Voltage-sharing insulator for environment-friendly gas insulation cabinet

Abstract

The invention discloses a voltage-sharing insulator for an environment-friendly gas insulation cabinet, which comprises an insulation layer, a first insert and a second insert, the first insert is arranged at the first end of the insulation layer, the second insert is arranged at the second end of the insulation layer, and the axis of the first insert and the axis of the second insert coincide with the axis of the insulation layer. Each of the first insert and the second insert comprises a spherical end and a connecting end, the spherical ends of the first insert and the second insert are completely embedded into the insulating layer, and the connecting ends extend out of the insulating layer. The composite insulator is excellent in insulation performance, and has transmission, voltage-sharing and shielding functions besides the basic functions of a traditional insulator.

Description

Technical Field

[0001] This invention relates to the field of switchgear insulators, and in particular to an equalizing insulator for environmentally friendly gas-insulated switchgear. Background Technology

[0002] An insulator is a layer of electrical insulation installed between conductors at different potentials in a switchgear. Insulators used in switchgear are mostly epoxy resin cast composite insulators. Insulators, located at different positions within the switchgear, serve to withstand voltage and mechanical stress. At different voltage levels, the height of the insulator and the skirt on its outer surface are increased to meet the insulation levels required for the corresponding voltage levels as specified in GB / T 3906 and GB / T 11022.

[0003] Currently, SF6 gas-insulated switchgear (GIS) primarily uses epoxy resin-cast basin insulators, three-post insulators, and single-post insulators. Replacing traditional SF6 gas with dry air as the environmentally friendly insulating gas in GIS represents the mainstream development direction for future medium- and high-voltage switchgear. While traditional basin insulators offer advantages in insulation, support, and gas chamber isolation within SF6 gas switchgear, their application in dry-air environmentally friendly gas switchgear presents challenges such as high cost, poor structural compatibility, significant impact on insulation reliability due to the substitute gas, potential for localized electric field exceedances, and increased insulation risks. Therefore, they cannot be directly used in dry-air gas-insulated switchgear. Summary of the Invention

[0004] This invention addresses the technical problems existing in the prior art by providing an equalizing insulator for environmentally friendly gas-insulated cabinets. It has excellent insulation performance and, in addition to meeting the basic functions of traditional insulators, also has transmission, equalizing and shielding functions.

[0005] The technical solution adopted by the present invention to solve its technical problem is: an equalizing insulator for an environmentally friendly gas-insulated cabinet, comprising an insulating layer, a first insert and a second insert, wherein the first insert is disposed at a first end of the insulating layer, the second insert is disposed at a second end of the insulating layer, and the axes of the first insert and the second insert coincide with the axis of the insulating layer; the first insert and the second insert respectively include a spherical end and a connecting end, wherein the spherical end of both is completely embedded in the insulating layer, and the connecting end extends to the outside of the insulating layer.

[0006] Furthermore, the insulating layer has a spindle-shaped structure, and its cross-sectional diameter gradually decreases from the middle to both ends along the axial direction.

[0007] Furthermore, the end face of the first end of the insulating layer is parallel to the end face of the second end; the outer surface of the insulating layer is a continuous smooth arc-shaped surface.

[0008] Furthermore, the minimum cross-sectional diameter of the first end of the insulating layer is greater than the minimum cross-sectional diameter of the second end of the insulating layer; the diameter of the spherical end of the first insert is greater than the diameter of the spherical end of the second insert.

[0009] Furthermore, the connecting ends of the first insert and the second insert are respectively cylindrical.

[0010] Furthermore, it also includes a third insert and a fourth insert, wherein the third insert is fixedly connected to the connection end of the first insert, and the fourth insert is fixedly connected to the connection end of the second insert.

[0011] Furthermore, the third and fourth inserts are rotatably connected to a transmission component via a bearing structure, and the end of the transmission component away from the insulating layer is provided with a gear.

