CN212380263U

CN212380263U - Grounding device and sleeve

Info

Publication number: CN212380263U
Application number: CN202021303495.2U
Authority: CN
Inventors: 刘文斌
Original assignee: Huailai Chibo Electrical Equipment Co ltd
Current assignee: Huailai Chibo Electrical Equipment Co ltd
Priority date: 2020-07-02
Filing date: 2020-07-02
Publication date: 2021-01-19
Anticipated expiration: 2030-07-02

Abstract

A grounding device comprises a base, a lead post, an insulating core, a lead and a top cover; a first through hole is formed in the base, a small through hole is formed in the bottom end of the first through hole and is located near a tail screen in the sleeve, and the top end of the first through hole is arranged outside the sleeve; the insulating core is made of insulating materials and is fixed in the first through hole of the base; the lead post is a hollow conductor tube, the middle part of the lead post is fixed in the insulating core, the two ends of the lead post are positioned outside the insulating core, and the lead post is fixed at the axis position of the first through hole through the insulating core and extends out of the two ends of the first through hole; one end of the lead is connected with the sleeve end screen, and the other end of the lead penetrates into the lead post from the bottom end of the lead post and is connected to the top end of the lead post; the top cover covers the top end of the first through hole of the base, and an elastic conductor is arranged in the top cover and is in elastic contact with the top end of the lead post. The grounding device has the advantages of simple structure and reliable grounding connection.

Description

Grounding device and sleeve

Technical Field

The utility model relates to a transformer bushing technical field especially relates to a capacitive transformer bushing end screen lead wire earthing device.

Background

The existing transformer is one of the most important devices in the power system as a power device for converting, transmitting and distributing electric energy in the power system, and is of great importance to the safe operation of the power system. The transformer bushing is a main insulation device outside the transformer box, and the outgoing lines of the transformer winding must penetrate through the insulation bushing to insulate the outgoing lines and the outgoing lines from the transformer shell, and meanwhile, the transformer bushing plays a role in fixing the outgoing lines.

The capacitive bushing is composed of a capacitor core, an insulating coat, a metal accessory and a conductor. The capacitor core of the capacitor bushing is composed of a plurality of layers of mutually insulated aluminum foil layers, is called as a capacitor screen, can effectively improve the distribution of an internal electric field, and improves the utilization rate of an insulating material. The more the number of the capacitive screens is, the more uniform the electric field distribution in the insulation is, wherein the first screen close to the high-voltage conductor part is a zero screen and is connected with the primary conductive part, the outermost screen is called as a tail screen, and the grounding is led out through a tail screen grounding device.

When the bushing operates in a power grid, the end screen needs to be reliably grounded, so that an electric field on the surface of the porcelain bushing with external insulation is uniformly distributed under the voltage-sharing effect of the internal capacitor core, and the capacitor core is protected, so that the electrical insulation performance of the bushing is improved.

The capacitance and dielectric loss value (dielectric loss) of the bushing capacitive screen can be measured through the end screen, so that the insulation condition of the capacitive screen is judged, the insulation performance is mastered, and therefore the leading-out terminal of the end screen grounding device is also called a test tap (test tap). The defects of damp insulation of the main end screen, degradation of insulating oil, open circuit or short circuit between the capacitive screens and the like can be effectively found through the end screen test tap.

The grounding mode of the end screen of the transformer capacitive bushing can be divided into an exposed connection mode (external type), a metal outer cover closed type (internal type) and a normally grounded mode (the tail end is grounded for a long time by the pressure of a spring, wherein a normally grounded transformer bushing end screen grounding device is the most commonly used one.

As shown in fig. 1, the normally grounded end screen grounding device adopts a rod-type sleeve grounding mode. The end screen is led out by the lead post 2, the lead post 2 is insulated to the ground, a metal grounding sleeve 22 connected with a spring 21 device is sleeved outside the lead post 2, and the metal grounding sleeve 22 is tightly contacted with the lead post 2. In normal operation, the metal grounding sleeve 22 is connected with the grounding metal flange 10 at the inner side of the sleeve by the pressure of the internal spring 21, so that the sleeve end screen is reliably grounded. The outermost part is provided with a metal sheath cover which is screwed for protection and is sealed by a sealing gasket to prevent dust and moisture from entering.

The main reason for the normal grounding type end screen grounding defect is that the outer layer grounding sleeve is not enough in spring pressure or the lead post is dirty and jammed, so that the grounding sleeve does not completely return to a normal position, the contact between the grounding sleeve and the end screen lead post is poor, and the end screen grounding fault is caused, thereby causing transformer accidents.

