Low partial discharge bushing for switch cabinet or oil-immersed distribution transformer

Abstract

The utility model discloses a low partial discharge bushing for a switch cabinet or an oil-immersed distribution transformer, a conducting rod is used as a zero screen, a dry-type core is arranged outside the conducting rod, a silicone rubber jacket is arranged outside the dry-type core and the conducting rod, a plurality of capacitive screens are arranged in the dry-type core and used for uniformizing field intensity, a flange is sleeved on the dry-type core, and the flange is used for connecting the dry-type core and the conducting rod. The flange forms a grounding screen, and the grounding screw is in threaded connection with the flange and is connected with the capacitive screen. According to the utility model, the material and the structure of the traditional medium-voltage bushing are innovated, the conducting rod is used as a 0 screen, the flange is used as a grounding screen, the field intensity is uniform by winding crepe paper and arranging a plurality of capacitive screens in the middle, and finally, the medium-voltage bushing is manufactured by vacuum casting of pure epoxy resin, and the traditional epoxy bushing and pure porcelain bushing are replaced, so that the main insulation strength and the partial discharge performance of the bushing are greatly improved. The bushing is installed on the transformer box cover in a metal flange structure mode, installation is convenient, the risk of cracking and oil leakage is reduced, the size is small, partial discharge is low, and performance is reliable.

Description

Technical Field

[0001] This utility model relates to a low partial discharge bushing for switchgear or oil-immersed distribution transformers. Background Technology

[0002] Currently, medium-voltage bushings used in switchgear or oil-immersed distribution transformers generally adopt a pure ceramic structure. Ceramic medium-voltage bushings (such as...) Figure 1 The structure of the pure ceramic medium-voltage bushing mainly consists of a porcelain bushing, flange 6, sealing ring, conductive rod 1, washer, nut, etc. The disadvantages of pure ceramic medium-voltage bushings are that they rely primarily on transformer oil as the insulator, resulting in large size, heavy weight, and a risk of oil leakage. Summary of the Invention

[0003] This utility model provides a low partial discharge bushing for switchgear or oil-immersed distribution transformers to solve the problems existing in the prior art.

[0004] The technical solutions adopted in this utility model are as follows:

[0005] A low partial discharge bushing for switchgear or oil-immersed distribution transformers, the medium-voltage bushing being installed on the switchgear and transformer tank cover, includes a conductive rod, a silicone rubber outer sleeve, a dry core, a capacitor screen, a grounding screw, and a flange. The conductive rod serves as a zero-voltage screen, the dry core is located outside the conductive rod, the silicone rubber outer sleeve is located outside both the dry core and the conductive rod, several capacitor screens are arranged inside the dry core to uniformize the field strength, the flange is fitted onto the dry core, the flange forms a grounding screen, and the grounding screw is threaded onto the flange and connected to the capacitor screen.

[0006] Furthermore, the conductive rod is formed by winding crepe paper.

[0007] Furthermore, the dry core is formed by epoxy resin vacuum casting.

[0008] This utility model has the following beneficial effects:

[0009] This invention innovates on the materials and structure of traditional medium-voltage bushings. The conductive rod serves as the zero-voltage shield, and the flange as the grounding shield. Several capacitor shields are arranged in the middle, wrapped with crepe paper to uniformly distribute the electric field, and finally vacuum-cast with pure epoxy resin. This replaces traditional epoxy bushings and pure porcelain bushings, significantly improving the strength of the main insulation and the partial discharge performance. This bushing uses a metal flange structure and is installed on the transformer tank cover, making installation convenient, reducing the risk of cracking and oil leakage, and offering small size, low partial discharge, and reliable performance. Attached Figure Description

[0010] Figure 1 It features a traditional ceramic sleeve structure.

[0011] Figure 2 This is a structural diagram of the present utility model.

[0012] Figure 3 This is an assembly drawing of the conductive rod, dry core, capacitor screen, and flange. Detailed Implementation

[0013] The present invention will be further described below with reference to the accompanying drawings.

[0014] like Figure 2 and Figure 3 This utility model discloses a low partial discharge bushing for switchgear or oil-immersed distribution transformers, comprising a conductive rod 1, a silicone rubber outer sleeve 2, a dry core 3, a capacitor bank 4, a grounding screw 5, and a flange 6.

[0015] The conductive rod 1 serves as the 0 screen, the dry core 3 is located on the outside of the conductive rod 1, the silicone rubber jacket 2 is located on the outside of the dry core 3 and the conductive rod 1, and several capacitor screens 4 are arranged inside the dry core 3 to uniformly distribute the field strength. The flange (6) is fitted on the dry core 3, and the flange 6 forms a grounding screen. The grounding screw 5 is threaded onto the flange 6 and connected to the capacitor screen 4.

[0016] The insulating layer of the bushing uses a conductive rod as a zero-screen, wrapped with crepe paper to arrange several capacitor screens to uniformly increase the electric field strength, and then vacuum-cast and cured with pure epoxy resin. This allows for mass production and low manufacturing costs. It replaces traditional pure ceramic bushings and epoxy-cast bushings, offering advantages such as small size, low partial discharge, and reliable performance.

[0017] Conductive rod 1 serves as the 0 screen, flange 6 is the grounding screen, several capacitor screens 4 are arranged to uniformly increase the field strength by wrapping with crepe paper, and a dry core 3 is vacuum-cast with pure epoxy resin, which is then bonded to flange 6 and connected by grounding screws 5. Finally, a silicone rubber jacket 2 is bonded to it.

[0018] In this embodiment, the bushing uses a conductive rod as a zero-field shield and a flange as a grounding shield. It is wrapped with crepe paper and arranged with several capacitor screens to uniformly increase the field strength. It is formed by pure epoxy vacuum casting, replacing the traditional porcelain insulator bushing. It has the advantages of small size, low partial discharge, and reliable performance.

[0019] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present utility model, and these improvements should also be considered within the protection scope of the present utility model.

Claims

1. A low partial discharge bushing for switchgear or oil-immersed distribution transformers, characterized in that: The device includes a conductive rod (1), a silicone rubber jacket (2), a dry core (3), a capacitor screen (4), a grounding screw (5), and a flange (6). The conductive rod (1) serves as the grounding screen. The dry core (3) is located on the outside of the conductive rod (1). The silicone rubber jacket (2) is located on the outside of the dry core (3) and the conductive rod (1). Several capacitor screens (4) are arranged inside the dry core (3) to uniformize the field strength. The flange (6) is fitted on the dry core (3) and forms a grounding screen. The grounding screw (5) is threaded onto the flange (6) and connected to the capacitor screen (4).

2. The low partial discharge bushing for switchgear or oil-immersed distribution transformer as described in claim 1, characterized in that: The conductive rod (1) is formed by winding crepe paper.

3. The low partial discharge bushing for switchgear or oil-immersed distribution transformer as described in claim 1, characterized in that: The dry core (3) is formed by epoxy resin vacuum casting.

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