surface is horizontally arranged, parallel to the assembly surface 220 and abuts against the assembly surface 220. The inner periphery of the cut surface is flush with the outer periphery of the installation part 221. Starting from the inner periphery of the cut surface and moving inwards, above the sunken installation part 221, a space is formed to accommodate the end of the pre-installed plate 110 and the first fastener 111. The outer edge of the side of the pre-installed plate 110 facing the encapsulation shell 120 is chamfered to match the radian of the encapsulation shell 120.

[0040] In one embodiment, the pre-installed plate 110 is recessed with a first fixing groove 112, and the first fastener passes through the first fixing groove 112 to connect the pre-installed plate 110 and the body 200.

[0041] Specifically, the first fixing groove 112 is recessed on the surface of the pre-installed plate 110 close to the encapsulation shell 120, and the first fixing groove 112 communicates with a through fastening hole. As described above, the first fastener 111 is a screw. After the screw is connected, there is a protruding screw head remaining on one side of the pre-installed plate 110, which is likely to have electrical contact with the outside. The first fixing groove 112 is used to accommodate the screw head to prevent the screw head from protruding. The embedded first fastener 111 can also help save the space occupied by the encapsulation unit 100 and improve the tightness between the pre-installed plate 110 and the encapsulation shell 120.

[0042] In one embodiment, the encapsulation unit 100 further includes a second fastener 121, and the second fastener 121 connects the encapsulation shell 120 and the pre-installed plate 110.

[0043] Specifically, the pre-mounted plate 110 is provided with through fastening holes. The second fastener 121 is passed through the fastening holes and finally installed on the pre-mounted plate 110. The second fastener 121 is disposed in the middle of the pre-mounted plate 110 and the encapsulation shell 120. Specifically, the second fastener 121 is a screw.

[0044] In one embodiment, a second fixing groove 122 is provided in the middle of the encapsulation shell 120. The second fastener 121 is passed through the fixing groove and the pre-mounted plate 110 to connect the pre-mounted plate 110 and the encapsulation shell 120.

[0045] Specifically, the second fixing groove 122 is recessed in the surface of the pre-mounted plate 110 close to the encapsulation shell 120. The pre-mounted plate 110 is also provided with fastening holes in the middle. The second fixing groove 122 communicates with the through fastening holes. The second fastener 121 sequentially passes through the second fixing groove 122 and the fastening holes to complete the connection between the pre-mounted plate 110 and the encapsulation shell 120.

[0046] As described above, the second fastener 121 is a screw, and the depth of the second fixing groove 122 is greater than the height of the screw head. After the screw connection, there is a protruding screw head remaining on one side of the pre-mounted plate 110, which is likely to cause electrical contact with the outside. The second fixing groove 122 is used to accommodate the screw head to prevent the screw head from protruding, and there is still some surplus space after accommodating the screw head.

[0047] In one embodiment, the second fixing groove 122 has a groove bottom 123 and a bottom surface 124 arranged opposite to each other. The groove bottom 123 is recessed in the outer surface of the encapsulation shell 120, and / or the bottom surface 124 abuts against the pre-mounted plate 110. Specifically, the groove bottom 123 is used to abut against the second fastener 121, and the bottom surface 124 is used to abut against the pre-mounted plate 110. The second fixing groove 122 can be formed by partially recessing in the middle, or can be formed by partially removing the encapsulation plate. Preferably, as Figure 2 shown, the second fixing groove 122 is formed by partially recessing in the middle, and there is a gap between the other part of the encapsulation shell 120 and the pre-mounted plate 110.

[0048] In one embodiment, the end of the second fastener 121 does not exceed the surface of the encapsulation shell 120.

[0049] A four-way busbar 1 for a combined electrical apparatus includes the central conductor 10 of the four-way busbar 1 as described above.

[0050] The four-way busbar 1 uses a spherical center conductor 10 as the center connection of the four-way connection. Fasteners are used to connect the contacts or conductors of the four branches. The inside of the center conductor 10 is a hollow structure, and all fasteners in all directions can be placed inside the center spherical conductor. Finally, the assembly of the non-busbar end face (assembly face 220) of the center spherical conductor is completed by the shielding of the encapsulation unit 100 introduced in this application. The spherical conductor structure can effectively uniform the electric field around the conductor under a reasonable electric field design structure, thereby improving the overall insulation safety margin of the four-way busbar 1 and enhancing the reliability of the GIS product.

[0051] Preferably, the four-way busbar 1 can be processed and formed by a casting process for the conductor and the busbar housing. Without increasing the processing difficulty, the shapes of the center conductor 10 and the outer shell are more conducive to uniforming the electric field around the main circuit than the existing structure.

