Bushing end voltage-sharing device for AC voltage-withstanding test

Abstract

The utility model relates to a bushing end voltage-sharing device for an AC voltage-withstanding test. The voltage-sharing device comprises a voltage-sharing cover, a voltage-sharing ring, a fixed support and a telescopic adjusting rod. The voltage-sharing cover is driven to move up and down by adjusting the length of the telescopic adjusting rod, so that the voltage-sharing cover covers the wiring copper bar at the end part of the sleeve, the inner wall of the voltage-sharing cover is in contact with the wiring copper bar to form electric connection, the wiring copper bar is prevented from protruding to form a tip, and the voltage-sharing cover is relatively convenient to mount and dismount; an overhead working truck or a scaffold does not need to be built, manpower and material resources are saved, the test efficiency is improved, and risks of equipment and personnel in the installation process are reduced; besides, the voltage-sharing cover is also connected with a voltage-sharing ring through a fixing support, the voltage-sharing ring can enlarge an equipotential area and play a role in suppressing point discharge, and under the combined action of the voltage-sharing ring and the voltage-sharing cover, corona discharge and point discharge at the end part of the sleeve during the AC voltage-withstanding test can be effectively suppressed, and corona loss and measurement interference are reduced.

Description

Technical Field

[0001] This application relates to the technical field of withstand voltage testing of electrical equipment, and particularly to a grading device for the end of a bushing for AC withstand voltage testing. Background Art

[0002] After a sulfur hexafluoride gas-insulated metal-enclosed switchgear (hereinafter referred to as GIS) arrives at the site and is installed and commissioned, or after major repairs and replacement of internal components, an AC withstand voltage test is required. Only when the AC withstand voltage test result is qualified can the equipment be put into operation. In related technologies, a variable-frequency series resonance test device is generally used for the 220 kV GIS AC withstand voltage test. By compensating reactors and adjusting the test frequency, the test circuit is brought to a resonant state to generate high voltage. During on-site tests, the high-voltage output end of the variable-frequency series resonance test device is connected to the copper bar at the end of the GIS outgoing bushing through test leads. For some GIS without outgoing bushings, a temporary test tooling bushing needs to be installed for testing.

[0003] According to the requirements of the "DL / T 618-2022 Code for On-Site Handover Tests of Gas-Insulated Metal-Enclosed Switchgear", the on-site AC withstand voltage value of 220 kV GIS is 100% of the factory test voltage, that is, 460 kV. High voltage will generate strong corona and tip discharge at the high-voltage output end of the variable-frequency series resonance test device, the test leads connected to the GIS, and the copper bar at the end of the GIS outgoing bushing or the temporary test tooling bushing, causing corona loss and flashover risk, and affecting the normal conduct of the test. Therefore, grading measures need to be taken at the above positions to reduce the impact of corona and tip discharge on the test. Generally, the high-voltage output end of the variable-frequency series resonance test device is designed with grading measures, and test leads can also use non-corona leads, while a grading ring or grading cap needs to be specially installed on the copper bar at the end of the GIS outgoing bushing or the temporary test tooling bushing.

[0004] The corona shielding measures for the copper bar at the end of the GIS outgoing bushing or the temporary test tooling bushing in related technologies generally adopt the installation of a grading ring or grading cap. The grading ring or grading cap is made of metal materials such as aluminum or stainless steel, with a heavy weight and a large volume; some grading rings or grading caps for temporary tests are made of non-metallic materials. Due to different voltage levels and usage scenarios, the design dimensions and shapes of the grading ring and grading cap also vary. Installation or disassembly requires the cooperation of an aerial work vehicle or the erection of a scaffold, which will result in a waste of manpower and material resources and reduce the test efficiency. In addition, at some construction sites, such as indoor GIS or high-rise designed GIS, the conditions for using an aerial work vehicle are not available, so there is a situation where the grading cap or grading ring cannot be installed, or a temporary scaffold needs to be erected, wasting more manpower and material resources and having a low test efficiency. In addition, when installing a grading ring with a large volume and a heavy weight, there is a risk of damaging the bushing porcelain sleeve, and there is also a risk of falling from a height for the installation personnel. Summary of the Invention

[0005] Based on this, it is necessary to overcome the defects of the prior art and provide a grading device for the end of the bushing used in the AC withstand voltage test, which can improve the test efficiency, improve safety, and reduce labor costs.

