CN205845681U - Layer coils for oil-filled distribution transformers - Google Patents

Abstract

The utility model relates to a layered coil for an oil-immersed distribution transformer, which comprises a plurality of layers of low-voltage coils and high-voltage coils wound in sequence inside and outside, a main empty channel is formed between the high-voltage coil and the low-voltage coil, and the high-voltage coil Wound on the outside of the main airway, the high-voltage coil is wound with the first layer coil, the second layer coil to the Nth layer coil sequentially from the inside to the outside, and there are also respective sets of coils between two adjacent coils of the high-voltage coil. The interlayer insulating layer, the upper end and the lower end of the high-voltage coil are respectively provided with a stepped insulating layer, and the thickness of the insulating layer located on the inner side is greater than that of the insulating layer located on the outer side. The beneficial effect of the utility model is that the electrical insulation strength between the high-voltage coil and the low-voltage coil is improved.

Description

Layer coils for oil-filled distribution transformers

technical field

The utility model relates to the field of transformers, in particular to a layered coil for an oil-immersed distribution transformer.

Background technique

The structure of the oil-immersed distribution transformer is relatively simple. The high and low voltage generally adopt layered coils. The high voltage coil is wound outside the low voltage coil. A main channel is set between the high and low voltage coils. The main channel adopts an insulating cardboard oil channel structure. In order to improve the filling factor of the wires in the core window, the size of the coil's end turns and the main empty channel is constantly shrinking. In order to ensure that the filling factor is increased without reducing the insulation strength, a positive-angle ring is arranged at the end of the high-voltage coil in the traditional structure, but this structure makes the coil process complicated and easily affects the heat dissipation of the coil.

Contents of the invention

The purpose of this utility model is to provide a layered coil for oil-immersed distribution transformers to improve the electrical insulation strength between the high-voltage coil and the low-voltage coil.

The solution adopted by the utility model to solve the technical problem is: a layered coil used for oil-immersed distribution transformers, including several layers of low-voltage coils and high-voltage coils wound around the inside and outside in turn, forming a gap between the high-voltage coils and the low-voltage coils. The main airway is characterized in that: the high-voltage coil is wound on the outside of the main airway, and the high-voltage coil is wound with the first layer coil, the second layer coil to the Nth layer coil sequentially from the inside to the outside, and the high-voltage wire An interlayer insulation layer is also provided between two adjacent coils of the coil. The upper and lower ends of the high-voltage coil are respectively provided with a stepped insulation layer, and the thickness of the insulation layer on the inner side is greater than that on the outer side.

Further, the thickness of the insulating layer is greater than 10mm and less than 30mm.

Further, the insulating layer is composed of insulating cardboard.

Further, the interlayer insulating layer is composed of cable paper.

Further, the main air passage includes oil passages and insulating cardboard arranged inside and outside in sequence, and the insulating cardboard is attached between the outer wall of the oil passage and the first layer of coils.

Further, the wire inlet end of the high-voltage coil is located at the upper end of the first-layer coil.

Compared with the prior art, the utility model has the following beneficial effects: the layered coil provided by the utility model improves the electrical insulation strength between the high-voltage coil and the low-voltage coil, and the end of the main airway between the high-voltage coil and the low-voltage coil The electric field distortion is serious, and it is the weakest link of insulation. When the high-voltage coil encounters overvoltage such as lightning shock, it is easy to creep along the end of the main channel to the low-voltage coil, causing insulation breakdown. The layered coil provided by the utility model The structure of the insulating layer in the coil lengthens the creepage distance of the wire along the end of the main channel; in addition, compared with the angle ring used between the high-voltage coil and the low-voltage coil, the process is simple, and the heat dissipation of the coil will not be affected by improper handling of the angle ring .

Description of drawings

Below in conjunction with accompanying drawing, the utility model patent is further described.

FIG. 1 is a schematic structural diagram of a layered coil according to an embodiment of the present invention.

In the figure: 1- high voltage coil; 10- first layer coil; 11- second layer coil; 12- Nth layer coil; 13- interlayer insulation layer; 2- low voltage coil; 3- insulating cardboard; 4- oil channel ; 5 - insulating layer.

detailed description

Below in conjunction with accompanying drawing and specific embodiment the utility model is further described.

As shown in Figure 1, a layered coil for an oil-immersed distribution transformer in this embodiment includes several layers of low-voltage coils 2 and high-voltage coils 1 wound in sequence inside and outside, and between the high-voltage coil 1 and the low-voltage coil 2 A main channel is formed, which is characterized in that: the high-voltage coil 1 is wound on the outside of the main channel, and the high-voltage coil 1 is wound with a first-layer coil 10, a second-layer coil 11 to Nth layer coil 12, interlayer insulating layers 13 are respectively provided between two adjacent coils of the high-voltage coil 1, and a stepped insulating layer 5 is respectively provided at the upper end and the lower end of the high-voltage coil 1, and the insulating layer located on the inner side The thickness of 5 is greater than the thickness of the insulating layer 5 located outside.

