CN223651250U - A type of oil-paper capacitor bushing with an anti-core sinking structure - Google Patents

Abstract

This utility model belongs to the field of high-voltage electrical equipment, specifically relating to an oil-paper capacitor bushing with an anti-core sinking structure. It includes a central conductor, an oil-paper capacitor core outside the central conductor, and a lower porcelain sleeve and an equalizing ball at the lower end of the oil-paper capacitor core. The key feature is that the tapered portion at the lower end of the oil-paper capacitor core has at least one core step. An insulating support sleeve is provided between the oil-paper capacitor core and the inner cavity of the lower porcelain sleeve. The inner wall of the insulating support sleeve has an inner cavity step that matches the core step. The insulating support sleeve supports the oil-paper capacitor core through the inner cavity step and the core step. This utility model has the advantages of reasonable structure, stable and reliable operation, and safe use.

Description

Oilpaper capacitive sleeve with core sinking prevention structure

Technical Field

The utility model belongs to the field of high-voltage electrical equipment, and particularly relates to an oilpaper capacitive sleeve with a core sinking prevention structure.

Background

In high voltage power transformers, oilpaper capacitive bushings are a critical insulating component. The core structure of the capacitor comprises an inner insulation cylindrical capacitor core body and an outer insulation cylindrical capacitor core body, wherein the inner insulation cylindrical capacitor core body is formed by rolling insulation paper and a plurality of layers of metal polar plates layer by layer on a central conductor, a special gradient structure is formed, the axial and radial electric field distribution is effectively controlled, homogenization of end field intensity is realized, and the outer insulation adopts a high-strength porcelain sleeve, so that mechanical protection is provided, and an important electric insulation effect is achieved.

Therefore, the capacitor core bearing the internal insulation is stable and reliable in the oilpaper capacitor bushing, and is a key factor for ensuring the normal operation of the transformer.

However, in the actual production process of the existing oilpaper capacitive bushing, a series of bushing failure problems may be caused due to design and process defects, wherein the sinking displacement phenomenon of the capacitive core in the bushing is the most critical.

In order to facilitate the assembly of the sleeve, a larger gap is usually reserved between the inner cavity of the sleeve oil end porcelain bushing and the capacitor core, so that when the adhesive adhesion between the innermost layer cable paper of the core and the central catheter is insufficient or the tension in the winding process of the capacitor core is smaller, the integral friction of the capacitor core on the central catheter is easily insufficient. During the operation of the sleeve, the capacitor core body can be accelerated to sink and shift along the axial direction of the central catheter in the sleeve due to the gravity of the capacitor core body and the high-frequency operation vibration.

The sinking displacement of the capacitor core body can damage the original electric field distribution, so that the discharge probability is increased, the aging process of insulating materials is accelerated, the breakdown of an insulating layer can be caused, the normal work of a ground electrode of a final screen can be influenced by the sinking displacement of the capacitor core body, the virtual grounding phenomenon is caused, the arc discharge occurs, even the explosion of a sleeve is caused, and the running reliability of a power grid is seriously influenced.

Disclosure of utility model

The utility model aims to provide an oilpaper capacitive sleeve with a core sinking prevention structure, which is characterized in that an insulating support sheath is additionally arranged on the taper part of the oilpaper capacitive core body, so that extra supporting force is provided for the oilpaper capacitive core body, the core body is effectively prevented from sinking, and the safe operation of the sleeve is ensured.

The utility model is realized by the following technical scheme:

Namely an oilpaper capacitor sleeve with a core sinking prevention structure, which comprises a central conductor, wherein an oilpaper capacitor core body is arranged outside the central conductor, a lower porcelain sleeve is arranged at the lower end of the oilpaper capacitor core body, the oilpaper capacitor sleeve is characterized in that a conical part at the lower end of the oilpaper capacitor core body is provided with at least one core body step, an insulating supporting sheath is arranged between the oilpaper capacitor core body and the inner cavity of the lower porcelain bushing, an inner cavity step matched with the core body step is arranged on the inner cavity wall of the insulating supporting sheath, and the insulating supporting sheath supports the oilpaper capacitor core body through the inner cavity step and the core body step.

Furthermore, the insulating support sheath is conical, and the taper of the inner cavity is parallel to the taper of the oil paper capacitor core body and an oil gap is reserved.

The oil gap is preferably 3-5mm.

Further, the insulating support sheath of the utility model is provided with a plurality of narrow strip-shaped oiling channels which are uniformly arranged along the axis.

Further, the insulating support sheath of the utility model is an integral structure.

The insulating support sheath of the present utility model is preferably integrally formed or injection molded.

Furthermore, the insulating support sheath is made of oil-resistant nylon or polytetrafluoroethylene.

The utility model has the following advantages and positive effects:

1) According to the oilpaper capacitive bushing, the insulating supporting sheath is additionally arranged at the taper part of the oilpaper capacitive core body, the inner cavity step of the supporting sheath is precisely matched with the core body step, the bottom of the supporting sheath is tightly butted with the sealing element in the equalizing ball, so that additional supporting force can be provided for the oilpaper capacitive core body, the weight of the oilpaper capacitive core body and various stresses in the running process can be borne, the core body can be fundamentally and effectively prevented from sinking, and the safe running of the bushing is ensured;

2) According to the oilpaper capacitive bushing, the plurality of narrow strip-shaped oiling channels which are uniformly arranged along the axis are arranged on the surface of the insulating support sheath, so that heat dissipation is facilitated, the possibility of bubble aggregation is reduced, transformer oil can freely flow in the bushing, the inside of the oilpaper capacitive core and the oil gap between the oilpaper capacitive core and the insulating support sheath can be effectively soaked, and the overall insulating performance and the long-term running reliability of the bushing are improved.