[0006] A grading device for the end of the bushing used in the AC withstand voltage test, the grading device for the end of the bushing used in the AC withstand voltage test includes:

[0007] A grading cover for covering the connection copper bar at the end of the bushing;

[0008] A grading ring circumferentially arranged around the grading cover in the peripheral area of the grading cover;

[0009] A fixing bracket, the grading ring is connected to the grading cover through the fixing bracket; and

[0010] A telescopic adjusting rod connected to at least one of the grading cover, the grading ring and the fixing bracket.

[0011] In one embodiment, the grading device for the end of the bushing used in the AC withstand voltage test further includes a support arm and a locking member, the support arm is connected between the telescopic adjusting rod and at least one of the grading cover, the grading ring and the fixing bracket; one end of the support arm is rotatably connected to the top end of the telescopic adjusting rod, when the support arm rotates relative to the telescopic adjusting rod to a preset angle, one end of the support arm is connected and fixed to the top end of the telescopic adjusting end through the locking member; the other end of the support arm is connected and fixed to at least one of the grading cover, the grading ring and the fixing bracket.

[0012] In one embodiment, the telescopic adjusting rod includes a plurality of insulating rods connected in sequence and capable of telescopic adjustment and a connection head connected to the insulating rod at the top position, and the connection head is rotatably connected to the end of the support arm.

[0013] In one embodiment, the grading ring is provided as an airbag, and a conductive layer is provided on the outer surface of the airbag.

[0014] In one embodiment, the grading ring is an airbag made of an elastic material with a thickness of 1 mm to 5 mm.

[0015] In one embodiment, the airbag is an inflatable airbag, and an air replenishing joint is provided on the airbag.

[0016] In one embodiment, the fixing brackets are provided in plurality and arranged at intervals in sequence along the circumference of the grading ring.

[0017] In one embodiment, the outer surface of the fixing bracket is smooth and free of burrs; and / or, the fixing bracket includes a fixing portion and a connecting portion connected to the fixing portion. The fixing portion is disposed around the grading ring and fixed to the outer wall of the grading ring, and the connecting portion is fixedly connected to the grading cover.

[0018] In one embodiment, the grading cover includes a hemispherical top shell and a side enclosure plate connected to the top shell.

[0019] In one embodiment, the side enclosure plate encloses to form a wire hanging hole, and the diameter of the wire hanging hole is 230 mm to 260 mm; the outer surface of the grading cover is provided as a smooth surface.

[0020] For the above-mentioned grading device at the end of the bushing for AC withstand voltage test, on the one hand, due to the telescopic adjusting rod, the length of the telescopic adjusting rod is adjusted to drive the grading cover to move up and down, so that the grading cover covers the wiring copper bar at the end of the bushing, and the inner wall of the grading cover contacts the wiring copper bar to form an electrical connection, preventing the wiring copper bar from protruding to form a tip. It can be seen that the installation and disassembly operations of the grading cover are relatively convenient, without the need to use an aerial work vehicle or build a scaffolding, which not only saves manpower and material resources, improves the test efficiency, but also reduces the risks of equipment and personnel during the installation process; on the other hand, the grading cover is also connected to the grading ring through a fixing bracket, and the grading ring can expand the equipotential region, playing a role in suppressing tip discharge, and under the combined action with the grading cover, it can effectively suppress the corona discharge and tip discharge at the end of the bushing during the AC withstand voltage test, reducing corona loss and measurement interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural diagram of the grading device at the end of the bushing for AC withstand voltage test according to an embodiment of the present application.

[0022] Figure 2 is Figure 1 Another perspective structural diagram of the shown structure.

