CN210272041U - Structure is wrapped to high-voltage current transformer electric capacity screen - Google Patents

Abstract

The utility model belongs to the technical field of current transformer and specifically relates to a structure is wrapped to high tension current transformer capacitive screen and specifically relates to, including first aluminium strip layer, second aluminium strip layer, interior semiconductor wrinkle paper layer and outer semiconductor wrinkle paper layer, the aluminium strip on first aluminium strip layer with interval a clockwise rare wind in on the interior semiconductor wrinkle paper layer, the aluminium strip on second aluminium strip layer with interval d anticlockwise rare wind in on the first aluminium strip layer, outer semiconductor wrinkle paper layer wind in on the second aluminium strip layer. The utility model discloses effectively reduced dielectric loss, and the difficult fracture when electric capacity screen package reaches P1-P2 and leg.

Description

Structure is wrapped to high-voltage current transformer electric capacity screen

Technical Field

The utility model belongs to the technical field of current transformer and specifically relates to a structure is wrapped to high-voltage current transformer electric capacity screen.

Background

As shown in fig. 5, the insulating structure of the capacitive screen is that some middle capacitive screens (end screens) are arranged in a thicker insulating layer of the primary coil of the high-voltage current transformer, every two capacitive screens and the insulating part between the two capacitive screens form a capacitor, the capacitive screen (zero screen) close to the primary winding is electrically connected with the primary winding, and the capacitive screen (ground screen) close to the secondary winding is grounded, so that a group of series capacitors connected between high voltage and ground potential is formed. When the number of the middle capacitive screens (end screens) is large, the field intensity of the surface of each capacitive screen is uniform, the difference of the field intensity of the surface of each capacitive screen of the series capacitor is further reduced along with the increase of the number of the capacitive screens (end screens), and the insulating medium can be fully utilized.

The traditional capacitive screen is mainly formed by half-lap winding of copper metal braided belts, and has the defects that the screen is relatively thick, and the capacitive screen is easy to crack when legs are connected in parallel from P1 to P2. Still another capacitive screen is formed by combining a stack of 1 layer of 18mm wide semiconductor paper 1/3 and a stack of 100mm wide aluminum foil 1/4, which has the disadvantages of poor stretchability of the semiconductor paper, easy cracking of the capacitive screen during wrapping and assembly of the legs P1-P2, and relatively high dielectric loss.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a structure is wrapped to high-tension current transformer electric capacity screen has effectively reduced dielectric loss, and the electric capacity screen is difficult for the fracture when wrapping and P1-P2 leg joint.

The purpose of the utility model is realized through the following technical scheme:

a wrapping structure for a capacitive screen of a high-voltage current transformer comprises a first aluminum tape layer, a second aluminum tape layer, an inner semiconductor corrugated paper layer and an outer semiconductor corrugated paper layer, wherein an aluminum tape of the first aluminum tape layer is wound on the inner semiconductor corrugated paper layer at an interval a clockwise, an aluminum tape of the second aluminum tape layer is wound on the first aluminum tape layer at an interval d anticlockwise, and the outer semiconductor corrugated paper layer is wound on the second aluminum tape layer.

The spacing a and the spacing d are equal.

The spacing a and the spacing d are equal and equal to the aluminum strip width.

The inner semiconductor crepe paper layer adopts 1 layer of semiconductor crepe paper 1/3.

The outer semiconductor crepe paper layer adopts 1 layer of semiconductor crepe paper 1/3.

The utility model discloses an advantage does with positive effect:

1. the utility model discloses an aluminium strip is earlier clockwise rare around then anticlockwise rare around, forms the latticed from this, can improve the electric conductive property of electric capacity screen under the alternating voltage, has effectively reduced dielectric loss.

2. The utility model discloses a protection of semiconductor crepe paper, its material are from taking the wrinkle, and the extensibility is good, compares in traditional semiconductor paper tape, the utility model discloses the electric capacity screen of constituteing wraps and is difficult to the fracture when P1-P2 and leg.

Drawings

Figure 1 is a schematic structural diagram of the present invention,

figure 2 is a schematic view of the first aluminum strip layer of figure 1,

figure 3 is a schematic view of the second aluminum strip layer of figure 1,

figure 4 is a complete schematic view of the aluminum strip of figure 1 being unwound,

fig. 5 is a schematic diagram of an insulation structure of a capacitive screen in the prior art.

Wherein, 1 is a first aluminum tape layer, 2 is a second aluminum tape layer, 3 is an inner semiconductor crepe paper layer, and 4 is an outer semiconductor crepe paper layer.