[0012] Furthermore, the insulating layer is formed by epoxy resin casting.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The first and second inserts of the present invention are provided with spherical ends, and the spherical ends are completely embedded in the insulating layer, that is, spherical electrodes are used, thereby forming a spherical gap electric field, which is a slightly non-uniform electric field. This increases the radius of curvature of the electrode, improves the edge of the electrode, makes the electric field distribution within the insulating layer uniform, and improves the breakdown field strength of the gap. Furthermore, the spherical ends can reduce the maximum field strength inside the insulating layer, slow down the aging rate of the insulating material, and improve the reliability of the insulating layer. At the same time, the maximum diameter of the spherical ends of the first and second inserts can naturally shield the three-interface region of the insulating layer, avoiding the technical problems of surface flashover and partial discharge caused by the easy accumulation of charge and the presence of interface polarization effect in this region.

[0015] 2. The insulating layer of the present invention has a spindle structure, the shape of which is similar to the field strength contour distribution of an ideal spherical gap electric field, so that the electrode and the insulating layer form an excellent insulating fit, and the electric field on the surface of the insulating layer is uniformly distributed, avoiding excessive local electric field and reducing the risk of creepage and surface flashover.

[0016] 3. The third and fourth inserts are rotatably connected to a transmission component via bearings. The end of the transmission component away from the insulation layer is provided with a gear, which enables the equalizing insulator to have a transmission function. This transmission method replaces the traditional transmission method of the insulating screw, avoiding the discharge and creepage phenomena that occur when the traditional insulating screw is used in the tank-type environmentally friendly gas insulation cabinet.

[0017] 4. Fixing multiple equalizing insulators at a certain installation angle (based on the electrode shape) at the required equalizing shielding location can reduce the non-uniformity of the electric field, prevent breakdown or discharge caused by excessive local electric field strength, and achieve the equalizing shielding function. No other equipment needs to be installed, thus avoiding increased costs.

[0018] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments; however, the voltage equalizing insulator for environmentally friendly gas-insulated cabinets of the present invention is not limited to the embodiments. Attached Figure Description

[0019] Figure 1 This is a front view (internal perspective of the insulating layer) of Embodiment 1 of the present invention.

[0020] Figure 2 This is a schematic diagram of the voltage equalization and shielding function of Embodiment 1 of the present invention;

[0021] Figure 3 This is a three-dimensional structural schematic diagram of Embodiment 2 of the present invention;

[0022] In the figure: 1. Insulating layer; 2. First insert; 21. First spherical end; 22. First connecting end; 3. Second insert; 31. Second spherical end; 32. Second connecting end; 4. Third insert; 5. Fourth insert; 6. Bearing structure; 7. Transmission component; 71. Gear; 8. High potential conductor; 81. Protrusion; 9. Low potential conductor. Detailed Implementation

[0023] In this invention, the terms "first," "second," etc., are used only to distinguish similar objects, not to describe a specific order or sequence, nor should they be construed as indicating or implying relative importance. The use of terms such as "upper," "lower," "left," "right," "front," "rear," "inner," "outer," and "top / bottom" to indicate orientation or positional relationships is based on the orientation or positional relationships shown in the accompanying drawings, and is only for the convenience of describing the invention, not to indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the scope of protection of this invention. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0024] Furthermore, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] Example 1

[0026] Please see Figure 1 As shown, an equalizing insulator for an environmentally friendly gas-insulated cabinet according to the present invention includes an insulating layer 1, a first insert 2, and a second insert 3. The first insert 2 is disposed at a first end of the insulating layer 1, and the second insert 3 is disposed at a second end of the insulating layer 1. The axes of the first insert 2 and the second insert 3 coincide with the axis of the insulating layer 1. The first insert 2 and the second insert 3 each include a spherical end and a connecting end, and the spherical ends of both are completely embedded in the insulating layer 1, while the connecting ends extend outside the insulating layer 1. Specifically, the connecting ends of the first insert 2 and the second insert 3 are respectively cylindrical, and the transition area between the spherical ends and the connecting ends has a smooth transition arc surface. The insulating layer 1 is cast from epoxy resin. For ease of distinction, the spherical end of the first insert 2 is named the first spherical end 21, and the connecting end is named the first connecting end 22; the spherical end of the second insert 3 is named the second spherical end 31, and the connecting end is named the second connecting end 32.