[0023] Figure 3 is Figure 1 A structural diagram of the shown structure ready to move up and down and be installed on the wiring copper bar.

[0024] Figure 4 is Figure 1 A structural diagram of the shown structure moving downward and being installed on the wiring copper bar.

[0025] 10. Equalizing cover; 11. Top shell; 12. Side panel; 20. Equalizing ring; 21. Air supplement joint; 30. Fixed bracket; 31. Fixed part; 32. Connecting part; 40. Telescopic adjusting rod; 401. Connector; 41. First insulating rod; 42. Second insulating rod; 43. Third insulating rod; 44. Fourth insulating rod; 45. Fifth insulating rod; 50. Wiring copper bar; 60. Support arm; 70. Locking piece. Detailed implementation manners

[0026] To make the above objects, features, and advantages of the present application more obvious and understandable, the following will describe the detailed implementation manners of the present application with reference to the accompanying drawings. Many specific details are set forth in the following description 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.

[0027] Some term explanations in this embodiment include:

[0028] GIS: Gas-insulated switchgear.

[0029] AC withstand voltage test: By applying a specified AC voltage withstand value to electrical equipment, the insulation condition of the electrical equipment is evaluated.

[0030] GIS outgoing line bushing: Supports and fixes the GIS outgoing line, and the top wiring copper bar is connected to the overhead line.

[0031] GIS temporary test tooling bushing: A temporary bushing used for the AC withstand voltage test, which needs to be removed after the test is completed.

[0032] Refer to Figures 1 to 4 , a bushing end equalizing device for AC withstand voltage test provided by an embodiment of the present application, the bushing end equalizing device for AC withstand voltage test includes: an equalizing cover 10, an equalizing ring 20, a fixed bracket 30, and a telescopic adjusting rod 40. The equalizing cover 10 is used to cover the wiring copper bar 50 at the end of the bushing. Specifically, it can be sleeved on the wiring copper bar 50 at the end of the GIS outgoing line bushing or the wiring copper bar 50 at the end of the temporary test tooling bushing, and no specific limitation is made here. The equalizing ring 20 is arranged around the circumferential direction of the equalizing cover 10 in the peripheral area of the equalizing cover 10. The equalizing ring 20 is connected to the equalizing cover 10 through the fixed bracket 30. The telescopic adjusting rod 40 can be connected to any one or more of the equalizing cover 10, the equalizing ring 20, and the fixed bracket 30.

[0033] The above-mentioned grading device for the end of the bushing used in the AC withstand voltage test, on the one hand, due to the telescopic adjusting rod 40, the length of the telescopic adjusting rod 40 is adjusted to drive the grading cover 10 to move up and down, so that the grading cover 10 covers the connection copper bar 50 at the end of the bushing. The inner wall of the grading cover 10 contacts the connection copper bar 50 to form an electrical connection, preventing the connection copper bar 50 from protruding to form a tip. It can be seen that the installation and disassembly operations of the grading cover 10 are relatively convenient, without the need to use an aerial work vehicle or erect a scaffold, which not only saves manpower and material resources, improves the test efficiency, but also reduces the risks of equipment and personnel during the installation process; on the other hand, the grading cover 10 is also connected with a grading ring 20 through a fixed bracket 30. The grading ring 20 can expand the equipotential region, play a role in suppressing tip discharge, and under the combined action with the grading cover 10, can effectively suppress the corona discharge and tip discharge at the end of the bushing during the AC withstand voltage test, reducing corona loss and measurement interference.

[0034] In addition, after the grading cover 10 covers the outside of the connection copper bar 50 at the end of the bushing, the telescopic adjusting rod 40 is continuously extended so that the bottom end of the telescopic adjusting rod 40 abuts against the ground, which can reduce the upward force exerted by the connection copper bar 50 on the grading cover 10, thereby preventing the grading cover 10 from being deformed and damaged.