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

As shown in fig. 1 to 4, the present invention includes a first aluminum tape layer 1, a second aluminum tape layer 2, an inner semiconductor crepe paper layer 3 and an outer semiconductor crepe paper layer 4, wherein the inner semiconductor crepe paper layer 3 is formed by stacking 25mm wide semiconductor crepe paper 1/3 on an adjacent insulation layer, the first aluminum tape layer 1 is formed by stacking 30mm wide aluminum tapes on the inner semiconductor crepe paper layer 3 at an interval a clockwise, the second aluminum tape layer 2 is formed by stacking 30mm wide aluminum tapes on the first aluminum tape layer 1 at an interval d counterclockwise, in this embodiment, a ═ d ═ 30mm forms a grid pattern as shown in fig. 4, this structure can improve the conductivity of the capacitive screen under ac voltage, effectively reduce the dielectric loss of the product, the outer semiconductor crepe paper layer 4 is formed by stacking 25mm wide semiconductor crepe paper 1/3 on the outside of the second aluminum tape layer 2, the utility model discloses a protection of semiconductor crepe paper, it is from taking the wrinkle, and the extensibility is good, and the electric capacity screen of constitution is difficult to the fracture when containing and P1-P2 and the leg.

The first aluminum tape layer 1 and the second aluminum tape layer 2 can be formed by twice back-and-forth thin winding of the same aluminum tape, or formed by twice thin winding of two different aluminum tapes.

The utility model discloses a theory of operation does:

as shown in fig. 5, the insulation structure of the capacitive screen comprises an end screen, a ground screen and a zero screen, and the conventional capacitive screen is mainly formed by half-lapping and winding copper metal woven tapes or is formed by wrapping semiconductor paper tapes and aluminum foils.

The utility model discloses then use the wide aluminium strip of 30mm according to interval 30mm through clockwise and anticlockwise twice rare winding to become the aluminium strip layer of grid type, improved the electric conductive property of electric capacity screen under the alternating voltage, effectively reduce the dielectric loss data of product, in addition the utility model discloses utilize the protection of semiconductor crepe paper, its material is from taking the wrinkle, and the extensibility is good, compares in the semiconductor paper tape, the utility model discloses the electric capacity screen of constituteing is difficult to the fracture when surrounding and P1-P2 and leg.

The utility model discloses dielectric loss effect accessible is experimental verification as follows:

test verification records 1, all main screens and end screens of the oil-immersed vertical current transformer with the voltage level of 220kV are laminated by 1 layer of 25mm wide semiconductor crepe paper 1/3 without wrapping an aluminum tape, 100mm wide aluminum foils 1/4 are still adopted for lamination, and multiple tests prove that partial discharge is good, but the dielectric loss is about 2.5%.

Test verification record 2 all main screens and end screens of oil-immersed vertical current transformer of voltage class 220kV all follow the utility model discloses the structure uses the wide semiconductor crepe paper 1/3 of 25mm to fold 1 layer to use the wide aluminium strip of 30mm to become the grid-like package through clockwise and anticlockwise twice weak winding according to interval 30mm, through many times of experimental verification, partial discharge is good, but the dielectric loss is about 0.25% in the same time, dielectric loss greatly reduced.

The above test validation methods are well known in the art.

Claims (5)

1. The utility model provides a structure is wrapped to high-voltage current transformer electric capacity screen which characterized in that: the aluminum tape comprises a first aluminum tape layer (1), a second aluminum tape layer (2), an inner semiconductor corrugated paper layer (3) and an outer semiconductor corrugated paper layer (4), wherein the aluminum tape of the first aluminum tape layer (1) is wound on the inner semiconductor corrugated paper layer (3) at an interval a clockwise, the aluminum tape of the second aluminum tape layer (2) is wound on the first aluminum tape layer (1) at an interval d anticlockwise, and the outer semiconductor corrugated paper layer (4) is wound on the second aluminum tape layer (2).

2. The high-voltage current transformer capacitive screen wrapping structure according to claim 1, wherein: the spacing a and the spacing d are equal.

3. The high-voltage current transformer capacitive screen wrapping structure of claim 2, wherein: the spacing a and the spacing d are equal and equal to the aluminum strip width.

4. The high-voltage current transformer capacitive screen wrapping structure according to claim 1, wherein: the inner semiconductor crepe paper layer (3) adopts semiconductor crepe paper 1/3 to laminate 1 layer.

5. The high-voltage current transformer capacitive screen wrapping structure according to claim 1, wherein: the outer semiconductor crepe paper layer (4) adopts semiconductor crepe paper 1/3 to laminate 1 layer.

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