[0027] Because the first insert 2 and the second insert 3 are provided with spherical ends, and the spherical ends are completely embedded in the insulating layer 1, i.e., spherical electrodes are used, a spherical gap electric field can be formed. This is a slightly non-uniform electric field, which increases the radius of curvature of the electrode, improves the edge of the electrode, makes the electric field distribution in the insulating layer 1 uniform, and improves the breakdown field strength of the gap. In addition, the spherical ends can reduce the maximum field strength inside the insulating layer 1, slow down the aging rate of the insulating material, and improve the reliability of the insulating layer 1. At the same time, the maximum diameter of the spherical ends of the first insert 2 and the second insert 3 can naturally shield the three-interface region of the insulating layer 1, avoiding the technical problems of surface flashover and partial discharge caused by the easy accumulation of charge and the presence of interface polarization effect in this region.

[0028] The insulating layer 1 has a spindle-shaped structure, with its cross-sectional diameter gradually decreasing from the middle to both ends along the axial direction. The end faces of the first and second ends of the insulating layer 1 are parallel to each other, and the outer surface of the insulating layer 1 is a continuous, smooth arc-shaped surface. Specifically, the spindle structure is a geometric body formed by rotating a smooth arc curve around the axis of the insulating layer 1. The spindle structure makes the shape of the insulating layer 1 approximate the isopleths of the electric field strength in an ideal spherical gap, resulting in excellent insulation between the electrode and the insulating layer 1. This ensures a uniform electric field distribution on the surface of the insulating layer 1. Calculations using finite element simulation software show that the surface electric field strength of the insulating layer 1 is less than 2.2 kV / mm, which avoids excessively strong local electric fields and reduces the risk of creepage and surface flashover.

[0029] The minimum cross-sectional diameter of the first end of the insulating layer 1 is greater than the minimum cross-sectional diameter of the second end of the insulating layer 1. Similarly, the diameter of the first spherical end 21 of the first insert 2 is greater than the diameter of the second spherical end 31 of the second insert 3, and the diameter of the first connecting end 22 of the first insert 2 is also greater than the diameter of the second connecting end 32 of the second insert 3. That is, the first insert 2 is the high-potential end, and the second insert 3 is the low-potential end. Specifically, the distance between the first spherical end 21 and the second spherical end 31, the curvature of the outer surface of the insulating layer 1, and the dimensions of the insulating layer 1, the first spherical end 21, and the second spherical end 31 can be adjusted according to requirements.

[0030] The present invention also includes a third insert 4 and a fourth insert 5. The third insert 4 is fixedly connected to the first connecting end 22 of the first insert 2, and the fourth insert 5 is fixedly connected to the second connecting end 32 of the second insert 3, so as to connect with other components through the third insert 4 and the fourth insert 5. Specifically, the structure of the third insert 4 and the fourth insert 5 can be adjusted according to the installation position and the required function.

[0031] When voltage-equalizing insulators are required for voltage-equalizing shielding, multiple voltage-equalizing insulators are fixed at a specific installation angle (based on the electrode shape) at the desired voltage-equalizing shielding location to achieve the voltage-equalizing shielding function. No additional equipment is required, thus avoiding increased costs. Specifically, as follows... Figure 2 As shown, the high-potential conductor 8 and the low-potential conductor 9 are coaxially arranged, and their electric field distribution is a slightly non-uniform electric field. When there is any protrusion 81 on the high-potential conductor 8, it no longer satisfies the slightly non-uniform electric field distribution. Insulators are installed on both sides of the protrusion 81 for voltage equalization shielding. Even if the first insert 2 of the two voltage equalization insulators is connected to the high-potential conductor 8 through the third insert 4, and the second insert 3 is connected to the low-potential conductor 9 through the fourth insert 5, the two first inserts 2 make it possible for... Figure 2The area enclosed by the dashed line is at the same potential, achieving voltage equalization and shielding, which utilizes the principle of electrostatic shielding. In real-world applications, such as compact tank-type environmentally friendly gas-insulated switchgear, the main busbar often adopts a tubular structure, forming an electric field between coaxial cylindrical electrodes with the gas tank. When conductors of different shapes need to be installed on the main busbar (such as the static contacts of grounding switches), a highly non-uniform electric field will be formed. Traditional insulators do not have the functions of voltage equalization and shielding insulation, so other primary equipment needs to be installed, leading to increased costs. However, by using the voltage equalization insulator of this invention for support and isolation, it can simultaneously have the functions of voltage equalization and shielding, eliminating the need to install other primary equipment and avoiding increased costs.