[0035] In one embodiment, the grading device for the end of the bushing used in the AC withstand voltage test further includes a support arm 60 and a locking member 70. The support arm 60 is connected between the telescopic adjusting rod 40 and at least one of the grading cover 10, the grading ring 20, and the fixed bracket 30; one end of the support arm 60 is rotatably connected to the top end of the telescopic adjusting rod 40. When the support arm 60 rotates relative to the telescopic adjusting rod 40 to a preset angle, one end of the support arm 60 is fixedly connected to the top end of the telescopic adjusting end through the locking member 70. The other end of the support arm 60 is fixedly connected to at least one of the grading cover 10, the grading ring 20, and the fixed bracket 30. In this way, before installing the grading cover 10 outside the connection copper bar 50, by rotating the support arm 60, the included angle between the support arm 60 and the telescopic adjusting rod 40 is adjusted to the preset angle, and the preset angle is determined according to the inclination angle of the connection copper bar 50; after the angular position of the support arm 60 is adjusted, the angular positions of the grading cover 10 and the uniform ring are correspondingly adjusted, and then the length of the telescopic adjusting rod 40 is adjusted, which is beneficial to smoothly covering the grading cover 10 on the connection copper bar 50, and the installation operation is more flexible. In addition, the combined structure of the grading cover 10, the grading ring 20, the fixed bracket 30, and the support arm 60 is used as the first unit, which does not need to be disassembled daily; the telescopic adjusting rod 40 is used as the second unit, which does not need to be disassembled daily. When in use, the first unit and the second unit are fixedly connected through the locking member 70, and the telescopic adjusting rod 40 can be replaced according to actual needs.

[0036] In some embodiments, the locking member 70 includes, but is not limited to, bolts, screws, pins, rivets, snap connectors, etc., and can be flexibly adjusted and set according to actual needs, and will not be limited herein.

[0037] In some embodiments, taking the connection between the top end of the support arm 60 and the voltage equalizing cover 10 as an example, the connection with the voltage equalizing cover 10 includes, but is not limited to, being fixed by welding, and the surface of the welding position between the two is smooth without burrs and without tip protrusions. In addition, the support arm 60 includes, but is not limited to, being made of lightweight metal materials such as aluminum alloy or other metal materials, which can reduce the weight and extend the service life at the same time; of course, it can also be made of non-metallic materials.

[0038] In some embodiments, the bottom end of the support arm 60 has a limit and anti-slip design, and the top end of the telescopic adjusting rod 40 has a corresponding limit and anti-slip design. For example, a non-slip surface is provided at the contact position between the two, so as to be more conducive to adjusting the angle between the support arm 60 and the telescopic adjusting rod 40 to a preset angle.

[0039] In one embodiment, the telescopic adjusting rod 40 includes a plurality of insulating rods connected in sequence and capable of telescopic adjustment, and a connection head 401 connected to the insulating rod at the top end. The connection head 401 is rotatably connected to the end of the support arm 60. Specifically, the connection head 401 and the insulating rod at the top end are connected and fixed by fasteners such as rivets, etc., to prevent the connection head 401 from rotating or falling off. By telescoping and adjusting the positions of the insulating rods, for example, pulling out each insulating rod one by one, the voltage equalizing cover 10 can be raised to the same height position as the connection copper bar 50. In addition, the telescopic adjusting rod 40 is made of insulating rods, which can improve the safety performance.

[0040] In some embodiments, the number of insulating rods includes, but is not limited to, 2, 3, 4, 5, 6, 8, 10 or other numbers, and can be flexibly adjusted and set according to actual needs.

[0041] It should be noted that there are many fixing methods after one of the insulating rods is pulled out. For example, for two adjacent insulating rods, when one of the insulating rods is fully extended, the bottom end of the insulating rod is automatically connected and fixed to the top end of the other insulating rod by means of an elastic buckle, for example. It can be seen that the fixing after pulling out can be automatically realized and the automatic retraction can be realized by pressing the elastic buckle, and the operation efficiency is relatively high; for another example, when the insulating rod is moved out to a suitable position, it is connected and fixed to other insulating rods by fasteners such as pins, screws, rivets, snap connectors, etc.