[0052] To achieve the above design purpose, the four-way busbar 1 adopts a structure with openings on the side of the center conductor 10. During busbar assembly, the operator can easily access the connection fasteners inside the conductor through this opening. These fasteners are responsible for fixing the contacts or conductors in the four directions on the center conductor 10 to meet the connection requirements of the main circuit of the equipment. After assembly, the encapsulation unit 100 is fixed on one side of the conductor opening, making the center conductor 10 form an approximately completely smooth spherical surface, making the surrounding electric field distribution more uniform, thereby improving the insulation performance of the busbar.

[0053] Preferably, in practice, both the four-way center conductor 10 and the housing of the four-way busbar 1 can be made of cast aluminum alloy to simplify the process of processing and forming the conductor; they can also be machined from solid bars to obtain the corresponding parts. In some cases where large currents need to pass through, the center conductor 10 may be processed using copper or copper alloy.

[0054] Preferably, the surface of the center conductor 10 is polished because the smoother the surface of the conductor, the better its insulation performance. It is also possible to spray paint or spray plastic on the surface of the center conductor 10 to further improve the insulation reliability.

[0055] The beneficial effects of the four-way busbar for combined electrical appliances and its center conductor in this application are:

[0056] Almost all connection fasteners can be shielded inside the center conductor 10, making the center conductor 10 a spherical structure. The electric field distribution of this structure is more uniform, so its insulation performance is better than that of the existing center conductor 10 with two intersecting cylinders. Fundamentally, the insulation safety margin of the product is improved, and it has a wide application prospect especially in high-voltage GIS.

[0057] Adopting a structure with side openings does not affect the installation and connection of the main circuit contacts or conductors in all four axial directions. Due to the hollow structure of the central conductor 10, all connection fasteners are shielded inside the conductor. After complete installation, the central conductor 10 has a spherical-like structure, with a more uniform electric field distribution and no exposed fasteners with sudden shape changes, greatly improving the insulation performance of the four-way busbar 1 and effectively reducing the probability of discharge faults.

[0058] In the conventional structure, four main circuit conductors are located in the XY axial directions, and the openings 202 and shielding are in the Z-axis direction. Although the present utility model has the ability to arrange the main circuit conductors in the Z-axis direction, this connection method is not recommended considering the product reliability.

[0059] By reasonably setting the fixed connection positions and the distribution of sliding connections, the effective fixation of the central conductor 10 is achieved. Usually, one of the four directions on the XY axes is a fixed connection, and the other three are pluggable sliding connections.

[0060] It is applicable to various contact forms, with a wide range of adaptability, and has good application prospects especially in products with high voltage levels.

[0061] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0062] The above-described embodiments only represent several implementation manners of the present application. Their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A central conductor of a four-way busbar, characterized in that, The central conductor includes: a body including four fixing surfaces for connecting to external conductors and at least one fitting surface, a cavity being provided in the body, and an opening being provided in the fitting surface to communicate the cavity with the external space; and at least one encapsulation unit provided on the fitting surface for shielding the opening, and the encapsulation unit is connected to the body by a first fastener.

2. The center conductor of the four-way busbar according to claim 1, characterized in that, The encapsulation unit includes a pre-installed plate and an encapsulation shell. The pre-installed plate is used to be connected to the body by the first fastener to shield the opening, and the encapsulation shell is connected to the pre-installed plate and shields the first fastener.

3. The central conductor of the four-way busbar according to claim 2, characterized in that, The fitting surface includes an installation portion disposed around the opening. The first fastener is used to connect the edge of the pre-installed plate to the installation portion, and the encapsulation shell can shield the installation portion.

4. The center conductor of the four-way bus bar according to claim 2, characterized in that At least one of the fixing surfaces is arc-shaped, and the encapsulation shell is arc-shaped, and the arc-shaped encapsulation shell has a continuous curvature with the fixing surface.

5. The center conductor of the four-way busbar according to claim 2, characterized in that, The pre-installed plate is recessed with a first fixing groove, and the first fastener passes through the first fixing groove to connect the pre-installed plate and the body.

6. The center conductor of the four-way busbar according to claim 2, characterized in that The encapsulation unit further includes a second fastener, and the second fastener connects the encapsulation shell and the pre-installed plate.

7. The central conductor of the four-way busbar according to claim 6, characterized in that, A second fixing groove is provided in the middle of the encapsulation shell, and the second fastener passes through the second fixing groove and the pre-installed plate to connect the pre-installed plate and the encapsulation shell.

8. The central conductor of the four-way busbar according to claim 7, characterized in that, The second fixing groove has a groove bottom and a bottom surface which are arranged in opposite directions. The groove bottom is recessed on the outer surface of the encapsulation shell, and / or the bottom surface abuts against the pre-installed plate.

9. The center conductor of the four-way busbar according to claim 6, wherein, 10. A four-way busbar for a combined electrical apparatus, characterized in that, The end of the second fastener does not exceed the surface of the encapsulation shell. The central conductor of the four-way busbar according to any one of claims 1-9.

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