Drawings

FIG. 1 is a schematic diagram of the structure of the present utility model;

FIG. 2 is an enlarged schematic view of the portion I of FIG. 1;

FIG. 3 is a schematic view of the structure of an insulating support sheath according to the present utility model;

FIG. 4 is a schematic view of the cross-sectional structure A-A of FIG. 3;

Fig. 5 is a schematic top view of fig. 3.

The oil-filled type capacitor is shown in the figure, namely, a wiring terminal, a conservator component, an upper porcelain sleeve, a metal flange, a central conductor, an oil-filled paper capacitor core, an insulating supporting sheath, transformer oil, a lower porcelain sleeve, a lower sealing element, a pressure equalizing ball, a core step, an oil filling channel and an inner cavity step.

Detailed Description

Embodiments of the technical scheme of the present utility model will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present utility model, and thus are merely examples, and are not intended to limit the scope of the present utility model. It is noted that unless otherwise indicated, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this utility model belongs.

As shown in fig. 1 and 2, an oilpaper capacitor core 6 is arranged outside a central conductor 5, a wiring terminal 1, an oilpillow component 2, an upper porcelain bushing 3 and a metal flange 4 are sequentially arranged on the outer sides of the upper parts of the central conductor 5 and the oilpaper capacitor core 6 from top to bottom, a lower porcelain bushing 9, a lower sealing element 10 and a pressure equalizing ball 11 are sequentially arranged on the outer sides of the lower parts of the central conductor 5 and the oilpaper capacitor core 6 from top to bottom, an annular core step 12 is arranged at the conical part of the oil end of the oilpaper capacitor core 6, an insulating support sheath 7 is arranged between the oilpaper capacitor core 6 and the inner cavity of the lower porcelain bushing 9, an inner cavity step 14 matched with the core step 12 is arranged on the inner cavity wall of the insulating support sheath 7, the lower end of the insulating support sheath 7 is tightly matched with the lower sealing element 11 in the pressure equalizing ball 11 (namely, the lower end of the insulating support sheath 7 is pressed on the lower sealing element 11), and the insulating support sheath 7 supports the oilpaper capacitor core 6 through the inner cavity step 14 and the core step 12.

As shown in fig. 3, 4 and 5, the surface of the insulating support sheath 7 is provided with a plurality of narrow strip-shaped oiling channels 13 which are uniformly arranged along the axis.

The following describes the manufacturing process of the present utility model by taking the manufacturing of a 252kV oiled paper capacitive transformer bushing as an example:

Firstly, preparing a dried 252kV oil paper capacitor core 6, penetrating a metal flange 4 through the oil end of the oil paper capacitor core 6, installing the metal flange at the middle lower end part of the oil paper capacitor core 6, installing an insulating support sheath 7 at the oil end of the oil paper capacitor core 6, penetrating the insulating support sheath 7 through the tail end of a central conductor 5, installing the insulating support sheath 7 at the oil end taper part of the oil paper capacitor core 6, installing a lower porcelain bushing 9, screwing down a lower sealing piece 10, enabling the insulating support sheath 7 to be in close contact with a step 12 at the oil end of the oil paper capacitor core 6, sequentially installing the porcelain bushing 3 and a conservator assembly 2 at the air end part, finally installing a connecting terminal 1 and a voltage equalizing ball 11, completing the whole assembly work of a bushing, and finally vacuumizing the bushing to inject qualified transformer oil 8, thus completing the manufacture of a complete 252kV oil paper capacitor transformer bushing.

The embodiments are only used to illustrate the technical scheme of the present utility model, but not to limit the technical scheme, and although the present utility model has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical scheme described in the foregoing embodiments may be modified or some or all technical features may be equivalently replaced, and the modification or replacement does not make the essence of the corresponding technical scheme deviate from the scope of the technical scheme of the embodiments of the present utility model, and is included in the scope of the claims and the specification of the present utility model.

Claims (5)

1. The utility model provides an oilpaper electric capacity formula sleeve pipe with prevent core sinking structure, including the center conductor, the outside oilpaper electric capacity core that is equipped with of center conductor, the lower extreme of oilpaper electric capacity core is equipped with porcelain bushing and voltage-sharing ball down, its characterized in that, the toper part of oilpaper electric capacity core lower extreme is equipped with at least one core step, is equipped with insulating support sheath between oilpaper electric capacity core and lower porcelain bushing inner chamber, is equipped with the inner chamber step that matches with the core step on insulating support sheath's the inner chamber wall, insulating support sheath supports oilpaper electric capacity core through inner chamber step, core step.

2. The oilpaper capacitive bushing with a core sinking prevention structure according to claim 1, wherein the insulating support sheath is tapered, and the taper of the inner cavity is parallel to the taper of the oilpaper capacitive core and leaves an oil gap.

3. An oilpaper capacitive bushing with a core sinking prevention structure according to claim 1, wherein the insulating support jacket surface is provided with a plurality of narrow strip-shaped oiling channels uniformly aligned along the axis.

4. The oilpaper capacitive bushing with a core sinking prevention structure according to claim 1, wherein the insulating support sheath is of an integral structure.

5. An oilpaper capacitive bushing with a core sinking prevention structure according to claim 1, 2, 3 or 4, wherein the insulating support sheath is made of oil-resistant nylon or polytetrafluoroethylene.