[0042] In a specific embodiment, there are 5 insulating rods, namely the first insulating rod 41, the second insulating rod 42, the third insulating rod 43, the fourth insulating rod 44, and the fifth insulating rod 45. Each insulating rod is made of materials such as glass fiber and epoxy resin, with a hollow round tube design. Their lengths are all, for example, 1500 mm, the wall thickness is 5 mm, and the outer diameter increases by 10 mm. In addition, each of the heads of the second insulating rod 42, the third insulating rod 43, the fourth insulating rod 44, and the fifth insulating rod 45 has a spring limit pin, and each of the tails of the first insulating rod 41, the second insulating rod 42, the third insulating rod 43, and the fourth insulating rod 44 has a limit hole. The limit hole and the spring limit pin are mature designs and will not be elaborated here. The first insulating rod 41 can be stretched or contracted in cooperation with the second insulating rod 42, the second insulating rod 42 with the third insulating rod 43, the third insulating rod 43 with the fourth insulating rod 44, and the fourth insulating rod 44 with the fifth insulating rod 45 with different outer diameters. The maximum elongation length when the first insulating rod 41, the second insulating rod 42, the third insulating rod 43, the fourth insulating rod 44, and the fifth insulating rod 45 cooperate is about 7000 mm, and the overall insulation level is greater than 800 kV.

[0043] In some embodiments, the connector 401 is made of a metal material such as stainless steel to ensure the structural strength and improve the service life; or it is made of other non-metal materials.

[0044] In some embodiments, the telescopic adjusting rod 40 can also be set in various other telescopic adjustment ways according to actual needs, such as being set as a cylinder, a motor screw rod, etc.

[0045] In one embodiment, the grading ring 20 is provided as an airbag, and a conductive layer is provided on the outer surface of the airbag. In this way, it is light in weight, making the disassembly and assembly operations more convenient and reducing the risk of damaging the bushing.

[0046] In a specific embodiment, the grading ring 20 is an airbag made of an elastic material with a thickness of, for example, 1 mm to 5 mm. The elastic material includes but is not limited to PVC material (polyvinyl chloride material). Such an airbag has a soft material and can be easily stored and folded after deflation. In addition, when the airbag is fully inflated, it can ensure that the overall shape of the grading ring 20 is smooth and round, and the conductive layer includes but is not limited to conductive paint formed on the outer surface of the airbag by various methods such as spraying, 3D printing, electroplating, and pasting.

[0047] In some embodiments, the maximum diameter of the grading ring 20 is, for example, 800 mm, the height is, for example, 200 mm, and the total weight is less than or equal to 5 kg.

[0048] In one embodiment, the airbag is an inflatable airbag, and an air replenishing joint 21 is provided on the airbag. In this way, the grading ring 20 can be replenished with air according to actual needs.

[0049] In one embodiment, the fixing brackets 30 are provided in plurality and are sequentially arranged at intervals along the circumference of the pressure equalizing ring 20. In this way, the stability of the connection between the pressure equalizing ring 20 and the pressure equalizing cover 10 can be improved.

[0050] In some embodiments, the fixing bracket 30 includes but is not limited to being made of metal materials such as aluminum and its alloys, iron, copper, or non-metallic materials. In this embodiment, the fixing bracket 30 is specifically, for example, a metal frame, and the fixing bracket 30 is welded and fixed to the pressure equalizing ring 20 on one hand, and is welded and fixed to the pressure equalizing cover 10 made of metal material on the other hand.

[0051] In one embodiment, the outer surface of the fixing bracket 30 is smooth and burr-free. In this way, the fixing bracket 30 has no sharp protrusions, which will not cause sharp discharge phenomenon and improve safety performance.

[0052] See also Figure 1 In one embodiment, the fixing bracket 30 includes a fixing portion 31 and a connecting portion 32 connected to the fixing portion 31. The fixing portion 31 is arranged around the pressure equalizing ring 20 and fixed to the outer wall of the pressure equalizing ring 20, and the connecting portion 32 is connected and fixed to the pressure equalizing cover 10. The fixing portion 31 and the connecting portion 32 are independently arranged, and both include but are not limited to fixing rods, fixing plates, fixing strips, etc. In addition, the connecting portions 32 of all the fixing brackets 30 are respectively fixed to the four sides of the pressure equalizing cover 10, for example, by welding.