SUMMERY OF THE UTILITY MODEL

In order to solve the unreliable problem of common ground connection formula end screen earthing device connection among the prior art, the utility model provides an earthing device has simple structure, safe and reliable's characteristics for the sleeve pipe experiment is taken a percentage and can be kept good connected state under the condition of frequent experiment at will.

In order to achieve the above object, the present invention provides a grounding device for grounding an end screen of a capacitive bushing, comprising a base, a lead post, an insulating core, a lead, and a top cap; a first through hole is formed in the base, a small through hole is formed in the bottom end of the first through hole and is located near a tail screen in the sleeve, and the top end of the first through hole is arranged outside the sleeve; the insulating core is made of insulating materials and is fixed in the first through hole of the base; the lead post is a hollow conductor tube, the middle part of the lead post is fixed in the insulating core, the two ends of the lead post are positioned outside the insulating core, and the lead post is fixed at the axis position of the first through hole through the insulating core and extends out of the two ends of the first through hole; one end of the lead is connected with the sleeve end screen, and the other end of the lead penetrates into the lead post from the bottom end of the lead post and is connected to the top end of the lead post; the top cover covers the top end of the first through hole of the base, and an elastic conductor is arranged in the top cover and is in elastic contact with the top end of the lead post.

Preferably, the side wall of the first through hole is provided with a first thread, the top cover is provided with a second thread matched with the first thread, and the second thread is fastened to the first thread so that the elastic conductor is kept in good conductive contact with the top end of the lead post.

Preferably, the insulation core further comprises a pressure ring arranged on the upper part of the insulation core; the clamping ring is provided with a third thread matched with the first thread, and the third thread is fastened to the first thread so that the clamping ring compresses and fixes the insulating core.

Preferably, the first threaded interface is an internal threaded interface, the second threaded interface is an external threaded interface matched with the first threaded interface, and the third thread is an external threaded interface matched with the second threaded interface.

Preferably, the base is provided with a first sealing ring groove, and a first sealing rubber ring is arranged in the first sealing ring groove; the elastic conductor arranged in the top cover is M-shaped; the top cover is provided with a second sealing ring groove, and a second sealing rubber ring is arranged in the second sealing ring groove.

Preferably, the lead post is a hollow copper tube, one end of the lead is welded on the sleeve end screen, and the other end of the lead penetrates into the lead post from the bottom end of the lead post and is welded on the top end of the lead post.

The utility model provides a grounding device for transformer bushing end screen draws forth ground connection, has simple structure, and ground connection safe and reliable's characteristics for the sleeve pipe experiment is taken a percentage and can be kept good connected state under the condition of frequent experiment.

In order to solve the problem of unreliable end screen grounding of the capacitive bushing in the prior art, the utility model also provides a bushing, which comprises a capacitor core and a mounting flange, wherein the capacitor core comprises a plurality of capacitor screens, a base, a lead post, an insulating core, a lead and a top cover; a tail screen lead wire outlet hole is formed in the mounting flange; the base is arranged on the mounting flange, a first through hole is formed in the base and is communicated with the end screen lead wire outlet hole, a small through hole is formed in the bottom end of the first through hole and is located near the end screen in the sleeve, and the top end of the first through hole is arranged outside the sleeve; the insulating core is made of insulating materials and is fixed in the first through hole of the base; the lead post is a hollow conductor tube, the middle part of the lead post is fixed in the insulating core, the two ends of the lead post are positioned outside the insulating core, and the lead post is fixed at the axis position of the first through hole through the insulating core and extends out of the two ends of the first through hole; one end of the lead is connected with the end screen of the bushing capacitor core, and the other end of the lead penetrates into the lead post from the bottom end of the lead post and is connected to the top end of the lead post; the top cover covers the top end of the first through hole of the base, and an elastic conductor is arranged in the top cover and is in elastic contact with the top end of the lead post.

Preferably, the side wall of the first through hole is provided with a first thread, the top cover is provided with a second thread matched with the first thread, and the second thread is fastened to the first thread so that the elastic conductor and the top end of the lead post keep good conductive contact.

Preferably, still contain one and arrange in insulating core upper portion's clamping ring, the clamping ring setting with first screw thread matched with third screw thread, third screw thread fastening is to first screw thread makes the clamping ring will insulating core compresses tightly fixedly.