As can be seen from the above, the beneficial effect of the utility model is that: the structure of the insulating layer 5 in the layered coil provided by the utility model, by increasing the thickness of the inner insulating layer 5, lengthens the creepage distance of the wire along the end of the main empty passage, and the wire The incoming wire end of the coil is located at the upper end of the inner first-layer coil. Compared with the traditional angle ring between the high-voltage coil 1 and the low-voltage coil 2, the layer-type coil of this structure has a simple process, and it will not be caused by improper handling of the angle ring. , affecting the heat dissipation of the coil.

In this embodiment, the thickness of the insulating layer 5 is greater than 10mm and less than 30mm. According to the insulation strength of the high-voltage coil 1 and the low-voltage coil 2, the thickness of the insulating layer 5 located inside can be correspondingly increased.

In this embodiment, the insulating layer 5 is composed of insulating cardboard 3 . It is composed of 3 superimposed insulating cardboards, which is convenient for production.

In this embodiment, the interlayer insulating layer 5 is composed of cable paper.

In this embodiment, the main air channel includes an oil channel 4 and an insulating cardboard 3 arranged inside and outside in sequence, and the insulating cardboard 3 is attached between the outer wall of the oil channel 4 and the first-layer coil 10 .

In this embodiment, the wire inlet end of the high voltage coil 1 is located at the upper end of the first layer coil 10 . The creepage distance of the wire along the end of the main airway is lengthened, and the insulation strength between the high-voltage coil 1 and the low-voltage coil 2 is improved.

The utility model will be further explained through the specific implementation process of this embodiment below.

First, the high-voltage coil 1 is wound from the inside to the outside through a wire to form the first layer coil 10, the second layer coil 11 to the Nth layer coil 12, and the incoming wire end of the wire is located at the upper end of the first layer coil 10, and the outgoing wire section is located at the second layer coil. N-layer coils 13; interlayer insulating layers 14 are respectively provided between two adjacent coils of the high-voltage coil 1; A main air channel, an oil channel 4 and an insulating cardboard 3 are arranged inside and outside the main channel, and the insulating cardboard 3 is pasted between the outer wall of the oil channel 4 and the first-layer coil; the upper end and the lower end of the high-voltage coil 1 are respectively fixedly connected The insulating layer 5 is stepped, and the insulating layer 5 is formed by superimposing and cutting several insulating cardboards 3 . The inner insulating layer 5 is thicker than the outer insulating layer 5, the inner insulating layer 5 is thicker than 20mm, and the outer insulating layer 5 is thicker than 10mm.

In summary, the utility model provides a layered coil for oil-immersed distribution transformers. By increasing the thickness of the inner insulating layer, the creepage distance of the wire along the end of the main channel is lengthened, and the high-voltage coil is improved. and the electrical insulation strength between the low voltage coil.

The above preferred embodiments have further described the purpose, technical solutions and advantages of the utility model in detail. It should be understood that the above descriptions are only preferred embodiments of the utility model and are not intended to limit the utility model. For new models, any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims (6)

1. for a layer-type winding for oil immersion-type distribution transformer, if being arranged with dried layer low-voltage coil and height inside and outside including successively Line ball circle, forms a main empty path between high-tension coil and low-voltage coil, it is characterised in that: described high-tension coil is set around described master The outside in empty road, described high-tension coil is arranged with ground floor coil, second layer coil the most successively to n-th layer coil, its Middle N is the positive integer more than 3；Interlayer insulating film, described high-tension coil also each it is provided with between two adjacent windings of high-tension coil Top and bottom are respectively equipped with one in stepped insulating barrier, are positioned at the thickness of insulating barrier of inner side more than the insulation being positioned at outside The thickness of layer.

Layer-type winding for oil immersion-type distribution transformer the most according to claim 1, it is characterised in that: described insulating barrier Thickness more than 10mm, and less than 30mm.

Layer-type winding for oil immersion-type distribution transformer the most according to claim 1, it is characterised in that: described insulating barrier It is made up of insulating board.

Layer-type winding for oil immersion-type distribution transformer the most according to claim 1, it is characterised in that: described interlayer is exhausted Edge layer is made up of cable paper.

Layer-type winding for oil immersion-type distribution transformer the most according to claim 1, it is characterised in that: described main empty path The oil duct set gradually inside and outside including and insulating board, described insulating board be sticked with described oil duct outer wall and ground floor coil it Between.

Layer-type winding for oil immersion-type distribution transformer the most according to claim 1, it is characterised in that: described high-voltage line The wire end of incoming cables of circle is positioned at the upper end of ground floor coil.