[0053] In some embodiments, the pressure equalizing cover 10 is made of metal materials including but not limited to aluminum and its alloys, iron, copper, etc. In this embodiment, the pressure equalizing cover 10 is specifically made of aluminum alloy material, which can reduce weight and cost.

[0054] In one embodiment, the voltage-equalizing cover 10 includes a hemispherical top shell 11 and a side panel 12 connected to the top shell 11. In this way, since the hemispherical top shell 11 is arranged on the top of the voltage-equalizing cover 10, the corona discharge and tip discharge generated by the copper busbar 50 at the end of the bushing can be effectively suppressed. In addition, good contact with the copper busbar 50 can be achieved.

[0055] In one embodiment, the side panels 12 enclose a wire hanging hole, and the diameter of the wire hanging hole is 230 mm to 260 mm; the outer surface of the voltage-equalizing cover 10 is set to be a smooth surface. In this way, when it is set to this size range, the voltage-equalizing cover 10 can be smoothly inserted into the copper busbar 50 at the end of the casing. In addition, the outer surface is uniformly smooth and burr-free, which effectively suppresses the corona discharge and tip discharge generated by the copper busbar 50 at the end of the casing.

[0056] The implementation process of the bushing end voltage equalizing device for AC withstand voltage test according to one embodiment is introduced as follows:

[0057] Step S100: Before the AC withstand voltage test of GIS starts, assemble the grading device at the end of the bushing for the AC withstand voltage test. According to the height and installation angle of the 220 kV GIS outgoing line bushing or the temporary test tooling bushing, adjust the angle between the support arm 60 and the connector 401 by adjusting the anti-slip limit design between them. After the angle is adjusted, lock the support arm 60 and the connector 401 with the locking member 70.

[0058] Step S200: Move the grading device under the 220 kV GIS outgoing line bushing or the temporary test tooling bushing. One operator vertically stands the lower part of the grading device on the ground, and another operator stretches the first insulating rod 41 upwards. After the tail limit hole of the first insulating rod 41 and the spring limit pin at the head of the second insulating rod 42 are locked, continue to stretch the second insulating rod 42 upwards. Stretch the second insulating rod 42, the third insulating rod 43, the fourth insulating rod 44, and the fifth insulating rod 45 respectively according to the height of the bushing connection copper bar 50 and the actual requirements to ensure that the heights of the grading ring 20 and the grading cover 10 are flush with the height of the bushing top connection copper bar 50.

[0059] Step S300: Two people jointly lift the entire grading device and put the grading cover 10 on the top connection copper bar 50 of the 220 kV GIS outgoing line bushing or the temporary test tooling bushing. By slightly rotating the fifth insulating rod 45 below, finely adjust the angular position of the upper grading cover 10 to make it contact with the bushing top connection copper bar 50. Continue to stretch the insulating rod to make the tail of the fifth insulating rod 45 contact the ground to reduce the force received by the upper grading cover 10.

[0060] Step S400: After the grading device is installed, the test wire can be connected to carry out the AC withstand voltage test of GIS. If the weight of the test wire is light, the test wire can also be connected to the support arm 60 in advance (the specific connection position can be selected according to the actual requirements as long as the contact is good and it will not fall off), so that the step of using another telescopic insulating rod to connect the test wire to the bushing end connection copper bar 50 can be omitted, improving the test efficiency. Among them, the schematic diagram during the installation process of the grading device is as Figure 3 shown, and the schematic diagram after installation is as Figure 4 shown.

[0061] Step S500: After the AC withstand voltage test is completed, refer to the steps of installing the grading device to remove the grading device.

[0062] 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. These are 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 thus should not be construed as a limitation on the present application.

[0063] In addition, if there are terms such as "first" and "second", these terms are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. 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.