Preferably, the base is provided with a first sealing ring groove, and a first sealing rubber ring is arranged in the first sealing ring groove; an elastic conductor is arranged in the top cover and is M-shaped; the top cover is provided with a second sealing ring groove, and a second sealing rubber ring is arranged in the second sealing ring groove.

An embodiment of the utility model provides a sleeve pipe, its electric capacity core end screen lead wire ground connection have simple structure, connect safe and reliable's characteristics for the sleeve pipe experiment is taken a percentage and can be kept good connected state under the condition of frequent experiment. The technical solution of the present invention is further described in detail by the accompanying drawings and examples.

Drawings

FIG. 1 is a schematic diagram of a prior art bushing end screen grounding structure;

fig. 2 is a schematic structural diagram of a grounding device according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a structure of a second sleeve according to an embodiment of the present invention.

Detailed Description

Example one

Fig. 2 is a schematic structural diagram of a grounding device according to an embodiment of the present invention. As shown in fig. 2, the grounding device of the present embodiment is used for end screen grounding of a condenser bushing, and includes: base 1, lead wire post 2, insulating core 3, lead wire 4, top cap 5.

The base 1 is made of a hard metal, preferably a hard aluminum alloy. The base 1 is provided with a first through hole 11, and the bottom end of the first through hole 11 is provided with a small through hole 111 and is located near the end screen 61 in the sleeve. The capacitance sleeve pipe is internally provided with a capacitance core which is composed of a plurality of capacitance screens 6, and the outermost capacitance screen is a tail screen 61.

The top end of the first through hole 11 is arranged outside the sleeve, so that a passage is formed through the first through hole 11 and is communicated with the inner periphery of the sleeve near the end screen 61.

The insulating core 3 is made of insulating materials and is fixed in the first through hole 11 of the base; the insulating core 3 may be made of a hard insulating material such as ceramic, glass, nylon, or the like, or may be made by casting and curing the lead post 2 with a resin.

The lead post 2 is a hollow conductor tube, preferably made of a brass or copper hollow tube. The middle part of the lead post 2 is fixed in the insulating core, and the two ends of the lead post are positioned outside the insulating core, and the lead post 2 is fixed at the axial position of the first through hole 11 through the insulating core and extends out of the two ends of the first through hole 11; one end of the lead wire 4 is connected to the casing end screen 61, and the other end penetrates into the lead post 2 from the bottom end of the lead post 2 and is connected to the top end of the lead post 2. Preferably, one end of the lead 4 is welded to the sleeve end shield 61, and the other end is welded from the lead to the top end of the lead post 2.

The top cover 5 is made of hard metal, preferably hard aluminum alloy; the top cover 5 covers the top end of the first through hole 11 of the base, and an elastic conductor 51 is arranged in the top cover 5 and elastically contacts with the top end of the lead post. Preferably, the elastic conductor 51 is formed by pressing a stainless steel spring plate or a copper spring plate.

Preferably, the side wall of the first through hole 11 is provided with a first thread 112, the edge of the cover of the top cover 5 is provided with a second thread 52 matching with the first thread, and the second thread 52 is fastened to the first thread 112 so that the elastic conductor 51 is kept in good conductive contact with the top end of the lead post 2.

Preferably, a press ring 7 is arranged at the upper part of the insulating core 3; the press ring 7 is provided with a third thread 71 which is matched with the first thread 112, and the third thread 71 is fastened to the first thread 112 so that the press ring 7 presses and fixes the insulation core 3. Preferably, the press ring 7 is made of a good conductor of hard metal, and the top of the press ring 7 is provided with a plurality of grooves for facilitating the fastening of the third screw thread 71 to the first screw thread 112.

Preferably, the first threaded interface 112 is an internal threaded interface, the second threaded interface 52 is an external threaded interface matching with the first threaded interface 112, and the third thread 71 is an external threaded interface matching with the second threaded interface 52.

Preferably, the base 1 is provided with a first sealing ring groove 12, and a first sealing rubber ring 13 is arranged in the first sealing ring groove; an elastic conductor 51 is an M-shaped spring piece arranged in the top cover 5. The size of the opening of the M-shaped spring piece is slightly smaller than the diameter of the lead post 2, and preferably, the opening of the M-shaped spring piece is 1-3mm smaller than the lead post 2, so that good spring force can be kept for a long time, and conductive connection between the lead post 2 and the spring piece is facilitated.