[0032] The present invention provides an equalizing insulator for environmentally friendly gas-insulated cabinets, which has reliable electrical performance and meets the insulation level requirements of GB / T 3906 and GB / T 11022.

[0033] Implementation of Column 2

[0034] Please see Figure 3 As shown, the equalizing insulator for an environmentally friendly gas-insulated cabinet according to the present invention differs from that in Embodiment 1 in that the third insert 4 and the fourth insert 5 are rotatably connected to a transmission member 7 via a bearing structure 6. A gear 71 is provided at the end of the transmission member 7 away from the insulating layer 1, enabling the insulator to have a transmission function. The gear 71 on the transmission member 7 is used to mesh with gears of other components in the environmentally friendly gas-insulated cabinet to achieve the transmission function.

[0035] Because tank-type environmentally friendly gas-insulated cabinets have a compact structure, the main busbar often adopts a tubular structure, forming an electric field between coaxial cylindrical electrodes with the gas box. However, when there is an insulating rod with transmission function between the two electrodes, surface discharge is prone to occur, increasing the insulation risk. The transmission method of the equalizing insulator of this invention replaces the traditional transmission method of the insulating rod, which can avoid the discharge and creepage phenomena that occur when the traditional insulating rod is used in tank-type environmentally friendly gas-insulated cabinets.

[0036] The present invention provides an equalizing insulator for an environmentally friendly gas-insulated cabinet. The parts not described herein are the same as or can be implemented using existing technologies.

[0037] The above embodiments are only used to further illustrate an equalizing insulator for an environmentally friendly gas-insulated cabinet according to the present invention. However, the present invention is not limited to the embodiments. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A grading ring for an environmentally friendly gas insulated switchgear, comprising an insulating layer, a first insert and a second insert, the first insert being arranged at a first end of the insulating layer, the second insert being arranged at a second end of the insulating layer, and the axis of the first and second inserts coinciding with the axis of the insulating layer; characterized in that: The first and second inserts respectively comprise a spherical end and a connecting end, and the spherical ends of the two are completely embedded in the insulation layer, and the connecting ends extend out of the insulation layer.

2. The grading ring for an environmentally friendly gas insulated switchgear according to claim 1, characterized in that: The insulation layer has a spindle structure, and the cross-sectional diameter gradually decreases from the middle to the two ends along the axial direction.

3. The grading ring for an environmentally friendly gas insulated switchgear according to claim 2, characterized in that: The end surface of the first end of the insulation layer is parallel to the end surface of the second end; and the outer surface of the insulation layer is a continuous smooth arc surface.

4. The grading ring for an environmentally friendly gas insulated switchgear according to claim 2, characterized in that: The minimum cross-sectional diameter of the first end of the insulation layer is greater than the minimum cross-sectional diameter of the second end of the insulation layer; and the diameter of the spherical end of the first insert is greater than the diameter of the spherical end of the second insert.

5. The grading ring for an environmentally friendly gas insulated switchgear according to claim 1, characterized in that: The connecting ends of the first and second inserts are respectively in a cylindrical shape.

6. The grading ring for an environmentally friendly gas insulated switchgear according to claim 1 or 5, characterized in that: The third and fourth inserts are further included, the third insert is fixedly connected with the connecting end of the first insert, and the fourth insert is fixedly connected with the connecting end of the second insert.

7. The grading ring for an environmentally friendly gas insulated switchgear according to claim 6, characterized in that: The third and fourth inserts are respectively rotatably connected with transmission members through bearing structures, and the transmission members are provided with gears at one ends away from the insulation layer.

8. The grading ring for an environmentally friendly gas insulated switchgear according to claim 1, characterized in that: The insulation layer is formed by pouring epoxy resin.

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