[0064] In the present application, unless otherwise clearly specified and limited, if there are terms such as "mounted", "connected", "coupled", "fixed", etc., these terms should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0065] In the present application, unless otherwise clearly specified and limited, if there is a description such as a first feature being "on" or "under" a second feature, the meaning may 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 top of" the second feature may mean that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0066] It should be noted that if an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may 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 any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are only for illustrative purposes and do not represent the only implementation.

[0067] 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 described in this specification.

[0068] The above-described embodiments only represent several implementation manners of this application. The description is relatively specific and detailed, but it cannot be understood as a limitation to the scope of the patent application. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of this application, several deformations and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of this application patent should be subject to the appended claims.

Claims

1. A bushing end pressure equalizing device for AC withstand voltage test, characterized in that: The bushing end pressure equalizing device for AC withstand voltage test comprises: A voltage-equalizing cover, which is used to cover the copper busbar disposed at the end of the casing; A pressure equalizing ring, the pressure equalizing ring is arranged in the peripheral area of ​​the pressure equalizing cover in a circumferential direction around the pressure equalizing cover; A fixed bracket, through which the pressure equalizing ring is connected to the pressure equalizing cover; and A telescopic adjustment rod is connected to at least one of the pressure equalizing cover, the pressure equalizing ring and the fixing bracket.

2. The bushing end pressure equalizing device for AC withstand voltage test according to claim 1, characterized in that: The pressure equalizing device at the end of the bushing for AC withstand voltage test also includes a support arm and a locking piece, the support arm is connected between the telescopic adjustment rod and at least one of the pressure equalizing cover, the pressure equalizing ring and the fixed bracket; one end of the support arm is rotatably connected to the top end of the telescopic adjustment rod, and when the support arm is rotated to a preset angle relative to the telescopic adjustment rod, one end of the support arm is connected and fixed to the top end of the telescopic adjustment end through the locking piece; the other end of the support arm is connected and fixed to at least one of the pressure equalizing cover, the pressure equalizing ring and the fixed bracket.

3. The bushing end pressure equalizing device for AC withstand voltage test according to claim 2, characterized in that: The telescopic adjustment rod comprises a plurality of insulating rods which are connected in sequence and can be telescopically adjusted, and a connector connected to the insulating rods at the top positions, and the connector is rotatably connected to the end of the support arm.

4. The bushing end pressure equalizing device for AC withstand voltage test according to claim 1, characterized in that: The pressure equalizing ring is configured as an air bag, and a conductive layer is disposed on the outer surface of the air bag.

5. The bushing end pressure equalizing device for AC withstand voltage test according to claim 4, characterized in that: The pressure equalizing ring is an air bag made of elastic material with a thickness of 1 mm to 5 mm.

6. The bushing end pressure equalizing device for AC withstand voltage test according to claim 4, characterized in that: The airbag is an inflatable airbag and is provided with an air replenishing joint.

7. The bushing end pressure equalizing device for AC withstand voltage test according to claim 1, characterized in that: The fixing brackets are provided in plurality and are arranged in sequence and at intervals along the circumference of the pressure equalizing ring.

8. The bushing end pressure equalizing device for AC withstand voltage test according to claim 1, characterized in that: The outer surface of the fixed bracket is smooth and free of burrs; and / or the fixed bracket includes a fixed portion and a connecting portion connected to the fixed portion, the fixed portion is arranged around the pressure equalizing ring and fixed to the outer wall of the pressure equalizing ring, and the connecting portion is connected and fixed to the pressure equalizing cover.

9. The bushing end pressure equalizing device for AC withstand voltage test according to claim 1, characterized in that: The pressure equalizing cover comprises a hemispherical top shell and a side panel connected to the top shell.

10. The bushing end pressure equalizing device for AC withstand voltage test according to claim 9, characterized in that: The side panels are enclosed to form a wire hanging hole, and the diameter of the wire hanging hole is 230mm to 260mm; the outer surface of the pressure equalizing cover is set to a smooth surface.

Images