Preferably, the top cover 5 is provided with a second seal ring groove 53, and a second seal rubber ring 54 is arranged inside the second seal ring groove. Establish first sealed rubber ring 13, second sealed rubber ring 54 and can prevent the utility model discloses earthing device intakes when the outdoor rain drenches, keeps the good insulating state of sleeve pipe electric capacity core.

The insulating situation of condenser sleeve pipe is its key index, can measure electric capacity and dielectric loss value (dielectric loss) of sleeve pipe electric capacity screen through the end screen to judge the insulating situation of electric capacity screen, master insulating properties, the utility model discloses end screen earthing device is when bushing apparatus moves, fastens top cap 5 on base 1 for elastic conductor 51 keeps good conductive contact with 2 tops of terminal pin, thereby makes end screen lead wire 4 good with top cap 5, base 1 conductive connection, and connect to on the sheathed tube mounting flange and ground through base 1; thus, the end screen remains well grounded while the bushing apparatus is in operation. When testing the insulating state of the sleeve, the top cover 5 is screwed down, and the end screen lead 4 is in a suspended state, so that the reliability of test data can be ensured.

An embodiment of the utility model provides a grounding device for transformer bushing end screen draws forth ground connection, has simple structure, and ground connection safe and reliable's characteristics for the sleeve pipe experiment is taken a percentage and can be kept good connected state under the condition of frequent experiment at any time.

Example two

Fig. 3 is a schematic diagram of a structure of a second sleeve according to an embodiment of the present invention. As shown in fig. 3, the condenser bushing of this embodiment includes a capacitor core 6 and a mounting flange 8, where the capacitor core 6 includes a plurality of annularly distributed capacitor screens, the outermost capacitor screen is an end screen 61, and the innermost capacitor screen is a zero screen. The mounting flange 8 is typically made of a hard metal, and when the bushing is in operation, the mounting flange 8 remains grounded. In this embodiment, the mounting flange 8 is provided with a tail screen lead wire outlet hole 81, and the tail screen lead wire 4 can penetrate through the tail screen lead wire outlet hole 81.

The condenser bushing of the present embodiment further includes a base 1, a lead post 2, an insulating core 3, a lead 4, and a cap 5. The base 1, the base 1 is made of hard metal, preferably, hard aluminum alloy; base 1 sets up on mounting flange 8, sets up first through-hole 11 on base 1 and communicates with end screen lead wire outlet 81, and the bottom of first through-hole 11 sets up a little through-hole 111 and is located near the inside end screen 61 of sleeve pipe, and the top of first through-hole 11 sets up in the sleeve pipe outside.

The lead post 2 is a hollow conductor tube, preferably made of a brass or copper hollow tube. The middle part of the lead post 2 is fixed in the insulating core 3, and two ends of the lead post are positioned outside the insulating core, and the lead post 2 is fixed at the axial position of the first through hole 11 through the insulating core 3 and extends out of two ends of the first through hole 11; one end of the lead wire 4 is connected to the casing end screen 61, and the other end penetrates into the lead post 2 from the bottom end of the lead post 2 and is connected to the top end of the lead post 2. Preferably, one end of the lead 4 is welded to the sleeve end shield 61, and the other end is welded from the lead to the top end of the lead post 2.

Preferably, the base 1 is provided with a first sealing ring groove 12, and a first sealing rubber ring 13 is arranged in the first sealing ring groove; base 1 sets up a plurality of bolt holes, and base 1 passes through the sealed fixing on mounting flange 8 of bolt, first sealed rubber ring 13, prevents the utility model discloses earthing device intakes when the outdoor rain drenches, keeps the good insulating state of sleeve pipe electric capacity core.

Preferably, an elastic conductor 51 is an M-shaped spring plate disposed in the top cover 5. The size of the opening of the M-shaped spring piece is slightly smaller than the diameter of the lead post 2, and preferably, the opening of the M-shaped spring piece is 1-3mm smaller than the lead post 2, so that good spring force can be kept for a long time, and conductive connection between the lead post 2 and the spring piece is facilitated.

The insulating situation of condenser type sheathed tube is its key index, can measure the electric capacity and the dielectric loss value (dielectric loss) of sleeve pipe electric capacity screen through the end screen to judge the insulating situation of electric capacity screen, master insulating properties, the utility model discloses end screen earthing device is when sleeve pipe equipment moves, fastens top cap 5 on base 1 for elastic conductor 51 keeps good conductive contact with 2 tops of terminal pin, thereby makes end screen lead wire 4 good with top cap 5, base 1 conductive connection, and be connected to sheathed tube mounting flange 8 through base 1 and ground connection; thus, the end screen remains well grounded while the bushing apparatus is in operation. When testing the insulating state of the sleeve, the top cover 5 is screwed down, and the end screen lead 4 is in a suspended state, so that the reliability of test data can be ensured.

An embodiment of the utility model provides a capacitor sleeve has simple structure, and ground connection safe and reliable's characteristics for the sleeve pipe experiment is taken a percentage and can be kept good connected state under the condition of frequent experiment at will.

Claims

1. A grounding device is used for grounding a capacitive bushing end screen and is characterized by comprising a base, a lead post, an insulating core, a lead and a top cover; the base is provided with a first through hole, the bottom end of the first through hole is provided with a small through hole and is positioned near the end screen in the sleeve, and the top end of the first through hole is arranged outside the sleeve; the insulating core is made of insulating materials and is fixed in the first through hole of the base; the lead post is a hollow conductor tube, the middle part of the lead post is fixed in the insulating core, the two ends of the lead post are positioned outside the insulating core, and the lead post is fixed at the axis position of the first through hole through the insulating core and extends out of the two ends of the first through hole; one end of the lead is connected to the sleeve end screen, and the other end of the lead penetrates into the lead post from the bottom end of the lead post and is connected to the top end of the lead post; the top cover covers the top end of the first through hole of the base, and an elastic conductor is arranged in the top cover and is in elastic contact with the top end of the lead post.

2. The grounding device of claim 1, wherein the first through hole sidewall is provided with a first thread, and the top cap is provided with a second thread that mates with the first thread, the second thread being fastened to the first thread such that the resilient conductor maintains good conductive contact with the lead post tip.

3. The grounding device of claim 2, further comprising a pressure ring disposed above said insulating core; the clamping ring is provided with a third thread matched with the first thread, and the third thread is fastened to the first thread so that the clamping ring compresses and fixes the insulation core.

4. The grounding device of claim 3, wherein the first threaded interface is an internally threaded interface, the second threaded interface is an externally threaded interface that mates with the first threaded interface, and the third thread is an externally threaded interface that mates with the second threaded interface.

5. The grounding device of claim 1, wherein the base is provided with a first seal ring groove in which a first seal rubber ring is arranged; the elastic conductor arranged in the top cover is M-shaped; the top cover is provided with a second sealing ring groove, and a second sealing rubber ring is arranged in the second sealing ring groove.

6. The grounding device of claim 1, wherein the lead post is a hollow copper tube, one end of the lead is welded to the bushing end shield, and the other end of the lead penetrates the lead post from the bottom end of the lead post and is welded to the top end of the lead post.

7. A sleeve comprises a capacitor core and a mounting flange, wherein the capacitor core comprises a plurality of capacitor screens and is characterized by further comprising a base, a lead post, an insulating core, a lead and a top cover; a tail screen lead wire outlet hole is formed in the mounting flange; the base is arranged on the mounting flange, a first through hole is formed in the base and is communicated with a tail screen lead wire outlet hole, a small through hole is formed in the bottom end of the first through hole and is located near a tail screen in the sleeve, and the top end of the first through hole is arranged outside the sleeve; the insulating core is made of insulating materials and is fixed in the first through hole of the base; the lead post is a hollow conductor tube, the middle part of the lead post is fixed in the insulating core, the two ends of the lead post are positioned outside the insulating core, and the lead post is fixed at the axis position of the first through hole through the insulating core and extends out of the two ends of the first through hole; one end of the lead is connected to the end screen of the bushing capacitor core, and the other end of the lead penetrates through the lead post from the bottom end of the lead post and is connected to the top end of the lead post; the top cover covers the top end of the first through hole of the base, and an elastic conductor is arranged in the top cover and is in elastic contact with the top end of the lead post.

8. The bushing of claim 7 wherein the first through hole sidewall is provided with a first thread and the cap is provided with a second thread that mates with the first thread, the second thread being secured to the first thread such that the resilient conductor maintains good conductive contact with the terminal pin tip.

9. The bushing of claim 8, further comprising a compression ring disposed above said insulating core; the clamping ring is provided with a third thread matched with the first thread, and the third thread is fastened to the first thread so that the clamping ring compresses and fixes the insulation core.

10. The cannula according to claim 7, wherein the base is provided with a first seal ring groove in which a first seal rubber ring is arranged; an elastic conductor is arranged in the top cover and is M-shaped; the top cover is provided with a second sealing ring groove, and a second sealing rubber ring is arranged in the second sealing ring groove.